Eric Dumazet 05c9e3fc93 netlink: annotate lockless accesses to nlk->max_recvmsg_len ... commit a1865f2e7d upstream. syzbot reported a data-race in data-race in netlink_recvmsg() [1] Indeed, netlink_recvmsg() can be run concurrently, and netlink_dump() also needs protection. [1] BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg read to 0xffff888141840b38 of 8 bytes by task 23057 on cpu 0: netlink_recvmsg+0xea/0x730 net/netlink/af_netlink.c:1988 sock_recvmsg_nosec net/socket.c:1017 [inline] sock_recvmsg net/socket.c:1038 [inline] __sys_recvfrom+0x1ee/0x2e0 net/socket.c:2194 __do_sys_recvfrom net/socket.c:2212 [inline] __se_sys_recvfrom net/socket.c:2208 [inline] __x64_sys_recvfrom+0x78/0x90 net/socket.c:2208 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd write to 0xffff888141840b38 of 8 bytes by task 23037 on cpu 1: netlink_recvmsg+0x114/0x730 net/netlink/af_netlink.c:1989 sock_recvmsg_nosec net/socket.c:1017 [inline] sock_recvmsg net/socket.c:1038 [inline] ____sys_recvmsg+0x156/0x310 net/socket.c:2720 ___sys_recvmsg net/socket.c:2762 [inline] do_recvmmsg+0x2e5/0x710 net/socket.c:2856 __sys_recvmmsg net/socket.c:2935 [inline] __do_sys_recvmmsg net/socket.c:2958 [inline] __se_sys_recvmmsg net/socket.c:2951 [inline] __x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2951 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x0000000000000000 -> 0x0000000000001000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 23037 Comm: syz-executor.2 Not tainted 6.3.0-rc4-syzkaller-00195-g5a57b48fdfcb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Fixes: 9063e21fb0 ("netlink: autosize skb lengthes") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230403214643.768555-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: yenchia.chen <yenchia.chen@mediatek.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2024-05-25 16:19:06 +02:00
..
Kconfig	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
Makefile	netlink: add infrastructure to expose policies to userspace	2020-04-30 17:51:42 -07:00
af_netlink.c	netlink: annotate lockless accesses to nlk->max_recvmsg_len	2024-05-25 16:19:06 +02:00
af_netlink.h	…
diag.c	netlink: Add __sock_i_ino() for __netlink_diag_dump().	2023-07-27 08:43:43 +02:00
genetlink.c	drop_monitor: Require 'CAP_SYS_ADMIN' when joining "events" group	2023-12-13 18:27:06 +01:00
policy.c	net: genl: fix error path memory leak in policy dumping	2022-08-25 11:38:07 +02:00