syzbot


WARNING in sock_map_destroy (3)

Status: upstream: reported C repro on 2026/04/02 19:39
Subsystems: net bpf
[Documentation on labels]
Reported-by: syzbot+b0842d38af58376d1fdc@syzkaller.appspotmail.com
First crash: 220d, last: 2d08h
Cause bisection: introduced by (bisect log) :
commit 8259eb0e06d8f64c700f5fbdb28a5c18e10de291
Author: Jiayuan Chen <jiayuan.chen@linux.dev>
Date: Fri May 16 14:17:12 2025 +0000

  bpf, sockmap: Avoid using sk_socket after free when sending

Crash: WARNING in sock_map_destroy (log)
Repro: C syz .config
  
Fix bisection: failed (error log, bisect log)
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH v1 bpf] sockmap: Fix sk_psock_drop() race vs sock_map_{unhash,close,destroy}(). 2 (2) 2026/04/03 00:39
[syzbot] [net?] [bpf?] WARNING in sock_map_destroy (3) 0 (1) 2026/04/02 19:39
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in sock_map_destroy -1 1 259d 259d 0/3 auto-obsoleted due to no activity on 2025/10/25 15:33
upstream WARNING in sock_map_destroy bpf net -1 C error inconclusive 6 516d 584d 0/29 auto-obsoleted due to no activity on 2025/06/10 15:30
upstream WARNING in sock_map_destroy (2) net bpf -1 1 261d 261d 0/29 closed as invalid on 2025/08/19 19:15
Last patch testing requests (8)
Created Duration User Patch Repo Result
2026/04/02 16:53 51m kuniyu@google.com patch upstream OK log
2026/04/02 02:26 1h30m kuniyu@google.com patch upstream OK log
2026/04/02 00:15 1h35m kuniyu@google.com patch upstream report log
2026/04/01 05:34 23m kuniyu@google.com patch upstream OK log
2026/04/01 02:27 19m kuniyu@google.com upstream report log
2026/01/15 20:47 43m edumazet@google.com upstream report log
2025/09/08 22:50 30m retest repro upstream report log
2025/08/26 04:50 1h22m kuniyu@google.com patch upstream report log
Fix bisection attempts (4)
Created Duration User Patch Repo Result
2026/02/15 02:03 1m bisect fix upstream error job log
2026/01/14 06:44 5h39m bisect fix upstream OK (0) job log log
2025/12/15 00:55 3h24m bisect fix upstream OK (0) job log log
2025/11/14 20:59 3h13m bisect fix upstream OK (0) job log log
Cause bisection attempts (2)
Created Duration User Patch Repo Result
2025/09/03 08:44 10h16m bisect upstream OK (1) job log log
2025/08/26 20:13 35m bisect upstream error job log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 8459 at net/core/sock_map.c:1667 sock_map_destroy+0x28b/0x2b0 net/core/sock_map.c:1667
Modules linked in:
CPU: 1 UID: 0 PID: 8459 Comm: syz.0.1109 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:sock_map_destroy+0x28b/0x2b0 net/core/sock_map.c:1667
Code: 8b 36 49 83 c6 38 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 93 62 22 f9 4d 8b 3e e9 79 ff ff ff e8 a6 2b c3 f8 90 <0f> 0b 90 eb 9c e8 9b 2b c3 f8 4c 89 e7 be 03 00 00 00 e8 0e 4e bc
RSP: 0018:ffffc9000d067be8 EFLAGS: 00010293
RAX: ffffffff88fb30aa RBX: ffff888024832000 RCX: ffff888024283b80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100862e946 R12: dffffc0000000000
R13: ffff888024832000 R14: ffffffff995b2208 R15: ffffffff88fb2e20
FS:  0000555579a7d500(0000) GS:ffff8881269c2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000048c0 CR3: 000000003713a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 inet_csk_destroy_sock+0x166/0x3a0 net/ipv4/inet_connection_sock.c:1294
 __tcp_close+0xcc1/0xfd0 net/ipv4/tcp.c:3262
 tcp_close+0x28/0x110 net/ipv4/tcp.c:3274
 inet_release+0x144/0x190 net/ipv4/af_inet.c:435
 __sock_release net/socket.c:649 [inline]
 sock_close+0xc0/0x240 net/socket.c:1439
 __fput+0x45b/0xa80 fs/file_table.c:468
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f265847ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd158dfbd8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000002ddb0 RCX: 00007f265847ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f26586a7da0 R08: 0000000000000001 R09: 0000000e158dfecf
R10: 0000001b30a20000 R11: 0000000000000246 R12: 00007f26586a5fac
R13: 00007f26586a5fa0 R14: ffffffffffffffff R15: 00007ffd158dfcf0
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/25 22:41 upstream 1b237f190eb3 bf27483f .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in sock_map_destroy
2025/10/11 09:21 upstream 0739473694c4 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in sock_map_destroy
2025/08/25 14:58 upstream 1b237f190eb3 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in sock_map_destroy
2026/01/14 11:27 upstream c537e12daeec d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in sock_map_destroy
* Struck through repros no longer work on HEAD.