syzbot


BUG: unable to handle kernel paging request in fuse_dev_do_write (2)

Status: premoderation: reported on 2025/12/02 15:32
Reported-by: syzbot+ab61c347598ac7703ea8@syzkaller.appspotmail.com
First crash: 8d10h, last: 8d10h
Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 BUG: unable to handle kernel paging request in fuse_dev_do_write 8 18 882d 947d 0/2 auto-obsoleted due to no activity on 2023/09/03 17:45
android-54 BUG: unable to handle kernel paging request in fuse_dev_do_write 8 C 213 225d 1821d 0/2 upstream: reported C repro on 2020/12/15 11:21
android-49 BUG: unable to handle kernel paging request in fuse_dev_do_write 8 C 46 2245d 2434d 0/3 public: reported C repro on 2019/04/13 00:00
android-5-15 BUG: unable to handle kernel paging request in fuse_dev_do_write 8 2 883d 884d 0/2 auto-obsoleted due to no activity on 2023/10/10 01:15
android-5-10 BUG: unable to handle kernel paging request in fuse_dev_do_write (4) 8 syz 18 22h57m 25d 0/2 premoderation: reported syz repro on 2025/11/15 21:25
android-5-10 BUG: unable to handle kernel paging request in fuse_dev_do_write (2) 8 1 746d 746d 0/2 auto-obsoleted due to no activity on 2024/02/23 07:02
android-6-1 BUG: unable to handle kernel paging request in fuse_dev_do_write origin:downstream 8 C done error 35 25d 937d 0/2 upstream: reported C repro on 2023/05/18 20:01
android-5-10 BUG: unable to handle kernel paging request in fuse_dev_do_write (3) 8 1 626d 626d 0/2 auto-obsoleted due to no activity on 2024/06/22 11:39
upstream KASAN: slab-out-of-bounds Write in fuse_dev_do_write fuse 23 C 6 105d 110d 29/29 fixed on 2025/10/29 21:02

Sample crash report:
BUG: unable to handle page fault for address: ffffed10481341ff
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 23fff2067 P4D 23fff2067 PUD 23fff0067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 7168 Comm: syz.3.1705 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:fuse_dev_do_write+0x178a/0x46e0 fs/fuse/dev.c:1953
Code: 63 b2 ff 4d 8b 36 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 66 2d 00 00 45 8b 3f 41 ff cf 4d 01 f7 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 67 2d 00 00 41 c6 07 00 41 bf a0 00 00
RSP: 0018:ffffc90000d078e0 EFLAGS: 00010a07
RAX: 1ffff110481341ff RBX: 1ffff110292454a9 RCX: 0000000000080000
RDX: ffffc9000b55e000 RSI: 0000000000000054 RDI: 0000000000000055
RBP: ffffc90000d07be8 R08: dffffc0000000000 R09: fffff94000f3134f
R10: fffff94000f3134f R11: 1ffffd4000f3134e R12: 1ffff110292454a6
R13: dffffc0000000000 R14: ffff8881409a1000 R15: ffff8882409a0fff
FS:  00007f4c6fa0e6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffed10481341ff CR3: 000000010db42000 CR4: 00000000003506a0
Call Trace:
 <TASK>
 fuse_dev_write+0xf3/0x130 fs/fuse/dev.c:2003
 call_write_iter include/linux/fs.h:2212 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x802/0xf70 fs/read_write.c:594
 ksys_write+0x140/0x240 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:656
 x64_sys_call+0x8ef/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4c70fc7749
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:00007f4c6fa0e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4c7121e090 RCX: 00007f4c70fc7749
RDX: 0000000000000010 RSI: 00002000000004c0 RDI: 0000000000000004
RBP: 00007f4c7104bf91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4c7121e128 R14: 00007f4c7121e090 R15: 00007ffce155c668
 </TASK>
Modules linked in:
CR2: ffffed10481341ff
---[ end trace 0af701b522ca81d2 ]---
RIP: 0010:fuse_dev_do_write+0x178a/0x46e0 fs/fuse/dev.c:1953
Code: 63 b2 ff 4d 8b 36 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 66 2d 00 00 45 8b 3f 41 ff cf 4d 01 f7 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 67 2d 00 00 41 c6 07 00 41 bf a0 00 00
RSP: 0018:ffffc90000d078e0 EFLAGS: 00010a07
RAX: 1ffff110481341ff RBX: 1ffff110292454a9 RCX: 0000000000080000
RDX: ffffc9000b55e000 RSI: 0000000000000054 RDI: 0000000000000055
RBP: ffffc90000d07be8 R08: dffffc0000000000 R09: fffff94000f3134f
R10: fffff94000f3134f R11: 1ffffd4000f3134e R12: 1ffff110292454a6
R13: dffffc0000000000 R14: ffff8881409a1000 R15: ffff8882409a0fff
FS:  00007f4c6fa0e6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffed10481341ff CR3: 000000010db42000 CR4: 00000000003506a0
----------------
Code disassembly (best guess):
   0:	63 b2 ff 4d 8b 36    	movsxd 0x368b4dff(%rdx),%esi
   6:	4c 89 f8             	mov    %r15,%rax
   9:	48 c1 e8 03          	shr    $0x3,%rax
   d:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax
  12:	84 c0                	test   %al,%al
  14:	0f 85 66 2d 00 00    	jne    0x2d80
  1a:	45 8b 3f             	mov    (%r15),%r15d
  1d:	41 ff cf             	dec    %r15d
  20:	4d 01 f7             	add    %r14,%r15
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 67 2d 00 00    	jne    0x2d9e
  37:	41 c6 07 00          	movb   $0x0,(%r15)
  3b:	41                   	rex.B
  3c:	bf                   	.byte 0xbf
  3d:	a0                   	.byte 0xa0

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/02 15:32 android13-5.15-lts 057fdbf6d3c7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 BUG: unable to handle kernel paging request in fuse_dev_do_write
2025/12/02 15:32 android13-5.15-lts 057fdbf6d3c7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 BUG: unable to handle kernel paging request in fuse_dev_do_write
* Struck through repros no longer work on HEAD.