linux/net/mptcp
Paolo Abeni 0a3f4f1f9c mptcp: fix UaF in listener shutdown
As reported by Christoph after having refactored the passive
socket initialization, the mptcp listener shutdown path is prone
to an UaF issue.

  BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x73/0xe0
  Write of size 4 at addr ffff88810cb23098 by task syz-executor731/1266

  CPU: 1 PID: 1266 Comm: syz-executor731 Not tainted 6.2.0-rc59af4eaa31c1f6c00c8f1e448ed99a45c66340dd5 #6
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x6e/0x91
   print_report+0x16a/0x46f
   kasan_report+0xad/0x130
   kasan_check_range+0x14a/0x1a0
   _raw_spin_lock_bh+0x73/0xe0
   subflow_error_report+0x6d/0x110
   sk_error_report+0x3b/0x190
   tcp_disconnect+0x138c/0x1aa0
   inet_child_forget+0x6f/0x2e0
   inet_csk_listen_stop+0x209/0x1060
   __mptcp_close_ssk+0x52d/0x610
   mptcp_destroy_common+0x165/0x640
   mptcp_destroy+0x13/0x80
   __mptcp_destroy_sock+0xe7/0x270
   __mptcp_close+0x70e/0x9b0
   mptcp_close+0x2b/0x150
   inet_release+0xe9/0x1f0
   __sock_release+0xd2/0x280
   sock_close+0x15/0x20
   __fput+0x252/0xa20
   task_work_run+0x169/0x250
   exit_to_user_mode_prepare+0x113/0x120
   syscall_exit_to_user_mode+0x1d/0x40
   do_syscall_64+0x48/0x90
   entry_SYSCALL_64_after_hwframe+0x72/0xdc

The msk grace period can legitly expire in between the last
reference count dropped in mptcp_subflow_queue_clean() and
the later eventual access in inet_csk_listen_stop()

After the previous patch we don't need anymore special-casing
msk listener socket cleanup: the mptcp worker will process each
of the unaccepted msk sockets.

Just drop the now unnecessary code.

Please note this commit depends on the two parent ones:

  mptcp: refactor passive socket initialization
  mptcp: use the workqueue to destroy unaccepted sockets

Fixes: 6aeed90450 ("mptcp: fix race on unaccepted mptcp sockets")
Cc: stable@vger.kernel.org
Reported-and-tested-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/346
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-10 21:42:56 -08:00
..
bpf.c bpf: Add bpf_skc_to_mptcp_sock_proto 2022-05-20 15:29:00 -07:00
crypto_test.c mptcp: move crypto test to KUNIT 2020-06-26 16:21:39 -07:00
crypto.c kunit: mptcp: adhere to KUNIT formatting standard 2021-04-16 17:10:40 -07:00
ctrl.c mptcp: Add a per-namespace sysctl to set the default path manager type 2022-04-29 17:25:14 -07:00
diag.c
fastopen.c mptcp: add subflow_v(4,6)_send_synack() 2022-11-29 20:24:25 -08:00
Kconfig kunit: mptcp: adhere to KUNIT formatting standard 2021-04-16 17:10:40 -07:00
Makefile mptcp: implement delayed seq generation for passive fastopen 2022-11-29 20:24:25 -08:00
mib.c mptcp: add more offered MIBs counter 2022-05-05 19:00:16 -07:00
mib.h mptcp: add more offered MIBs counter 2022-05-05 19:00:16 -07:00
mptcp_diag.c tcp: Access &tcp_hashinfo via net. 2022-09-20 10:21:49 -07:00
options.c mptcp: use local variable ssk in write_options 2023-01-09 07:30:49 +00:00
pm_netlink.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-02-09 12:25:40 -08:00
pm_userspace.c mptcp: userspace pm: use a single point of exit 2023-01-26 13:33:30 +01:00
pm.c mptcp: netlink: respect v4/v6-only sockets 2023-01-13 21:55:45 -08:00
protocol.c mptcp: fix UaF in listener shutdown 2023-03-10 21:42:56 -08:00
protocol.h mptcp: fix UaF in listener shutdown 2023-03-10 21:42:56 -08:00
sockopt.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-02-09 12:25:40 -08:00
subflow.c mptcp: fix UaF in listener shutdown 2023-03-10 21:42:56 -08:00
syncookies.c mptcp: don't return sockets in foreign netns 2021-09-24 10:51:36 +01:00
token_test.c mptcp: init sk->sk_prot in build_msk() 2023-01-09 07:30:50 +00:00
token.c mptcp: add statistics for mptcp socket in use 2023-01-09 07:30:50 +00:00