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general protection fault in __umount_mnt

Status: fixed on 2026/05/21 07:49
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+e4470cc28308f2081ec8@syzkaller.appspotmail.com
Fix commit: ad4999496e73 mount: always duplicate mount
First crash: 69d, last: 57d
Cause bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
ac20250f-63cf-4362-8a81-82eb2626df78 assessment-security 💥 general protection fault in __umount_mnt 2026/05/14 09:41 2026/05/14 09:41 2026/05/14 09:42 6ccb967e465e832a7bfd7a116ad00d52a0923a5d failed to run ["git" "pull" "origin" "HEAD" "--depth=1" "--allow-unrelated-histories"]: exit status 128 From /app/workdir/repo/linux * branch HEAD -> FETCH_HEAD Updating files: 27% (25619/93750) Updating files: 28% (26250/93750) Updating files: 29% (27188/93750) Updating files: 30% (28125/93750) Updating files: 31% (29063/93750) Updating files: 32% (30000/93750) Updating files: 33% (30938/93750) Updating files: 34% (31875/93750) Updating files: 35% (32813/93750) Updating files: 36% (33750/93750) Updating files: 36% (34137/93750) Updating files: 37% (34688/93750) Updating files: 38% (35625/93750) Updating files: 39% (36563/93750) Updating files: 39% (37216/93750) Updating files: 39% (37320/93750) error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_11_0_0_offset.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_11_0_0_sh_mask.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_11_0_3_offset.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_11_0_3_sh_mask.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_11_5_0_offset.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_11_5_0_sh_mask.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_12_0_0_offset.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_12_0_0_sh_mask.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_12_1_0_offset.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_12_1_0_sh_mask.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_0_default.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_0_offset.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_0_sh_mask.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_1_offset.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_1_sh_mask.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_2_1_offset.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_2_1_sh_mask.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_4_1_offset.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_4_1_sh_mask.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_4_2_offset.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_4_2_sh_mask.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_4_3_offset.h error: unable to write file drivers/gpu/drm/amd/include/asic_reg/gc/gc_9_4_3_sh_mask.h fatal: cannot create directory at 'drivers/gpu/drm/amd/include/asic_reg/gca': No space left on device
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [fs?] general protection fault in __umount_mnt 3 (9) 2026/03/28 21:41
[PATCH] fs/namespace: fix double hlist_del_init of mnt_mp_list in get_detached_copy() 2 (2) 2026/03/21 08:22
▶ ▼ Last patch testing requests (4)
Created Duration User Patch Repo Result
2026/03/28 21:09 31m hdanton@sina.com https://github.com/brauner/linux.git 14594a141c760dd4c462b38d73406e1b48e44b84 OK log
2026/03/24 08:44 22m brauner@kernel.org https://github.com/brauner/linux.git 14594a141c760dd4c462b38d73406e1b48e44b84 OK log
2026/03/23 15:17 0m brauner@kernel.org patch https://github.com/brauner/linux/tree/vfs-7.1.mount 14594a141c760dd4c462b38d73406e1b48e44b84 error
2026/03/21 05:53 23m kartikey406@gmail.com patch upstream OK log

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xfbd59c0000000024: 0000 [#1] SMP KASAN PTI
KASAN: maybe wild-memory-access in range [0xdead000000000120-0xdead000000000127]
CPU: 1 UID: 0 PID: 6143 Comm: syz.1.48 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__hlist_del include/linux/list.h:992 [inline]
RIP: 0010:hlist_del_init include/linux/list.h:1020 [inline]
RIP: 0010:__umount_mnt+0x24e/0x490 fs/namespace.c:997
Code: 85 e4 74 61 4d 8d be f8 00 00 00 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 ac 3f e3 ff 4d 8b 2f 4c 89 e0 48 c1 e8 03 <80> 3c 28 00 74 08 4c 89 e7 e8 84 40 e3 ff 4d 89 2c 24 4d 85 ed 74
RSP: 0018:ffffc900033f7a20 EFLAGS: 00010a06
RAX: 1bd5a00000000024 RBX: ffff8880721cd348 RCX: ffff888029698000
RDX: 0000000000000000 RSI: ffffffff8ecd83a0 RDI: ffff8880721cd3b8
RBP: dffffc0000000000 R08: ffffffff905495f7 R09: 1ffffffff20a92be
R10: dffffc0000000000 R11: fffffbfff20a92bf R12: dead000000000122
R13: dead000000000100 R14: ffff8880721cd340 R15: ffff8880721cd438
FS:  00005555712af500(0000) GS:ffff8881250e7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffa7bbe92f8 CR3: 0000000056c70000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 umount_mnt fs/namespace.c:1008 [inline]
 umount_tree+0x925/0xd90 fs/namespace.c:1819
 put_mnt_ns+0x1d6/0x2f0 fs/namespace.c:6264
 evict+0x61e/0xb10 fs/inode.c:846
 __dentry_kill+0x1a2/0x5e0 fs/dcache.c:670
 finish_dput+0xc9/0x480 fs/dcache.c:879
 __fput+0x691/0xa70 fs/file_table.c:477
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fad8559c799
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:00007ffc95482d18 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fad85817da0 RCX: 00007fad8559c799
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fad85817da0 R08: 00007fad85816038 R09: 0000000000000000
R10: 000000000003fda8 R11: 0000000000000246 R12: 000000000001b76f
R13: 00007fad8581609c R14: 000000000001b570 R15: 00007fad85816090
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__hlist_del include/linux/list.h:992 [inline]
RIP: 0010:hlist_del_init include/linux/list.h:1020 [inline]
RIP: 0010:__umount_mnt+0x24e/0x490 fs/namespace.c:997
Code: 85 e4 74 61 4d 8d be f8 00 00 00 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 ac 3f e3 ff 4d 8b 2f 4c 89 e0 48 c1 e8 03 <80> 3c 28 00 74 08 4c 89 e7 e8 84 40 e3 ff 4d 89 2c 24 4d 85 ed 74
RSP: 0018:ffffc900033f7a20 EFLAGS: 00010a06
RAX: 1bd5a00000000024 RBX: ffff8880721cd348 RCX: ffff888029698000
RDX: 0000000000000000 RSI: ffffffff8ecd83a0 RDI: ffff8880721cd3b8
RBP: dffffc0000000000 R08: ffffffff905495f7 R09: 1ffffffff20a92be
R10: dffffc0000000000 R11: fffffbfff20a92bf R12: dead000000000122
R13: dead000000000100 R14: ffff8880721cd340 R15: ffff8880721cd438
FS:  00005555712af500(0000) GS:ffff8881250e7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffa7bbe92f8 CR3: 0000000056c70000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	85 e4                	test   %esp,%esp
   2:	74 61                	je     0x65
   4:	4d 8d be f8 00 00 00 	lea    0xf8(%r14),%r15
   b:	4c 89 f8             	mov    %r15,%rax
   e:	48 c1 e8 03          	shr    $0x3,%rax
  12:	80 3c 28 00          	cmpb   $0x0,(%rax,%rbp,1)
  16:	74 08                	je     0x20
  18:	4c 89 ff             	mov    %r15,%rdi
  1b:	e8 ac 3f e3 ff       	call   0xffe33fcc
  20:	4d 8b 2f             	mov    (%r15),%r13
  23:	4c 89 e0             	mov    %r12,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	80 3c 28 00          	cmpb   $0x0,(%rax,%rbp,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 e7             	mov    %r12,%rdi
  33:	e8 84 40 e3 ff       	call   0xffe340bc
  38:	4d 89 2c 24          	mov    %r13,(%r12)
  3c:	4d 85 ed             	test   %r13,%r13
  3f:	74                   	.byte 0x74

Crashes (21):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/28 15:12 linux-next 3b058d1aeeef 356bdfc9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce general protection fault in __umount_mnt
2026/03/28 13:15 linux-next 3b058d1aeeef 356bdfc9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/27 10:07 linux-next 66ba480978ce 50cdcaa1 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce general protection fault in __umount_mnt
2026/03/27 00:04 linux-next e77a5a5cfe43 fca8d360 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/21 11:56 linux-next 785f0eb2f85d 5b92003d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/21 08:50 linux-next 785f0eb2f85d 5b92003d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/21 07:31 linux-next 785f0eb2f85d 5b92003d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/21 06:13 linux-next 785f0eb2f85d 5b92003d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/21 04:51 linux-next 785f0eb2f85d 5b92003d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/19 23:51 linux-next 8e42d2514a7e bd6dcb30 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/19 22:38 linux-next 8e42d2514a7e bd6dcb30 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/19 21:49 linux-next 8e42d2514a7e bd6dcb30 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/19 20:31 linux-next 8e42d2514a7e bd6dcb30 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/19 19:44 linux-next 8e42d2514a7e bd6dcb30 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/31 01:48 linux-next cf7c3c02fdd0 d0af506e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/31 01:48 linux-next cf7c3c02fdd0 d0af506e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/30 03:23 linux-next 3b058d1aeeef 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/30 02:31 linux-next 3b058d1aeeef 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/26 18:09 linux-next e77a5a5cfe43 fca8d360 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/22 10:21 linux-next 785f0eb2f85d 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
2026/03/19 11:29 linux-next 8e42d2514a7e bd6dcb30 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __umount_mnt
* Struck through repros no longer work on HEAD.