syzbot


WARNING in do_new_mount (6)

Status: moderation: reported on 2026/02/18 14:16
Subsystems: fs
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+aa9301d3b66961eb2421@syzkaller.appspotmail.com
First crash: 153d, last: 13h55m
✨ AI Jobs (3)
ID Workflow Result Correct Bug Created Started Finished Revision Error
faead6e8-02da-431d-a649-5ea8a590208e assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in do_new_mount (6) 2026/05/31 16:09 2026/05/31 16:09 2026/05/31 17:18 6b4a844333e83556da95d61d7f207e7ef5cd4bc6

			
		
0dd1d590-dccc-4a13-87e6-f54787afc514 assessment-security 💥 WARNING in do_new_mount (6) 2026/05/15 05:28 2026/05/15 05:28 2026/05/15 05:30 6ccb967e465e832a7bfd7a116ad00d52a0923a5d
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/ea6319647410b1260e...
truncated to first 200 bytes; open job for full error
58385d5e-6dc3-4633-9afa-009a6e06e4da repro WARNING in do_new_mount (6) 2026/03/07 03:20 2026/03/07 03:20 2026/03/07 03:29 31e9c887f7dc24e04b3ca70d0d54fc34141844b0

			
		
Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in do_new_mount -1 2 1061d 1078d 0/3 auto-obsoleted due to no activity on 2023/11/29 20:19
linux-6.1 WARNING in do_new_mount (2) -1 1 224d 224d 0/3 auto-obsoleted due to no activity on 2026/03/15 04:54
upstream WARNING in do_new_mount fs -1 4 1073d 1092d 0/29 auto-obsoleted due to no activity on 2023/11/07 02:18
upstream WARNING in do_new_mount (5) fs -1 1 396d 392d 0/29 auto-obsoleted due to no activity on 2025/09/14 00:27
upstream WARNING in do_new_mount (3) fs -1 1 561d 557d 0/29 auto-obsoleted due to no activity on 2025/03/03 15:54
linux-6.1 WARNING in do_new_mount -1 4 731d 834d 0/3 auto-obsoleted due to no activity on 2024/10/24 11:22
upstream WARNING in do_new_mount (2) fs -1 22 677d 831d 0/29 auto-obsoleted due to no activity on 2024/12/07 21:46
upstream WARNING in do_new_mount (4) fs -1 2 489d 490d 0/29 auto-obsoleted due to no activity on 2025/06/13 20:52

Sample crash report:
ntfs3(loop7): Failed to initialize $Extend/$ObjId.
ntfs3(loop7): failed to convert "c46c" to macturkish
ntfs3(loop7): ino=20, mi_enum_attr
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current)
WARNING: kernel/locking/rtmutex_common.h:193 at debug_rt_mutex_unlock kernel/locking/rtmutex_common.h:193 [inline], CPU#1: syz.7.832/10750
WARNING: kernel/locking/rtmutex_common.h:193 at rt_mutex_slowunlock+0x732/0xa20 kernel/locking/rtmutex.c:1432, CPU#1: syz.7.832/10750
Modules linked in:
CPU: 1 UID: 0 PID: 10750 Comm: syz.7.832 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:debug_rt_mutex_unlock kernel/locking/rtmutex_common.h:193 [inline]
RIP: 0010:rt_mutex_slowunlock+0x739/0xa20 kernel/locking/rtmutex.c:1432
Code: af 8f 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 cf 02 00 00 83 3d db c0 6b 04 00 75 13 48 8d 3d 3e 05 6f 04 48 c7 c6 a0 ff 6c 8b <67> 48 0f b9 3a 90 e9 d1 f9 ff ff 48 8d 3d 35 05 6f 04 67 48 0f b9
RSP: 0000:ffffc900048afbc0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff888067dcd728 RCX: 0000000000080000
RDX: ffffc9000ed43000 RSI: ffffffff8b6cffa0 RDI: ffffffff8fb2e0b0
RBP: ffffc900048afcb0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f5f389 R12: dffffc0000000000
R13: 1ffff92000915f80 R14: ffff888067dcd6d8 R15: 0000000000000246
FS:  00007f26cf5966c0(0000) GS:ffff888125d49000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f26c7e1b000 CR3: 0000000030e76000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:1034 [inline]
 __unlock_mount fs/namespace.c:2808 [inline]
 unlock_mount fs/namespace.c:2818 [inline]
 do_new_mount_fc fs/namespace.c:3788 [inline]
 do_new_mount+0x82d/0xdc0 fs/namespace.c:3841
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f26d133de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f26cf596028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f26d15c5fa0 RCX: 00007f26d133de99
RDX: 0000200000000200 RSI: 00002000000001c0 RDI: 0000000000000000
RBP: 00007f26d13d3eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000016 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f26d15c6038 R14: 00007f26d15c5fa0 R15: 00007ffcc6ed4238
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	48 c1 e8 03          	shr    $0x3,%rax
   4:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
   9:	84 c0                	test   %al,%al
   b:	0f 85 cf 02 00 00    	jne    0x2e0
  11:	83 3d db c0 6b 04 00 	cmpl   $0x0,0x46bc0db(%rip)        # 0x46bc0f3
  18:	75 13                	jne    0x2d
  1a:	48 8d 3d 3e 05 6f 04 	lea    0x46f053e(%rip),%rdi        # 0x46f055f
  21:	48 c7 c6 a0 ff 6c 8b 	mov    $0xffffffff8b6cffa0,%rsi
* 28:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2d:	90                   	nop
  2e:	e9 d1 f9 ff ff       	jmp    0xfffffa04
  33:	48 8d 3d 35 05 6f 04 	lea    0x46f0535(%rip),%rdi        # 0x46f056f
  3a:	67                   	addr32
  3b:	48                   	rex.W
  3c:	0f                   	.byte 0xf
  3d:	b9                   	.byte 0xb9

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/17 07:57 upstream fce2dfa773ce 7f27c57a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in do_new_mount
2026/06/02 06:36 upstream 6f3ed7fec72f 1095583b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in do_new_mount
2026/05/14 09:06 upstream e1914add2799 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in do_new_mount
2026/04/29 05:45 upstream dca922e019dd 95008c03 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in do_new_mount
2026/04/22 16:18 upstream 6596a02b2078 4595e353 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in do_new_mount
2026/03/07 13:07 upstream 651690480a96 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in do_new_mount
2026/02/20 08:09 upstream 8bf22c33e7a1 17d780d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in do_new_mount
2026/02/14 14:05 upstream c22e26bd0906 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in do_new_mount
2026/02/25 16:13 upstream 7dff99b35460 c162cde9 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in do_new_mount
* Struck through repros no longer work on HEAD.