syzbot


KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv (7)

Status: moderation: reported on 2026/01/05 19:04
Subsystems: tipc
[Documentation on labels]
Reported-by: syzbot+c2554c7622dd36deb461@syzkaller.appspotmail.com
First crash: 57d, last: 23d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
67c9b4f3-f818-4787-8836-8d349b1b0c3b assessment-kcsan Benign: ✅  Confident: ✅  KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv (7) 2026/01/15 20:07 2026/01/15 20:07 2026/01/15 20:14 a9d6a79219801d2130df3b1a792c57f0e5428e9f
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv tipc 6 1 972d 972d 0/29 auto-obsoleted due to no activity on 2023/08/04 11:38
upstream KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv (2) tipc 6 1 613d 613d 0/29 auto-obsoleted due to no activity on 2024/07/29 09:10
upstream KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv (6) tipc 6 1 170d 170d 0/29 auto-obsoleted due to no activity on 2025/11/04 10:56
upstream KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv (4) tipc 6 3 319d 268d 0/29 auto-obsoleted due to no activity on 2025/06/18 09:51
upstream KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv (3) tipc 6 1 568d 568d 0/29 auto-obsoleted due to no activity on 2024/09/11 16:33
upstream KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv (5) tipc 6 1 239d 239d 0/29 auto-obsoleted due to no activity on 2025/08/27 14:35

Sample crash report:
==================================================================
BUG: KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv

read-write to 0xffff888103b958e6 of 2 bytes by task 9053 on cpu 1:
 tipc_sk_conn_proto_rcv net/tipc/socket.c:1367 [inline]
 tipc_sk_proto_rcv+0x6b9/0xb60 net/tipc/socket.c:2156
 tipc_sk_filter_rcv+0x18f9/0x1a10 net/tipc/socket.c:2350
 tipc_sk_enqueue net/tipc/socket.c:2443 [inline]
 tipc_sk_rcv+0x499/0x1800 net/tipc/socket.c:2495
 tipc_node_xmit+0x1dd/0xaf0 net/tipc/node.c:1701
 tipc_node_xmit_skb+0x99/0xd0 net/tipc/node.c:1766
 tipc_sk_send_ack+0x25c/0x270 net/tipc/socket.c:1824
 tipc_recvstream+0x5a9/0x780 net/tipc/socket.c:2093
 sock_recvmsg_nosec net/socket.c:1078 [inline]
 sock_recvmsg+0x139/0x160 net/socket.c:1100
 ____sys_recvmsg+0xf5/0x280 net/socket.c:2812
 ___sys_recvmsg+0x11f/0x3b0 net/socket.c:2854
 __sys_recvmsg net/socket.c:2887 [inline]
 __do_sys_recvmsg net/socket.c:2893 [inline]
 __se_sys_recvmsg net/socket.c:2890 [inline]
 __x64_sys_recvmsg+0xd1/0x160 net/socket.c:2890
 x64_sys_call+0x2cbf/0x3000 arch/x86/include/generated/asm/syscalls_64.h:48
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888103b958e6 of 2 bytes by task 9059 on cpu 0:
 tsk_conn_cong net/tipc/socket.c:222 [inline]
 tipc_poll+0x1f9/0x340 net/tipc/socket.c:806
 sock_poll+0x21c/0x240 net/socket.c:1443
 vfs_poll include/linux/poll.h:82 [inline]
 __io_arm_poll_handler+0x1ee/0xb80 io_uring/poll.c:581
 io_arm_apoll+0x2eb/0x410 io_uring/poll.c:689
 io_arm_poll_handler+0x131/0x160 io_uring/poll.c:718
 io_queue_async+0x25d/0x2d0 io_uring/io_uring.c:2024
 io_queue_sqe io_uring/io_uring.c:2050 [inline]
 io_submit_sqe io_uring/io_uring.c:2321 [inline]
 io_submit_sqes+0xb8f/0x11b0 io_uring/io_uring.c:2435
 __do_sys_io_uring_enter io_uring/io_uring.c:3285 [inline]
 __se_sys_io_uring_enter+0x1bf/0x1c70 io_uring/io_uring.c:3224
 __x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3224
 x64_sys_call+0x27e4/0x3000 arch/x86/include/generated/asm/syscalls_64.h:427
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x022a -> 0x01a8

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 9059 Comm: syz.8.1935 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/03 10:41 upstream 6bd9ed02871f 6df4c87a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv
2026/01/24 01:35 upstream 5bde837031a3 4f25b9b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv
2026/01/06 19:10 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv
2025/12/31 11:12 upstream c8ebd433459b d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv
2025/12/31 11:09 upstream c8ebd433459b d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv
* Struck through repros no longer work on HEAD.