linux/net/rds
Cen Zhang (Microsoft) 167e54c703 rds: tcp: unregister sysctl before tearing down listen socket
rds_tcp_exit_net() frees the per-netns RDS TCP listen socket via
rds_tcp_kill_sock() before unregistering the per-netns sysctl table.  Since
rds_tcp_skbuf_handler() derives the netns from
rtn->rds_tcp_listen_sock->sk, a concurrent sysctl write can race with
netns teardown and dereference the freed socket/sk.

KASAN reports the race as:

  BUG: KASAN: slab-use-after-free in rds_tcp_skbuf_handler+0x2aa/0x2e0
  rds_tcp_skbuf_handler              net/rds/tcp.c:721
  proc_sys_call_handler              fs/proc/proc_sysctl.c
  vfs_write                          fs/read_write.c
  __x64_sys_pwrite64                 fs/read_write.c

Fix this by unregistering the RDS TCP sysctl table before calling
rds_tcp_kill_sock().  unregister_net_sysctl_table() prevents new sysctl
handlers from starting and waits for in-flight handlers to finish, so
the listen socket can then be released safely. The fix was tested
against the linked reproducer.

Fixes: 7f5611cbc4 ("rds: sysctl: rds_tcp_{rcv,snd}buf: avoid using current->nsproxy")
Reported-by: AutonomousCodeSecurity@microsoft.com
Link: https://lore.kernel.org/all/20260719203718.9680-1-blbllhy@gmail.com
Reviewed-by: Allison Henderson <achender@kernel.org>
Signed-off-by: Cen Zhang (Microsoft) <blbllhy@gmail.com>
Link: https://patch.msgid.link/20260719210357.10179-1-blbllhy@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23 09:15:20 -07:00
..
af_rds.c rds: convert to getsockopt_iter 2026-06-11 12:19:05 +02:00
bind.c net: Convert proto_ops bind() callbacks to use sockaddr_unsized 2025-11-04 19:10:32 -08:00
cong.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
connection.c rds: filter RDS_INFO_* getsockopt by caller's netns 2026-05-25 12:18:42 -07:00
ib_cm.c rds: Fix inet6_addr_lst NULL dereference when IPv6 is disabled 2026-07-21 12:15:13 -07:00
ib_frmr.c rds: ib: Increment i_fastreg_wrs before bailing out 2025-09-15 16:47:53 -07:00
ib_mr.h rds: ib: Remove unused extern definition 2025-09-08 18:16:49 -07:00
ib_rdma.c net/rds: Optimize rds_ib_laddr_check 2026-04-12 13:33:19 -07:00
ib_recv.c net/rds: Add per cp work queue 2026-01-13 12:27:03 +01:00
ib_ring.c
ib_send.c net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion 2026-06-09 18:32:54 -07:00
ib_stats.c
ib_sysctl.c net: rds: Remove the now superfluous sentinel elements from ctl_table array 2024-05-03 13:29:42 +01:00
ib.c rds: Fix inet6_addr_lst NULL dereference when IPv6 is disabled 2026-07-21 12:15:13 -07:00
ib.h net/rds: Optimize rds_ib_laddr_check 2026-04-12 13:33:19 -07:00
info.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2026-06-11 14:33:35 -07:00
info.h rds: convert to getsockopt_iter 2026-06-11 12:19:05 +02:00
Kconfig net: rds: add option for GCOV profiling 2024-08-09 13:18:46 +01:00
loop.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
loop.h
Makefile net: rds: add option for GCOV profiling 2024-08-09 13:18:46 +01:00
message.c net/rds: reset op_nents when zerocopy page pin fails 2026-05-11 17:20:02 -07:00
page.c rds: Use nested-BH locking for rds_page_remainder 2025-05-15 15:23:31 +02:00
rdma_transport.c
rdma_transport.h
rdma.c net: rds: fix MR cleanup on copy error 2026-04-23 12:18:08 -07:00
rds_single_path.h
rds.h net/rds: Trigger rds_send_ping() more than once 2026-02-04 20:46:39 -08:00
recv.c rds: drop incoming messages that cross network namespace boundaries 2026-07-21 11:12:51 +02:00
send.c net: rds: check cmsg_len before reading rds_rdma_args in size pass 2026-06-18 18:25:28 -07:00
stats.c net/rds: Use the first lane until RDS_EXTHDR_NPATHS arrives 2026-02-04 20:46:39 -08:00
sysctl.c net: rds: Remove the now superfluous sentinel elements from ctl_table array 2024-05-03 13:29:42 +01:00
tcp_connect.c net/rds: rds_tcp_conn_path_shutdown must not discard messages 2026-02-04 20:46:38 -08:00
tcp_listen.c rds: tcp_listen: fix typos in comments 2026-05-14 17:11:26 -07:00
tcp_recv.c net/rds: use special gfp_t format specifier 2026-05-28 21:04:53 -07:00
tcp_send.c net/rds: rds_tcp_conn_path_shutdown must not discard messages 2026-02-04 20:46:38 -08:00
tcp_stats.c
tcp.c rds: tcp: unregister sysctl before tearing down listen socket 2026-07-23 09:15:20 -07:00
tcp.h net/rds: Trigger rds_send_ping() more than once 2026-02-04 20:46:39 -08:00
threads.c net/rds: Add per cp work queue 2026-01-13 12:27:03 +01:00
transport.c