linux/net
Alexey Kodanev b1cb59cf2e net: sysctl_net_core: check SNDBUF and RCVBUF for min length
sysctl has sysctl.net.core.rmem_*/wmem_* parameters which can be
set to incorrect values. Given that 'struct sk_buff' allocates from
rcvbuf, incorrectly set buffer length could result to memory
allocation failures. For example, set them as follows:

    # sysctl net.core.rmem_default=64
      net.core.wmem_default = 64
    # sysctl net.core.wmem_default=64
      net.core.wmem_default = 64
    # ping localhost -s 1024 -i 0 > /dev/null

This could result to the following failure:

skbuff: skb_over_panic: text:ffffffff81628db4 len:-32 put:-32
head:ffff88003a1cc200 data:ffff88003a1cc200 tail:0xffffffe0 end:0xc0 dev:<NULL>
kernel BUG at net/core/skbuff.c:102!
invalid opcode: 0000 [#1] SMP
...
task: ffff88003b7f5550 ti: ffff88003ae88000 task.ti: ffff88003ae88000
RIP: 0010:[<ffffffff8155fbd1>]  [<ffffffff8155fbd1>] skb_put+0xa1/0xb0
RSP: 0018:ffff88003ae8bc68  EFLAGS: 00010296
RAX: 000000000000008d RBX: 00000000ffffffe0 RCX: 0000000000000000
RDX: ffff88003fdcf598 RSI: ffff88003fdcd9c8 RDI: ffff88003fdcd9c8
RBP: ffff88003ae8bc88 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 00000000000002b2 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88003d3f7300 R15: ffff88000012a900
FS:  00007fa0e2b4a840(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000d0f7e0 CR3: 000000003b8fb000 CR4: 00000000000006f0
Stack:
 ffff88003a1cc200 00000000ffffffe0 00000000000000c0 ffffffff818cab1d
 ffff88003ae8bd68 ffffffff81628db4 ffff88003ae8bd48 ffff88003b7f5550
 ffff880031a09408 ffff88003b7f5550 ffff88000012aa48 ffff88000012ab00
Call Trace:
 [<ffffffff81628db4>] unix_stream_sendmsg+0x2c4/0x470
 [<ffffffff81556f56>] sock_write_iter+0x146/0x160
 [<ffffffff811d9612>] new_sync_write+0x92/0xd0
 [<ffffffff811d9cd6>] vfs_write+0xd6/0x180
 [<ffffffff811da499>] SyS_write+0x59/0xd0
 [<ffffffff81651532>] system_call_fastpath+0x12/0x17
Code: 00 00 48 89 44 24 10 8b 87 c8 00 00 00 48 89 44 24 08 48 8b 87 d8 00
      00 00 48 c7 c7 30 db 91 81 48 89 04 24 31 c0 e8 4f a8 0e 00 <0f> 0b
      eb fe 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 48 83
RIP  [<ffffffff8155fbd1>] skb_put+0xa1/0xb0
RSP <ffff88003ae8bc68>
Kernel panic - not syncing: Fatal exception

Moreover, the possible minimum is 1, so we can get another kernel panic:
...
BUG: unable to handle kernel paging request at ffff88013caee5c0
IP: [<ffffffff815604cf>] __alloc_skb+0x12f/0x1f0
...

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-11 21:25:13 -04:00
..
6lowpan net/6lowpan: Remove FSF address from GPL statement. 2014-12-05 12:43:04 +01:00
9p virtio/9p: verify device has config space 2015-01-21 16:28:45 +10:30
802
8021q vlan: advertise link netns via netlink 2015-01-23 17:51:15 -08:00
appletalk new helper: memcpy_from_msg() 2014-11-24 04:28:48 -05:00
atm put iov_iter into msghdr 2014-12-09 16:29:03 -05:00
ax25 new helper: memcpy_from_msg() 2014-11-24 04:28:48 -05:00
batman-adv batman-adv: Kconfig, Add missing DEBUG_FS dependency 2015-01-07 22:17:11 +01:00
bluetooth Bluetooth: Fix potential NULL dereference 2015-02-03 09:02:12 +01:00
bridge net: bridge: add compile-time assert for cb struct size 2015-03-03 14:07:04 -05:00
caif caif: fix a signedness bug in cfpkt_iterate() 2015-02-20 17:35:14 -05:00
can can: add missing initialisations in CAN related skbuffs 2015-03-09 10:22:24 +01:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2015-02-19 14:14:42 -08:00
core net: sysctl_net_core: check SNDBUF and RCVBUF for min length 2015-03-11 21:25:13 -04:00
dcb dcbnl : Disable software interrupts before taking dcb_lock 2014-11-16 14:50:52 -05:00
dccp net: introduce helper macro for_each_cmsghdr 2014-12-10 22:41:55 -05:00
decnet decnet: Fix obvious o/0 typo 2015-02-23 15:28:50 -05:00
dns_resolver
dsa net: dsa: Set valid phy interface type 2015-02-17 10:37:39 -08:00
ethernet net: Add Transparent Ethernet Bridging GRO support. 2015-01-02 15:46:41 -05:00
hsr net/hsr: Fix NULL pointer dereference and refcnt bugs when deleting a HSR interface. 2015-03-01 13:40:23 -05:00
ieee802154 netlink: make nlmsg_end() and genlmsg_end() void 2015-01-18 01:03:45 -05:00
ipv4 tcp: restore 1.5x per RTT limit to CUBIC cwnd growth in congestion avoidance 2015-03-11 16:51:51 -04:00
ipv6 ip: fix error queue empty skb handling 2015-03-08 23:01:54 -04:00
ipx switch ipxrtr_route_packet() from iovec to msghdr 2014-11-24 04:28:49 -05:00
irda TTY/Serial fixes for 4.0-rc3 2015-03-08 12:25:40 -07:00
iucv net: introduce helper macro for_each_cmsghdr 2014-12-10 22:41:55 -05:00
key new helper: memcpy_from_msg() 2014-11-24 04:28:48 -05:00
l2tp netlink: make nlmsg_end() and genlmsg_end() void 2015-01-18 01:03:45 -05:00
lapb lapb: move EXPORT_SYMBOL after functions. 2014-10-24 15:51:42 -04:00
llc net: llc: use correct size for sysctl timeout entries 2015-01-25 00:23:21 -08:00
mac80211 mac80211: Send EAPOL frames at lowest rate 2015-02-26 21:03:06 +01:00
mac802154 mac802154: fix kbuild test robot warning 2015-01-03 01:51:51 +01:00
mpls net: mark some potential candidates __read_mostly 2015-01-30 17:58:39 -08:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2015-03-05 21:51:07 -05:00
netlabel Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2015-02-11 20:25:11 -08:00
netlink rhashtable: remove indirection for grow/shrink decision functions 2015-02-27 16:06:02 -05:00
netrom new helper: memcpy_from_msg() 2014-11-24 04:28:48 -05:00
nfc NFC: nci: Move NFCEE discovery logic 2015-02-04 09:15:18 +01:00
openvswitch openvswitch: Fix serialization of non-masked set actions. 2015-03-03 14:38:57 -05:00
packet net: delete stale packet_mclist entries 2015-03-09 16:17:43 -04:00
phonet phonet netlink: allow multiple messages per skb in route dump 2015-01-19 16:20:17 -05:00
rds rds: rds_cong_queue_updates needs to defer the congestion update transmission 2015-02-11 14:35:44 -08:00
rfkill Last round of updates for net-next: 2015-02-04 14:57:45 -08:00
rose new helper: memcpy_from_msg() 2014-11-24 04:28:48 -05:00
rxrpc ip: fix error queue empty skb handling 2015-03-08 23:01:54 -04:00
sched net_sched: fix struct tc_u_hnode layout in u32 2015-03-09 23:44:31 -04:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-02-05 14:33:28 -08:00
sunrpc sunrpc: fix braino in ->poll() 2015-03-08 12:53:46 -07:00
switchdev Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2015-02-19 10:36:45 -08:00
tipc tipc: fix bug in link failover handling 2015-03-09 16:20:41 -04:00
unix net: remove sock_iocb 2015-01-28 23:15:07 -08:00
vmw_vsock vmci: propagate msghdr all way down to __qp_memcpy_to_queue() 2015-02-04 01:34:14 -05:00
wimax wimax: convert printk to pr_foo() 2014-10-07 20:28:44 -04:00
wireless cfg80211: calls nl80211_exit on error 2015-02-24 11:41:21 +01:00
x25 new helper: memcpy_from_msg() 2014-11-24 04:28:48 -05:00
xfrm netlink: make nlmsg_end() and genlmsg_end() void 2015-01-18 01:03:45 -05:00
compat.c net: compat: Ignore MSG_CMSG_COMPAT in compat_sys_{send, recv}msg 2015-02-23 17:22:05 -05:00
Kconfig kconfig: use bool instead of boolean for type definition attributes 2015-01-07 13:08:04 +01:00
Makefile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-16 15:53:03 -08:00
socket.c net: switch sockets to ->read_iter/->write_iter 2015-02-04 01:34:15 -05:00
sysctl_net.c