syzbot


WARNING in kcm_write_msgs

Status: upstream: reported C repro on 2023/11/28 05:07
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+102e0a04d98b7d969ceb@syzkaller.appspotmail.com
First crash: 182d, last: 18d
Bug presence (1)
Date Name Commit Repro Result
2024/03/05 upstream (ToT) 90d35da658da C [report] WARNING in kcm_write_msgs
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in kcm_write_msgs net C done 503 5d23h 1531d 0/26 upstream: reported C repro on 2020/03/19 07:10
linux-4.14 WARNING in kcm_write_msgs C inconclusive 2 501d 1507d 0/1 upstream: reported C repro on 2020/04/12 04:13
linux-5.15 WARNING in kcm_write_msgs origin:lts-only C error 1 34d 35d 0/3 upstream: reported C repro on 2024/04/23 04:47
linux-4.19 WARNING in kcm_write_msgs C error 8 496d 1520d 0/1 upstream: reported C repro on 2020/03/30 19:34
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2024/05/10 09:12 2h19m bisect fix linux-6.1.y job log (0) log
2024/04/05 01:09 4h24m bisect fix linux-6.1.y job log (0) log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4374 at net/kcm/kcmsock.c:634 kcm_write_msgs+0x800/0xfc0
Modules linked in:
CPU: 0 PID: 4374 Comm: syz-executor374 Not tainted 6.1.80-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kcm_write_msgs+0x800/0xfc0
lr : kcm_write_msgs+0x7fc/0xfc0 net/kcm/kcmsock.c:634
sp : ffff80001e297640
x29: ffff80001e2976c0 x28: 00000000ffffffea x27: dfff800000000000
x26: 0000000000088000 x25: ffff0000e5903c00 x24: ffff0000e5c4de40
x23: ffff0000e44d4b40 x22: ffff0000e44d4c80 x21: 0000000000000011
x20: ffff0000d9274800 x19: 0000000000000000 x18: 00000000000001a8
x17: ffff80019ebee000 x16: ffff8000084f8d9c x15: 0000000000000000
x14: 1ffff00002b040b0 x13: dfff800000000000 x12: 0000000000000003
x11: 0000000000ff0100 x10: 0000000000000000 x9 : ffff8000115fcdbc
x8 : ffff0000d811b780 x7 : ffff8000103b6e90 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000006 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 kcm_write_msgs+0x800/0xfc0
 kcm_sendmsg+0x1964/0x1e8c net/kcm/kcmsock.c:1040
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 sock_write_iter+0x2d8/0x414 net/socket.c:1143
 call_write_iter include/linux/fs.h:2251 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x610/0x914 fs/read_write.c:584
 ksys_write+0x15c/0x26c fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 4962
hardirqs last  enabled at (4961): [<ffff8000081c7770>] __local_bh_enable_ip+0x230/0x470 kernel/softirq.c:401
hardirqs last disabled at (4962): [<ffff800012141c04>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (4960): [<ffff8000103b6fcc>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (4960): [<ffff8000103b6fcc>] release_sock+0x178/0x1cc net/core/sock.c:3510
softirqs last disabled at (4958): [<ffff8000103b6e90>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (4958): [<ffff8000103b6e90>] release_sock+0x3c/0x1cc net/core/sock.c:3497
---[ end trace 0000000000000000 ]---
KCM: Hard failure on kcm_write_msgs

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/05 08:57 linux-6.1.y a3eb3a74aa8c 5fc53669 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in kcm_write_msgs
2023/11/28 05:06 linux-6.1.y 69e434a1cb21 7ec6c044 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in kcm_write_msgs
* Struck through repros no longer work on HEAD.