Commit Graph

7478 Commits

Author SHA1 Message Date
6446369fb9 net: fix NULL pointer in skb_segment_list
commit 876e8ca836 upstream.

Commit 3a1296a38d ("net: Support GRO/GSO fraglist chaining.")
introduced UDP listifyed GRO. The segmentation relies on frag_list being
untouched when passing through the network stack. This assumption can be
broken sometimes, where frag_list itself gets pulled into linear area,
leaving frag_list being NULL. When this happens it can trigger
following NULL pointer dereference, and panic the kernel. Reverse the
test condition should fix it.

[19185.577801][    C1] BUG: kernel NULL pointer dereference, address:
...
[19185.663775][    C1] RIP: 0010:skb_segment_list+0x1cc/0x390
...
[19185.834644][    C1] Call Trace:
[19185.841730][    C1]  <TASK>
[19185.848563][    C1]  __udp_gso_segment+0x33e/0x510
[19185.857370][    C1]  inet_gso_segment+0x15b/0x3e0
[19185.866059][    C1]  skb_mac_gso_segment+0x97/0x110
[19185.874939][    C1]  __skb_gso_segment+0xb2/0x160
[19185.883646][    C1]  udp_queue_rcv_skb+0xc3/0x1d0
[19185.892319][    C1]  udp_unicast_rcv_skb+0x75/0x90
[19185.900979][    C1]  ip_protocol_deliver_rcu+0xd2/0x200
[19185.910003][    C1]  ip_local_deliver_finish+0x44/0x60
[19185.918757][    C1]  __netif_receive_skb_one_core+0x8b/0xa0
[19185.927834][    C1]  process_backlog+0x88/0x130
[19185.935840][    C1]  __napi_poll+0x27/0x150
[19185.943447][    C1]  net_rx_action+0x27e/0x5f0
[19185.951331][    C1]  ? mlx5_cq_tasklet_cb+0x70/0x160 [mlx5_core]
[19185.960848][    C1]  __do_softirq+0xbc/0x25d
[19185.968607][    C1]  irq_exit_rcu+0x83/0xb0
[19185.976247][    C1]  common_interrupt+0x43/0xa0
[19185.984235][    C1]  asm_common_interrupt+0x22/0x40
...
[19186.094106][    C1]  </TASK>

Fixes: 3a1296a38d ("net: Support GRO/GSO fraglist chaining.")
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/Y9gt5EUizK1UImEP@debian
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-06 07:56:16 +01:00
d4c008f3b7 net: fix UaF in netns ops registration error path
[ Upstream commit 71ab9c3e22 ]

If net_assign_generic() fails, the current error path in ops_init() tries
to clear the gen pointer slot. Anyway, in such error path, the gen pointer
itself has not been modified yet, and the existing and accessed one is
smaller than the accessed index, causing an out-of-bounds error:

 BUG: KASAN: slab-out-of-bounds in ops_init+0x2de/0x320
 Write of size 8 at addr ffff888109124978 by task modprobe/1018

 CPU: 2 PID: 1018 Comm: modprobe Not tainted 6.2.0-rc2.mptcp_ae5ac65fbed5+ #1641
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.1-2.fc37 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x6a/0x9f
  print_address_description.constprop.0+0x86/0x2b5
  print_report+0x11b/0x1fb
  kasan_report+0x87/0xc0
  ops_init+0x2de/0x320
  register_pernet_operations+0x2e4/0x750
  register_pernet_subsys+0x24/0x40
  tcf_register_action+0x9f/0x560
  do_one_initcall+0xf9/0x570
  do_init_module+0x190/0x650
  load_module+0x1fa5/0x23c0
  __do_sys_finit_module+0x10d/0x1b0
  do_syscall_64+0x58/0x80
  entry_SYSCALL_64_after_hwframe+0x72/0xdc
 RIP: 0033:0x7f42518f778d
 Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48
       89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
       ff 73 01 c3 48 8b 0d cb 56 2c 00 f7 d8 64 89 01 48
 RSP: 002b:00007fff96869688 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
 RAX: ffffffffffffffda RBX: 00005568ef7f7c90 RCX: 00007f42518f778d
 RDX: 0000000000000000 RSI: 00005568ef41d796 RDI: 0000000000000003
 RBP: 00005568ef41d796 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
 R13: 00005568ef7f7d30 R14: 0000000000040000 R15: 0000000000000000
  </TASK>

This change addresses the issue by skipping the gen pointer
de-reference in the mentioned error-path.

Found by code inspection and verified with explicit error injection
on a kasan-enabled kernel.

Fixes: d266935ac4 ("net: fix UAF issue in nfqnl_nf_hook_drop() when ops_init() failed")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/cec4e0f3bb2c77ac03a6154a8508d3930beb5f0f.1674154348.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-01 08:23:24 +01:00
e68e088d0d bpf: pull before calling skb_postpull_rcsum()
[ Upstream commit 54c3f1a814 ]

Anand hit a BUG() when pulling off headers on egress to a SW tunnel.
We get to skb_checksum_help() with an invalid checksum offset
(commit d7ea0d9df2 ("net: remove two BUG() from skb_checksum_help()")
converted those BUGs to WARN_ONs()).
He points out oddness in how skb_postpull_rcsum() gets used.
Indeed looks like we should pull before "postpull", otherwise
the CHECKSUM_PARTIAL fixup from skb_postpull_rcsum() will not
be able to do its job:

	if (skb->ip_summed == CHECKSUM_PARTIAL &&
	    skb_checksum_start_offset(skb) < 0)
		skb->ip_summed = CHECKSUM_NONE;

Reported-by: Anand Parthasarathy <anpartha@meta.com>
Fixes: 6578171a7f ("bpf: add bpf_skb_change_proto helper")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20221220004701.402165-1-kuba@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:44 +01:00
037db10e3f net: add atomic_long_t to net_device_stats fields
[ Upstream commit 6c1c509778 ]

Long standing KCSAN issues are caused by data-race around
some dev->stats changes.

Most performance critical paths already use per-cpu
variables, or per-queue ones.

It is reasonable (and more correct) to use atomic operations
for the slow paths.

This patch adds an union for each field of net_device_stats,
so that we can convert paths that are not yet protected
by a spinlock or a mutex.

netdev_stats_to_stats64() no longer has an #if BITS_PER_LONG==64

Note that the memcpy() we were using on 64bit arches
had no provision to avoid load-tearing,
while atomic_long_read() is providing the needed protection
at no cost.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:18 +01:00
6d935a0265 bpf: make sure skb->len != 0 when redirecting to a tunneling device
[ Upstream commit 07ec7b5028 ]

syzkaller managed to trigger another case where skb->len == 0
when we enter __dev_queue_xmit:

WARNING: CPU: 0 PID: 2470 at include/linux/skbuff.h:2576 skb_assert_len include/linux/skbuff.h:2576 [inline]
WARNING: CPU: 0 PID: 2470 at include/linux/skbuff.h:2576 __dev_queue_xmit+0x2069/0x35e0 net/core/dev.c:4295

Call Trace:
 dev_queue_xmit+0x17/0x20 net/core/dev.c:4406
 __bpf_tx_skb net/core/filter.c:2115 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2140 [inline]
 __bpf_redirect+0x5fb/0xda0 net/core/filter.c:2163
 ____bpf_clone_redirect net/core/filter.c:2447 [inline]
 bpf_clone_redirect+0x247/0x390 net/core/filter.c:2419
 bpf_prog_48159a89cb4a9a16+0x59/0x5e
 bpf_dispatcher_nop_func include/linux/bpf.h:897 [inline]
 __bpf_prog_run include/linux/filter.h:596 [inline]
 bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_test_run+0x46c/0x890 net/bpf/test_run.c:402
 bpf_prog_test_run_skb+0xbdc/0x14c0 net/bpf/test_run.c:1170
 bpf_prog_test_run+0x345/0x3c0 kernel/bpf/syscall.c:3648
 __sys_bpf+0x43a/0x6c0 kernel/bpf/syscall.c:5005
 __do_sys_bpf kernel/bpf/syscall.c:5091 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5089 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5089
 do_syscall_64+0x54/0x70 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x61/0xc6

The reproducer doesn't really reproduce outside of syzkaller
environment, so I'm taking a guess here. It looks like we
do generate correct ETH_HLEN-sized packet, but we redirect
the packet to the tunneling device. Before we do so, we
__skb_pull l2 header and arrive again at skb->len == 0.
Doesn't seem like we can do anything better than having
an explicit check after __skb_pull?

Cc: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+f635e86ec3fa0a37e019@syzkaller.appspotmail.com
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20221027225537.353077-1-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:15 +01:00
9062493811 net: stream: purge sk_error_queue in sk_stream_kill_queues()
[ Upstream commit e0c8bccd40 ]

Changheon Lee reported TCP socket leaks, with a nice repro.

It seems we leak TCP sockets with the following sequence:

1) SOF_TIMESTAMPING_TX_ACK is enabled on the socket.

   Each ACK will cook an skb put in error queue, from __skb_tstamp_tx().
   __skb_tstamp_tx() is using skb_clone(), unless
   SOF_TIMESTAMPING_OPT_TSONLY was also requested.

2) If the application is also using MSG_ZEROCOPY, then we put in the
   error queue cloned skbs that had a struct ubuf_info attached to them.

   Whenever an struct ubuf_info is allocated, sock_zerocopy_alloc()
   does a sock_hold().

   As long as the cloned skbs are still in sk_error_queue,
   socket refcount is kept elevated.

3) Application closes the socket, while error queue is not empty.

Since tcp_close() no longer purges the socket error queue,
we might end up with a TCP socket with at least one skb in
error queue keeping the socket alive forever.

This bug can be (ab)used to consume all kernel memory
and freeze the host.

We need to purge the error queue, with proper synchronization
against concurrent writers.

Fixes: 24bcbe1cc6 ("net: stream: don't purge sk_error_queue in sk_stream_kill_queues()")
Reported-by: Changheon Lee <darklight2357@icloud.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:12 +01:00
821be5a5ab skbuff: Account for tail adjustment during pull operations
[ Upstream commit 2d7afdcbc9 ]

Extending the tail can have some unexpected side effects if a program uses
a helper like BPF_FUNC_skb_pull_data to read partial content beyond the
head skb headlen when all the skbs in the gso frag_list are linear with no
head_frag -

  kernel BUG at net/core/skbuff.c:4219!
  pc : skb_segment+0xcf4/0xd2c
  lr : skb_segment+0x63c/0xd2c
  Call trace:
   skb_segment+0xcf4/0xd2c
   __udp_gso_segment+0xa4/0x544
   udp4_ufo_fragment+0x184/0x1c0
   inet_gso_segment+0x16c/0x3a4
   skb_mac_gso_segment+0xd4/0x1b0
   __skb_gso_segment+0xcc/0x12c
   udp_rcv_segment+0x54/0x16c
   udp_queue_rcv_skb+0x78/0x144
   udp_unicast_rcv_skb+0x8c/0xa4
   __udp4_lib_rcv+0x490/0x68c
   udp_rcv+0x20/0x30
   ip_protocol_deliver_rcu+0x1b0/0x33c
   ip_local_deliver+0xd8/0x1f0
   ip_rcv+0x98/0x1a4
   deliver_ptype_list_skb+0x98/0x1ec
   __netif_receive_skb_core+0x978/0xc60

Fix this by marking these skbs as GSO_DODGY so segmentation can handle
the tail updates accordingly.

Fixes: 3dcbdb134f ("net: gso: Fix skb_segment splat when splitting gso_size mangled skb having linear-headed frag_list")
Signed-off-by: Sean Tranchetti <quic_stranche@quicinc.com>
Signed-off-by: Subash Abhinov Kasiviswanathan <quic_subashab@quicinc.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Link: https://lore.kernel.org/r/1671084718-24796-1-git-send-email-quic_subashab@quicinc.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:12 +01:00
4794d07fe6 net: add inline function skb_csum_is_sctp
[ Upstream commit fa82117010 ]

This patch is to define a inline function skb_csum_is_sctp(), and
also replace all places where it checks if it's a SCTP CSUM skb.
This function would be used later in many networking drivers in
the following patches.

Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: db0b124f02 ("igc: Enhance Qbv scheduling by using first flag bit")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:10 +01:00
67349025f0 net: switch to storing KCOV handle directly in sk_buff
[ Upstream commit fa69ee5aa4 ]

It turns out that usage of skb extensions can cause memory leaks. Ido
Schimmel reported: "[...] there are instances that blindly overwrite
'skb->extensions' by invoking skb_copy_header() after __alloc_skb()."

Therefore, give up on using skb extensions for KCOV handle, and instead
directly store kcov_handle in sk_buff.

Fixes: 6370cc3bbd ("net: add kcov handle to skb extensions")
Fixes: 85ce50d337 ("net: kcov: don't select SKB_EXTENSIONS when there is no NET")
Fixes: 97f53a08cb ("net: linux/skbuff.h: combine SKB_EXTENSIONS + KCOV handling")
Link: https://lore.kernel.org/linux-wireless/20201121160941.GA485907@shredder.lan/
Reported-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20201125224840.2014773-1-elver@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: db0b124f02 ("igc: Enhance Qbv scheduling by using first flag bit")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:10 +01:00
be719496ae bpf, sockmap: fix race in sock_map_free()
[ Upstream commit 0a182f8d60 ]

sock_map_free() calls release_sock(sk) without owning a reference
on the socket. This can cause use-after-free as syzbot found [1]

Jakub Sitnicki already took care of a similar issue
in sock_hash_free() in commit 75e68e5bf2 ("bpf, sockhash:
Synchronize delete from bucket list on map free")

[1]
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 0 PID: 3785 at lib/refcount.c:31 refcount_warn_saturate+0x17c/0x1a0 lib/refcount.c:31
Modules linked in:
CPU: 0 PID: 3785 Comm: kworker/u4:6 Not tainted 6.1.0-rc7-syzkaller-00103-gef4d3ea40565 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: events_unbound bpf_map_free_deferred
RIP: 0010:refcount_warn_saturate+0x17c/0x1a0 lib/refcount.c:31
Code: 68 8b 31 c0 e8 75 71 15 fd 0f 0b e9 64 ff ff ff e8 d9 6e 4e fd c6 05 62 9c 3d 0a 01 48 c7 c7 80 bb 68 8b 31 c0 e8 54 71 15 fd <0f> 0b e9 43 ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c a2 fe ff
RSP: 0018:ffffc9000456fb60 EFLAGS: 00010246
RAX: eae59bab72dcd700 RBX: 0000000000000004 RCX: ffff8880207057c0
RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000
RBP: 0000000000000004 R08: ffffffff816fdabd R09: fffff520008adee5
R10: fffff520008adee5 R11: 1ffff920008adee4 R12: 0000000000000004
R13: dffffc0000000000 R14: ffff88807b1c6c00 R15: 1ffff1100f638dcf
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30c30000 CR3: 000000000d08e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__refcount_dec include/linux/refcount.h:344 [inline]
refcount_dec include/linux/refcount.h:359 [inline]
__sock_put include/net/sock.h:779 [inline]
tcp_release_cb+0x2d0/0x360 net/ipv4/tcp_output.c:1092
release_sock+0xaf/0x1c0 net/core/sock.c:3468
sock_map_free+0x219/0x2c0 net/core/sock_map.c:356
process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>

Fixes: 7e81a35302 ("bpf: Sockmap, ensure sock lock held during tear down")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Song Liu <songliubraving@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20221202111640.2745533-1-edumazet@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:15:37 +01:00
0d6ae25da5 bpf: Move skb->len == 0 checks into __bpf_redirect
[ Upstream commit 114039b342 ]

To avoid potentially breaking existing users.

Both mac/no-mac cases have to be amended; mac_header >= network_header
is not enough (verified with a new test, see next patch).

Fixes: fd18942244 ("bpf: Don't redirect packets with invalid pkt_len")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20221121180340.1983627-1-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:15:31 +01:00
5c97af75f5 netfilter: conntrack: Fix data-races around ct mark
[ Upstream commit 52d1aa8b82 ]

nf_conn:mark can be read from and written to in parallel. Use
READ_ONCE()/WRITE_ONCE() for reads and writes to prevent unwanted
compiler optimizations.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-02 17:40:00 +01:00
50868de7dc net: gso: fix panic on frag_list with mixed head alloc types
[ Upstream commit 9e4b7a99a0 ]

Since commit 3dcbdb134f ("net: gso: Fix skb_segment splat when
splitting gso_size mangled skb having linear-headed frag_list"), it is
allowed to change gso_size of a GRO packet. However, that commit assumes
that "checking the first list_skb member suffices; i.e if either of the
list_skb members have non head_frag head, then the first one has too".

It turns out this assumption does not hold. We've seen BUG_ON being hit
in skb_segment when skbs on the frag_list had differing head_frag with
the vmxnet3 driver. This happens because __netdev_alloc_skb and
__napi_alloc_skb can return a skb that is page backed or kmalloced
depending on the requested size. As the result, the last small skb in
the GRO packet can be kmalloced.

There are three different locations where this can be fixed:

(1) We could check head_frag in GRO and not allow GROing skbs with
    different head_frag. However, that would lead to performance
    regression on normal forward paths with unmodified gso_size, where
    !head_frag in the last packet is not a problem.

(2) Set a flag in bpf_skb_net_grow and bpf_skb_net_shrink indicating
    that NETIF_F_SG is undesirable. That would need to eat a bit in
    sk_buff. Furthermore, that flag can be unset when all skbs on the
    frag_list are page backed. To retain good performance,
    bpf_skb_net_grow/shrink would have to walk the frag_list.

(3) Walk the frag_list in skb_segment when determining whether
    NETIF_F_SG should be cleared. This of course slows things down.

This patch implements (3). To limit the performance impact in
skb_segment, the list is walked only for skbs with SKB_GSO_DODGY set
that have gso_size changed. Normal paths thus will not hit it.

We could check only the last skb but since we need to walk the whole
list anyway, let's stay on the safe side.

Fixes: 3dcbdb134f ("net: gso: Fix skb_segment splat when splitting gso_size mangled skb having linear-headed frag_list")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/e04426a6a91baf4d1081e1b478c82b5de25fdf21.1667407944.git.jbenc@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-16 09:57:09 +01:00
1c89642e7f net, neigh: Fix null-ptr-deref in neigh_table_clear()
[ Upstream commit f8017317cb ]

When IPv6 module gets initialized but hits an error in the middle,
kenel panic with:

KASAN: null-ptr-deref in range [0x0000000000000598-0x000000000000059f]
CPU: 1 PID: 361 Comm: insmod
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:__neigh_ifdown.isra.0+0x24b/0x370
RSP: 0018:ffff888012677908 EFLAGS: 00000202
...
Call Trace:
 <TASK>
 neigh_table_clear+0x94/0x2d0
 ndisc_cleanup+0x27/0x40 [ipv6]
 inet6_init+0x21c/0x2cb [ipv6]
 do_one_initcall+0xd3/0x4d0
 do_init_module+0x1ae/0x670
...
Kernel panic - not syncing: Fatal exception

When ipv6 initialization fails, it will try to cleanup and calls:

neigh_table_clear()
  neigh_ifdown(tbl, NULL)
    pneigh_queue_purge(&tbl->proxy_queue, dev_net(dev == NULL))
    # dev_net(NULL) triggers null-ptr-deref.

Fix it by passing NULL to pneigh_queue_purge() in neigh_ifdown() if dev
is NULL, to make kernel not panic immediately.

Fixes: 66ba215cb5 ("neigh: fix possible DoS due to net iface start/stop loop")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Link: https://lore.kernel.org/r/20221101121552.21890-1-chenzhongjin@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-10 18:14:20 +01:00
c3edc6e808 net: fix UAF issue in nfqnl_nf_hook_drop() when ops_init() failed
[ Upstream commit d266935ac4 ]

When the ops_init() interface is invoked to initialize the net, but
ops->init() fails, data is released. However, the ptr pointer in
net->gen is invalid. In this case, when nfqnl_nf_hook_drop() is invoked
to release the net, invalid address access occurs.

The process is as follows:
setup_net()
	ops_init()
		data = kzalloc(...)   ---> alloc "data"
		net_assign_generic()  ---> assign "date" to ptr in net->gen
		...
		ops->init()           ---> failed
		...
		kfree(data);          ---> ptr in net->gen is invalid
	...
	ops_exit_list()
		...
		nfqnl_nf_hook_drop()
			*q = nfnl_queue_pernet(net) ---> q is invalid

The following is the Call Trace information:
BUG: KASAN: use-after-free in nfqnl_nf_hook_drop+0x264/0x280
Read of size 8 at addr ffff88810396b240 by task ip/15855
Call Trace:
<TASK>
dump_stack_lvl+0x8e/0xd1
print_report+0x155/0x454
kasan_report+0xba/0x1f0
nfqnl_nf_hook_drop+0x264/0x280
nf_queue_nf_hook_drop+0x8b/0x1b0
__nf_unregister_net_hook+0x1ae/0x5a0
nf_unregister_net_hooks+0xde/0x130
ops_exit_list+0xb0/0x170
setup_net+0x7ac/0xbd0
copy_net_ns+0x2e6/0x6b0
create_new_namespaces+0x382/0xa50
unshare_nsproxy_namespaces+0xa6/0x1c0
ksys_unshare+0x3a4/0x7e0
__x64_sys_unshare+0x2d/0x40
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
</TASK>

Allocated by task 15855:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
__kasan_kmalloc+0xa1/0xb0
__kmalloc+0x49/0xb0
ops_init+0xe7/0x410
setup_net+0x5aa/0xbd0
copy_net_ns+0x2e6/0x6b0
create_new_namespaces+0x382/0xa50
unshare_nsproxy_namespaces+0xa6/0x1c0
ksys_unshare+0x3a4/0x7e0
__x64_sys_unshare+0x2d/0x40
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0

Freed by task 15855:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x2a/0x40
____kasan_slab_free+0x155/0x1b0
slab_free_freelist_hook+0x11b/0x220
__kmem_cache_free+0xa4/0x360
ops_init+0xb9/0x410
setup_net+0x5aa/0xbd0
copy_net_ns+0x2e6/0x6b0
create_new_namespaces+0x382/0xa50
unshare_nsproxy_namespaces+0xa6/0x1c0
ksys_unshare+0x3a4/0x7e0
__x64_sys_unshare+0x2d/0x40
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0

Fixes: f875bae065 ("net: Automatically allocate per namespace data.")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-03 23:57:52 +09:00
43d5109296 udp: Update reuse->has_conns under reuseport_lock.
commit 69421bf984 upstream.

When we call connect() for a UDP socket in a reuseport group, we have
to update sk->sk_reuseport_cb->has_conns to 1.  Otherwise, the kernel
could select a unconnected socket wrongly for packets sent to the
connected socket.

However, the current way to set has_conns is illegal and possible to
trigger that problem.  reuseport_has_conns() changes has_conns under
rcu_read_lock(), which upgrades the RCU reader to the updater.  Then,
it must do the update under the updater's lock, reuseport_lock, but
it doesn't for now.

For this reason, there is a race below where we fail to set has_conns
resulting in the wrong socket selection.  To avoid the race, let's split
the reader and updater with proper locking.

 cpu1                               cpu2
+----+                             +----+

__ip[46]_datagram_connect()        reuseport_grow()
.                                  .
|- reuseport_has_conns(sk, true)   |- more_reuse = __reuseport_alloc(more_socks_size)
|  .                               |
|  |- rcu_read_lock()
|  |- reuse = rcu_dereference(sk->sk_reuseport_cb)
|  |
|  |                               |  /* reuse->has_conns == 0 here */
|  |                               |- more_reuse->has_conns = reuse->has_conns
|  |- reuse->has_conns = 1         |  /* more_reuse->has_conns SHOULD BE 1 HERE */
|  |                               |
|  |                               |- rcu_assign_pointer(reuse->socks[i]->sk_reuseport_cb,
|  |                               |                     more_reuse)
|  `- rcu_read_unlock()            `- kfree_rcu(reuse, rcu)
|
|- sk->sk_state = TCP_ESTABLISHED

Note the likely(reuse) in reuseport_has_conns_set() is always true,
but we put the test there for ease of review.  [0]

For the record, usually, sk_reuseport_cb is changed under lock_sock().
The only exception is reuseport_grow() & TCP reqsk migration case.

  1) shutdown() TCP listener, which is moved into the latter part of
     reuse->socks[] to migrate reqsk.

  2) New listen() overflows reuse->socks[] and call reuseport_grow().

  3) reuse->max_socks overflows u16 with the new listener.

  4) reuseport_grow() pops the old shutdown()ed listener from the array
     and update its sk->sk_reuseport_cb as NULL without lock_sock().

shutdown()ed TCP sk->sk_reuseport_cb can be changed without lock_sock(),
but, reuseport_has_conns_set() is called only for UDP under lock_sock(),
so likely(reuse) never be false in reuseport_has_conns_set().

[0]: https://lore.kernel.org/netdev/CANn89iLja=eQHbsM_Ta2sQF0tOGU8vAGrh_izRuuHjuO1ouUag@mail.gmail.com/

Fixes: acdcecc612 ("udp: correct reuseport selection with connected sockets")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20221014182625.89913-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-30 09:41:19 +01:00
65029aaedd net: If sock is dead don't access sock's sk_wq in sk_stream_wait_memory
[ Upstream commit 3f8ef65af9 ]

Fixes the below NULL pointer dereference:

  [...]
  [   14.471200] Call Trace:
  [   14.471562]  <TASK>
  [   14.471882]  lock_acquire+0x245/0x2e0
  [   14.472416]  ? remove_wait_queue+0x12/0x50
  [   14.473014]  ? _raw_spin_lock_irqsave+0x17/0x50
  [   14.473681]  _raw_spin_lock_irqsave+0x3d/0x50
  [   14.474318]  ? remove_wait_queue+0x12/0x50
  [   14.474907]  remove_wait_queue+0x12/0x50
  [   14.475480]  sk_stream_wait_memory+0x20d/0x340
  [   14.476127]  ? do_wait_intr_irq+0x80/0x80
  [   14.476704]  do_tcp_sendpages+0x287/0x600
  [   14.477283]  tcp_bpf_push+0xab/0x260
  [   14.477817]  tcp_bpf_sendmsg_redir+0x297/0x500
  [   14.478461]  ? __local_bh_enable_ip+0x77/0xe0
  [   14.479096]  tcp_bpf_send_verdict+0x105/0x470
  [   14.479729]  tcp_bpf_sendmsg+0x318/0x4f0
  [   14.480311]  sock_sendmsg+0x2d/0x40
  [   14.480822]  ____sys_sendmsg+0x1b4/0x1c0
  [   14.481390]  ? copy_msghdr_from_user+0x62/0x80
  [   14.482048]  ___sys_sendmsg+0x78/0xb0
  [   14.482580]  ? vmf_insert_pfn_prot+0x91/0x150
  [   14.483215]  ? __do_fault+0x2a/0x1a0
  [   14.483738]  ? do_fault+0x15e/0x5d0
  [   14.484246]  ? __handle_mm_fault+0x56b/0x1040
  [   14.484874]  ? lock_is_held_type+0xdf/0x130
  [   14.485474]  ? find_held_lock+0x2d/0x90
  [   14.486046]  ? __sys_sendmsg+0x41/0x70
  [   14.486587]  __sys_sendmsg+0x41/0x70
  [   14.487105]  ? intel_pmu_drain_pebs_core+0x350/0x350
  [   14.487822]  do_syscall_64+0x34/0x80
  [   14.488345]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
  [...]

The test scenario has the following flow:

thread1                               thread2
-----------                           ---------------
 tcp_bpf_sendmsg
  tcp_bpf_send_verdict
   tcp_bpf_sendmsg_redir              sock_close
    tcp_bpf_push_locked                 __sock_release
     tcp_bpf_push                         //inet_release
      do_tcp_sendpages                    sock->ops->release
       sk_stream_wait_memory          	   // tcp_close
          sk_wait_event                      sk->sk_prot->close
           release_sock(__sk);
            ***
                                                lock_sock(sk);
                                                  __tcp_close
                                                    sock_orphan(sk)
                                                      sk->sk_wq  = NULL
                                                release_sock
            ****
           lock_sock(__sk);
          remove_wait_queue(sk_sleep(sk), &wait);
             sk_sleep(sk)
             //NULL pointer dereference
             &rcu_dereference_raw(sk->sk_wq)->wait

While waiting for memory in thread1, the socket is released with its wait
queue because thread2 has closed it. This caused by tcp_bpf_send_verdict
didn't increase the f_count of psock->sk_redir->sk_socket->file in thread1.

We should check if SOCK_DEAD flag is set on wakeup in sk_stream_wait_memory
before accessing the wait queue.

Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Liu Jian <liujian56@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/bpf/20220823133755.314697-2-liujian56@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 13:25:47 +02:00
aa400ccadf net: socket: remove register_gifconf
[ Upstream commit b0e99d0377 ]

Since dynamic registration of the gifconf() helper is only used for
IPv4, and this can not be in a loadable module, this can be simplified
noticeably by turning it into a direct function call as a preparation
for cleaning up the compat handling.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 5641c751fe ("net: enetc: deny offload of tc-based TSN features on VF interfaces")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-28 11:10:35 +02:00
d298fc2eef net: core: fix flow symmetric hash
[ Upstream commit 64ae13ed47 ]

__flow_hash_consistentify() wrongly swaps ipv4 addresses in few cases.
This function is indirectly used by __skb_get_hash_symmetric(), which is
used to fanout packets in AF_PACKET.
Intrusion detection systems may be impacted by this issue.

__flow_hash_consistentify() computes the addresses difference then swaps
them if the difference is negative. In few cases src - dst and dst - src
are both negative.

The following snippet mimics __flow_hash_consistentify():

```
 #include <stdio.h>
 #include <stdint.h>

 int main(int argc, char** argv) {

     int diffs_d, diffd_s;
     uint32_t dst  = 0xb225a8c0; /* 178.37.168.192 --> 192.168.37.178 */
     uint32_t src  = 0x3225a8c0; /*  50.37.168.192 --> 192.168.37.50  */
     uint32_t dst2 = 0x3325a8c0; /*  51.37.168.192 --> 192.168.37.51  */

     diffs_d = src - dst;
     diffd_s = dst - src;

     printf("src:%08x dst:%08x, diff(s-d)=%d(0x%x) diff(d-s)=%d(0x%x)\n",
             src, dst, diffs_d, diffs_d, diffd_s, diffd_s);

     diffs_d = src - dst2;
     diffd_s = dst2 - src;

     printf("src:%08x dst:%08x, diff(s-d)=%d(0x%x) diff(d-s)=%d(0x%x)\n",
             src, dst2, diffs_d, diffs_d, diffd_s, diffd_s);

     return 0;
 }
```

Results:

src:3225a8c0 dst:b225a8c0, \
    diff(s-d)=-2147483648(0x80000000) \
    diff(d-s)=-2147483648(0x80000000)

src:3225a8c0 dst:3325a8c0, \
    diff(s-d)=-16777216(0xff000000) \
    diff(d-s)=16777216(0x1000000)

In the first case the addresses differences are always < 0, therefore
__flow_hash_consistentify() always swaps, thus dst->src and src->dst
packets have differents hashes.

Fixes: c3f8324188 ("net: Add full IPv6 addresses to flow_keys")
Signed-off-by: Ludovic Cintrat <ludovic.cintrat@gatewatcher.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-28 11:10:30 +02:00
e90001e1dd net: let flow have same hash in two directions
[ Upstream commit 1e60cebf82 ]

using same source and destination ip/port for flow hash calculation
within the two directions.

Signed-off-by: zhang kai <zhangkaiheb@126.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 64ae13ed47 ("net: core: fix flow symmetric hash")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-28 11:10:30 +02:00
9d040a629e net/core/skbuff: Check the return value of skb_copy_bits()
[ Upstream commit c624c58e08 ]

skb_copy_bits() could fail, which requires a check on the return
value.

Signed-off-by: Li Zhong <floridsleeves@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-15 11:32:03 +02:00
bdc786d737 net: neigh: don't call kfree_skb() under spin_lock_irqsave()
commit d5485d9dd2 upstream.

It is not allowed to call kfree_skb() from hardware interrupt
context or with interrupts being disabled. So add all skb to
a tmp list, then free them after spin_unlock_irqrestore() at
once.

Fixes: 66ba215cb5 ("neigh: fix possible DoS due to net iface start/stop loop")
Suggested-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05 10:28:59 +02:00
c35adafe42 neigh: fix possible DoS due to net iface start/stop loop
[ Upstream commit 66ba215cb5 ]

Normal processing of ARP request (usually this is Ethernet broadcast
packet) coming to the host is looking like the following:
* the packet comes to arp_process() call and is passed through routing
  procedure
* the request is put into the queue using pneigh_enqueue() if
  corresponding ARP record is not local (common case for container
  records on the host)
* the request is processed by timer (within 80 jiffies by default) and
  ARP reply is sent from the same arp_process() using
  NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED condition (flag is set inside
  pneigh_enqueue())

And here the problem comes. Linux kernel calls pneigh_queue_purge()
which destroys the whole queue of ARP requests on ANY network interface
start/stop event through __neigh_ifdown().

This is actually not a problem within the original world as network
interface start/stop was accessible to the host 'root' only, which
could do more destructive things. But the world is changed and there
are Linux containers available. Here container 'root' has an access
to this API and could be considered as untrusted user in the hosting
(container's) world.

Thus there is an attack vector to other containers on node when
container's root will endlessly start/stop interfaces. We have observed
similar situation on a real production node when docker container was
doing such activity and thus other containers on the node become not
accessible.

The patch proposed doing very simple thing. It drops only packets from
the same namespace in the pneigh_queue_purge() where network interface
state change is detected. This is enough to prevent the problem for the
whole node preserving original semantics of the code.

v2:
	- do del_timer_sync() if queue is empty after pneigh_queue_purge()
v3:
	- rebase to net tree

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@kernel.org>
Cc: Yajun Deng <yajun.deng@linux.dev>
Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Cc: Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: kernel@openvz.org
Cc: devel@openvz.org
Investigated-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-05 10:28:57 +02:00
6204bf78b2 bpf: Don't redirect packets with invalid pkt_len
commit fd18942244 upstream.

Syzbot found an issue [1]: fq_codel_drop() try to drop a flow whitout any
skbs, that is, the flow->head is null.
The root cause, as the [2] says, is because that bpf_prog_test_run_skb()
run a bpf prog which redirects empty skbs.
So we should determine whether the length of the packet modified by bpf
prog or others like bpf_prog_test is valid before forwarding it directly.

LINK: [1] https://syzkaller.appspot.com/bug?id=0b84da80c2917757915afa89f7738a9d16ec96c5
LINK: [2] https://www.spinics.net/lists/netdev/msg777503.html

Reported-by: syzbot+7a12909485b94426aceb@syzkaller.appspotmail.com
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220715115559.139691-1-shaozhengchao@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05 10:28:56 +02:00
61cc798591 net: fix refcount bug in sk_psock_get (2)
commit 2a0133723f upstream.

Syzkaller reports refcount bug as follows:
------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 1 PID: 3605 at lib/refcount.c:19 refcount_warn_saturate+0xf4/0x1e0 lib/refcount.c:19
Modules linked in:
CPU: 1 PID: 3605 Comm: syz-executor208 Not tainted 5.18.0-syzkaller-03023-g7e062cda7d90 #0
 <TASK>
 __refcount_add_not_zero include/linux/refcount.h:163 [inline]
 __refcount_inc_not_zero include/linux/refcount.h:227 [inline]
 refcount_inc_not_zero include/linux/refcount.h:245 [inline]
 sk_psock_get+0x3bc/0x410 include/linux/skmsg.h:439
 tls_data_ready+0x6d/0x1b0 net/tls/tls_sw.c:2091
 tcp_data_ready+0x106/0x520 net/ipv4/tcp_input.c:4983
 tcp_data_queue+0x25f2/0x4c90 net/ipv4/tcp_input.c:5057
 tcp_rcv_state_process+0x1774/0x4e80 net/ipv4/tcp_input.c:6659
 tcp_v4_do_rcv+0x339/0x980 net/ipv4/tcp_ipv4.c:1682
 sk_backlog_rcv include/net/sock.h:1061 [inline]
 __release_sock+0x134/0x3b0 net/core/sock.c:2849
 release_sock+0x54/0x1b0 net/core/sock.c:3404
 inet_shutdown+0x1e0/0x430 net/ipv4/af_inet.c:909
 __sys_shutdown_sock net/socket.c:2331 [inline]
 __sys_shutdown_sock net/socket.c:2325 [inline]
 __sys_shutdown+0xf1/0x1b0 net/socket.c:2343
 __do_sys_shutdown net/socket.c:2351 [inline]
 __se_sys_shutdown net/socket.c:2349 [inline]
 __x64_sys_shutdown+0x50/0x70 net/socket.c:2349
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
 </TASK>

During SMC fallback process in connect syscall, kernel will
replaces TCP with SMC. In order to forward wakeup
smc socket waitqueue after fallback, kernel will sets
clcsk->sk_user_data to origin smc socket in
smc_fback_replace_callbacks().

Later, in shutdown syscall, kernel will calls
sk_psock_get(), which treats the clcsk->sk_user_data
as psock type, triggering the refcnt warning.

So, the root cause is that smc and psock, both will use
sk_user_data field. So they will mismatch this field
easily.

This patch solves it by using another bit(defined as
SK_USER_DATA_PSOCK) in PTRMASK, to mark whether
sk_user_data points to a psock object or not.
This patch depends on a PTRMASK introduced in commit f1ff5ce2cd
("net, sk_msg: Clear sk_user_data pointer on clone if tagged").

For there will possibly be more flags in the sk_user_data field,
this patch also refactor sk_user_data flags code to be more generic
to improve its maintainability.

Reported-and-tested-by: syzbot+5f26f85569bd179c18ce@syzkaller.appspotmail.com
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05 10:28:56 +02:00
c3bda708e9 net: Fix a data-race around netdev_budget_usecs.
[ Upstream commit fa45d484c5 ]

While reading netdev_budget_usecs, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.

Fixes: 7acf8a1e8a ("Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:15:20 +02:00
12a34d7f04 net: Fix a data-race around netdev_budget.
[ Upstream commit 2e0c42374e ]

While reading netdev_budget, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.

Fixes: 51b0bdedb8 ("[NET]: Separate two usages of netdev_max_backlog.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:15:20 +02:00
410c88314c net: Fix a data-race around sysctl_net_busy_read.
[ Upstream commit e59ef36f07 ]

While reading sysctl_net_busy_read, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.

Fixes: 2d48d67fa8 ("net: poll/select low latency socket support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:15:20 +02:00
8db070463e net: Fix a data-race around sysctl_tstamp_allow_data.
[ Upstream commit d2154b0afa ]

While reading sysctl_tstamp_allow_data, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its reader.

Fixes: b245be1f4d ("net-timestamp: no-payload only sysctl")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:15:20 +02:00
ed48223f87 net: Fix data-races around sysctl_optmem_max.
[ Upstream commit 7de6d09f51 ]

While reading sysctl_optmem_max, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:15:20 +02:00
27e8ade792 bpf: Folding omem_charge() into sk_storage_charge()
[ Upstream commit 9e838b02b0 ]

sk_storage_charge() is the only user of omem_charge().
This patch simplifies it by folding omem_charge() into
sk_storage_charge().

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20201112211301.2586255-1-kafai@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:15:20 +02:00
e73009ebc1 net: Fix data-races around netdev_tstamp_prequeue.
[ Upstream commit 61adf447e3 ]

While reading netdev_tstamp_prequeue, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 3b098e2d7c ("net: Consistent skb timestamping")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:15:19 +02:00
3850060352 net: Fix data-races around netdev_max_backlog.
[ Upstream commit 5dcd08cd19 ]

While reading netdev_max_backlog, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

While at it, we remove the unnecessary spaces in the doc.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:15:19 +02:00
b498a1b017 net: Fix data-races around weight_p and dev_weight_[rt]x_bias.
[ Upstream commit bf955b5ab8 ]

While reading weight_p, it can be changed concurrently.  Thus, we need
to add READ_ONCE() to its reader.

Also, dev_[rt]x_weight can be read/written at the same time.  So, we
need to use READ_ONCE() and WRITE_ONCE() for its access.  Moreover, to
use the same weight_p while changing dev_[rt]x_weight, we add a mutex
in proc_do_dev_weight().

Fixes: 3d48b53fb2 ("net: dev_weight: TX/RX orthogonality")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:15:19 +02:00
fb442c72db net: Fix data-races around sysctl_[rw]mem_(max|default).
[ Upstream commit 1227c1771d ]

While reading sysctl_[rw]mem_(max|default), they can be changed
concurrently.  Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:15:19 +02:00
0e28678a77 devlink: Fix use-after-free after a failed reload
commit 6b4db2e528 upstream.

After a failed devlink reload, devlink parameters are still registered,
which means user space can set and get their values. In the case of the
mlxsw "acl_region_rehash_interval" parameter, these operations will
trigger a use-after-free [1].

Fix this by rejecting set and get operations while in the failed state.
Return the "-EOPNOTSUPP" error code which does not abort the parameters
dump, but instead causes it to skip over the problematic parameter.

Another possible fix is to perform these checks in the mlxsw parameter
callbacks, but other drivers might be affected by the same problem and I
am not aware of scenarios where these stricter checks will cause a
regression.

[1]
mlxsw_spectrum3 0000:00:10.0: Port 125: Failed to register netdev
mlxsw_spectrum3 0000:00:10.0: Failed to create ports

==================================================================
BUG: KASAN: use-after-free in mlxsw_sp_acl_tcam_vregion_rehash_intrvl_get+0xbd/0xd0 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c:904
Read of size 4 at addr ffff8880099dcfd8 by task kworker/u4:4/777

CPU: 1 PID: 777 Comm: kworker/u4:4 Not tainted 5.19.0-rc7-custom-126601-gfe26f28c586d #1
Hardware name: QEMU MSN4700, BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x92/0xbd lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:313 [inline]
 print_report.cold+0x5e/0x5cf mm/kasan/report.c:429
 kasan_report+0xb9/0xf0 mm/kasan/report.c:491
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 mlxsw_sp_acl_tcam_vregion_rehash_intrvl_get+0xbd/0xd0 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c:904
 mlxsw_sp_acl_region_rehash_intrvl_get+0x49/0x60 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c:1106
 mlxsw_sp_params_acl_region_rehash_intrvl_get+0x33/0x80 drivers/net/ethernet/mellanox/mlxsw/spectrum.c:3854
 devlink_param_get net/core/devlink.c:4981 [inline]
 devlink_nl_param_fill+0x238/0x12d0 net/core/devlink.c:5089
 devlink_param_notify+0xe5/0x230 net/core/devlink.c:5168
 devlink_ns_change_notify net/core/devlink.c:4417 [inline]
 devlink_ns_change_notify net/core/devlink.c:4396 [inline]
 devlink_reload+0x15f/0x700 net/core/devlink.c:4507
 devlink_pernet_pre_exit+0x112/0x1d0 net/core/devlink.c:12272
 ops_pre_exit_list net/core/net_namespace.c:152 [inline]
 cleanup_net+0x494/0xc00 net/core/net_namespace.c:582
 process_one_work+0x9fc/0x1710 kernel/workqueue.c:2289
 worker_thread+0x675/0x10b0 kernel/workqueue.c:2436
 kthread+0x30c/0x3d0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0000267700 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x99dc
flags: 0x100000000000000(node=0|zone=1)
raw: 0100000000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880099dce80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880099dcf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880099dcf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                    ^
 ffff8880099dd000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880099dd080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Fixes: 98bbf70c1c ("mlxsw: spectrum: add "acl_region_rehash_interval" devlink param")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:37:57 +02:00
b9d9cf88c8 bpf: Check the validity of max_rdwr_access for sock local storage map iterator
commit 52bd05eb7c upstream.

The value of sock local storage map is writable in map iterator, so check
max_rdwr_access instead of max_rdonly_access.

Fixes: 5ce6e77c7e ("bpf: Implement bpf iterator for sock local storage map")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220810080538.1845898-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:37:55 +02:00
f7d844df5e bpf: Acquire map uref in .init_seq_private for sock{map,hash} iterator
commit f0d2b2716d upstream.

sock_map_iter_attach_target() acquires a map uref, and the uref may be
released before or in the middle of iterating map elements. For example,
the uref could be released in sock_map_iter_detach_target() as part of
bpf_link_release(), or could be released in bpf_map_put_with_uref() as
part of bpf_map_release().

Fixing it by acquiring an extra map uref in .init_seq_private and
releasing it in .fini_seq_private.

Fixes: 0365351524 ("net: Allow iterating sockmap and sockhash")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220810080538.1845898-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:37:55 +02:00
d7ad7e65aa bpf: Acquire map uref in .init_seq_private for sock local storage map iterator
commit 3c5f6e698b upstream.

bpf_iter_attach_map() acquires a map uref, and the uref may be released
before or in the middle of iterating map elements. For example, the uref
could be released in bpf_iter_detach_map() as part of
bpf_link_release(), or could be released in bpf_map_put_with_uref() as
part of bpf_map_release().

So acquiring an extra map uref in bpf_iter_init_sk_storage_map() and
releasing it in bpf_iter_fini_sk_storage_map().

Fixes: 5ce6e77c7e ("bpf: Implement bpf iterator for sock local storage map")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220810080538.1845898-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:37:55 +02:00
6d3fad2b44 bpf: Add PROG_TEST_RUN support for sk_lookup programs
commit 7c32e8f8bc upstream.

Allow to pass sk_lookup programs to PROG_TEST_RUN. User space
provides the full bpf_sk_lookup struct as context. Since the
context includes a socket pointer that can't be exposed
to user space we define that PROG_TEST_RUN returns the cookie
of the selected socket or zero in place of the socket pointer.

We don't support testing programs that select a reuseport socket,
since this would mean running another (unrelated) BPF program
from the sk_lookup test handler.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210303101816.36774-3-lmb@cloudflare.com
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-03 12:00:52 +02:00
ffc388f6f0 tcp: Fix data-races around sysctl knobs related to SYN option.
[ Upstream commit 3666f666e9 ]

While reading these knobs, they can be changed concurrently.
Thus, we need to add READ_ONCE() to their readers.

  - tcp_sack
  - tcp_window_scaling
  - tcp_timestamps

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-29 17:19:21 +02:00
dc1a78a2b2 tcp: Fix data-races around sysctl_tcp_syncookies.
[ Upstream commit f2e383b5bb ]

While reading sysctl_tcp_syncookies, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-29 17:19:16 +02:00
4f900c37f1 net: inline rollback_registered_many()
commit 0cbe1e57a7 upstream.

Similar to the change for rollback_registered() -
rollback_registered_many() was a part of unregister_netdevice_many()
minus the net_set_todo(), which is no longer needed.

Functionally this patch moves the list_empty() check back after:

	BUG_ON(dev_boot_phase);
	ASSERT_RTNL();

but I can't find any reason why that would be an issue.

Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29 17:19:09 +02:00
bf2f3d1970 net: move rollback_registered_many()
commit bcfe2f1a38 upstream.

Move rollback_registered_many() and add a temporary
forward declaration to make merging the code into
unregister_netdevice_many() easier to review.

No functional changes.

Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29 17:19:08 +02:00
672fac0a43 net: inline rollback_registered()
commit 037e56bd96 upstream.

rollback_registered() is a local helper, it's common for driver
code to call unregister_netdevice_queue(dev, NULL) when they
want to unregister netdevices under rtnl_lock. Inline
rollback_registered() and adjust the only remaining caller.

Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29 17:19:08 +02:00
b1158677d4 net: move net_set_todo inside rollback_registered()
commit 2014beea7e upstream.

Commit 93ee31f14f ("[NET]: Fix free_netdev on register_netdev
failure.") moved net_set_todo() outside of rollback_registered()
so that rollback_registered() can be used in the failure path of
register_netdevice() but without risking a double free.

Since commit cf124db566 ("net: Fix inconsistent teardown and
release of private netdev state."), however, we have a better
way of handling that condition, since destructors don't call
free_netdev() directly.

After the change in commit c269a24ce0 ("net: make free_netdev()
more lenient with unregistering devices") we can now move
net_set_todo() back.

Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29 17:19:08 +02:00
2e11856ec3 net: make sure devices go through netdev_wait_all_refs
commit 766b0515d5 upstream.

If register_netdevice() fails at the very last stage - the
notifier call - some subsystems may have already seen it and
grabbed a reference. struct net_device can't be freed right
away without calling netdev_wait_all_refs().

Now that we have a clean interface in form of dev->needs_free_netdev
and lenient free_netdev() we can undo what commit 93ee31f14f ("[NET]:
Fix free_netdev on register_netdev failure.") has done and complete
the unregistration path by bringing the net_set_todo() call back.

After registration fails user is still expected to explicitly
free the net_device, so make sure ->needs_free_netdev is cleared,
otherwise rolling back the registration will cause the old double
free for callers who release rtnl_lock before the free.

This also solves the problem of priv_destructor not being called
on notifier error.

net_set_todo() will be moved back into unregister_netdevice_queue()
in a follow up.

Reported-by: Hulk Robot <hulkci@huawei.com>
Reported-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29 17:19:08 +02:00
ed6964ff47 net: make free_netdev() more lenient with unregistering devices
commit c269a24ce0 upstream.

There are two flavors of handling netdev registration:
 - ones called without holding rtnl_lock: register_netdev() and
   unregister_netdev(); and
 - those called with rtnl_lock held: register_netdevice() and
   unregister_netdevice().

While the semantics of the former are pretty clear, the same can't
be said about the latter. The netdev_todo mechanism is utilized to
perform some of the device unregistering tasks and it hooks into
rtnl_unlock() so the locked variants can't actually finish the work.
In general free_netdev() does not mix well with locked calls. Most
drivers operating under rtnl_lock set dev->needs_free_netdev to true
and expect core to make the free_netdev() call some time later.

The part where this becomes most problematic is error paths. There is
no way to unwind the state cleanly after a call to register_netdevice(),
since unreg can't be performed fully without dropping locks.

Make free_netdev() more lenient, and defer the freeing if device
is being unregistered. This allows error paths to simply call
free_netdev() both after register_netdevice() failed, and after
a call to unregister_netdevice() but before dropping rtnl_lock.

Simplify the error paths which are currently doing gymnastics
around free_netdev() handling.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29 17:19:07 +02:00
2686f62fa7 docs: net: explain struct net_device lifetime
commit 2b446e650b upstream.

Explain the two basic flows of struct net_device's operation.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29 17:19:07 +02:00
2d4efc9a0e seg6: bpf: fix skb checksum in bpf_push_seg6_encap()
[ Upstream commit 4889fbd98d ]

Both helper functions bpf_lwt_seg6_action() and bpf_lwt_push_encap() use
the bpf_push_seg6_encap() to encapsulate the packet in an IPv6 with Segment
Routing Header (SRH) or insert an SRH between the IPv6 header and the
payload.
To achieve this result, such helper functions rely on bpf_push_seg6_encap()
which, in turn, leverages seg6_do_srh_{encap,inline}() to perform the
required operation (i.e. encap/inline).

This patch removes the initialization of the IPv6 header payload length
from bpf_push_seg6_encap(), as it is now handled properly by
seg6_do_srh_{encap,inline}() to prevent corruption of the skb checksum.

Fixes: fe94cc290f ("bpf: Add IPv6 Segment Routing helpers")
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-21 21:20:11 +02:00