[moderation] [block?] general protection fault in deadline_write1_next_rq_show

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 33d8d8ec31b5 Merge tag 'input-for-v7.1-rc6' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10fa5e7a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=4e4d2284f2ffa41
dashboard link: https://syzkaller.appspot.com/bug?extid=5d2df22762d003bd81cd
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
CC: [ax...@kernel.dk linux...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/dc7cc9bfa7a9/disk-33d8d8ec.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fb8c637b173a/vmlinux-33d8d8ec.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2ef9e0a423af/bzImage-33d8d8ec.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5d2df2...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 UID: 0 PID: 7102 Comm: syz.3.245 Tainted: G U syzkaller #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:deadline_write1_next_rq_show+0x57/0x1e0 block/mq-deadline.c:855
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 8f 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5b 08 48 8d 7b 10 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 62 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b
RSP: 0018:ffffc9000438fa18 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc900055c9000
RDX: 0000000000000002 RSI: ffffffff84e1e25f RDI: 0000000000000010
RBP: 0000000000000001 R08: 0000000000000007 R09: fffffffffffff000
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880269cd800 R15: ffff888021f70498
FS: 00007f93e1b196c0(0000) GS:ffff88812438e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d21eff8 CR3: 0000000078f0a000 CR4: 00000000003526f0
Call Trace:
<TASK>
traverse.part.0.constprop.0+0x107/0x650 fs/seq_file.c:112
traverse fs/seq_file.c:99 [inline]
seq_read_iter+0x93f/0x1270 fs/seq_file.c:196
seq_read+0x33b/0x4c0 fs/seq_file.c:163
full_proxy_read+0x135/0x1a0 fs/debugfs/file.c:378
vfs_read+0x1e4/0xb30 fs/read_write.c:572
ksys_pread64 fs/read_write.c:765 [inline]
__do_sys_pread64 fs/read_write.c:773 [inline]
__se_sys_pread64 fs/read_write.c:770 [inline]
__x64_sys_pread64+0x1eb/0x250 fs/read_write.c:770
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f93e0b9ce59
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:00007f93e1b19028 EFLAGS: 00000246 ORIG_RAX: 0000000000000011
RAX: ffffffffffffffda RBX: 00007f93e0e15fa0 RCX: 00007f93e0b9ce59
RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f93e0c32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f93e0e16038 R14: 00007f93e0e15fa0 R15: 00007fffa2b1bed8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:deadline_write1_next_rq_show+0x57/0x1e0 block/mq-deadline.c:855
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 8f 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5b 08 48 8d 7b 10 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 62 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b
RSP: 0018:ffffc9000438fa18 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc900055c9000
RDX: 0000000000000002 RSI: ffffffff84e1e25f RDI: 0000000000000010
RBP: 0000000000000001 R08: 0000000000000007 R09: fffffffffffff000
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880269cd800 R15: ffff888021f70498
FS: 00007f93e1b196c0(0000) GS:ffff88812448e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f93e0bea540 CR3: 0000000078f0a000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 48 89 fa mov %rdi,%rdx
3: 48 c1 ea 03 shr $0x3,%rdx
7: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
b: 0f 85 8f 01 00 00 jne 0x1a0
11: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
18: fc ff df
1b: 48 8b 5b 08 mov 0x8(%rbx),%rbx
1f: 48 8d 7b 10 lea 0x10(%rbx),%rdi
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 0f 85 62 01 00 00 jne 0x196
34: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
3b: fc ff df
3e: 48 rex.W
3f: 8b .byte 0x8b


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