syzbot
general protection fault in md_handle_request
Status:
upstream: reported C repro on 2026/10/02 23:25
Subsystems:
raid
Labels:
prio:high
[Documentation on labels]
Reported-by: syzbot+89a9ab2a134d092fffae@syzkaller.appspotmail.com
First crash: 43d, last: 4h45m
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Last patch testing requests (3)
Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 1 UID: 0 PID: 6372 Comm: syz-executor143 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:md_handle_request+0xadd/0xe60 drivers/md/md.c:417
Code: 24 90 00 00 00 48 8b 84 24 a8 00 00 00 42 80 3c 20 00 74 08 48 89 df e8 f1 b2 93 f9 48 8b 1b 48 83 c3 18 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 d4 b2 93 f9 4c 8b 1b 48 8b bc 24
RSP: 0018:ffffc9000415f5c0 EFLAGS: 00010206
RAX: 0000000000000003 RBX: 0000000000000018 RCX: ffff88802b29ddc0
RDX: 0000000000000000 RSI: ffffffff8e9dafe5 RDI: ffff88802b29ddc0
RBP: ffffc9000415f778 R08: ffffffff88a749bc R09: 0000000000000000
R10: 0000000000000009 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff9200082bf70 R14: ffff88807e3680c8 R15: ffff88807e368238
FS: 000055556ca3c400(0000) GS:ffff888124723000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8a7dc59000 CR3: 000000007831e000 CR4: 00000000003526f0
Call Trace:
<TASK>
__submit_bio+0x27f/0x340 block/blk-core.c:681
__submit_bio_noacct block/blk-core.c:724 [inline]
submit_bio_noacct_nocheck+0x4e8/0xa40 block/blk-core.c:792
bio_await block/bio.c:1506 [inline]
submit_bio_wait+0x12a/0x250 block/bio.c:1524
__blkdev_direct_IO_simple block/fops.c:115 [inline]
blkdev_direct_IO+0x1167/0x18e0 block/fops.c:451
blkdev_read_iter+0x223/0x420 block/fops.c:849
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x595/0xa80 fs/read_write.c:574
ksys_pread64 fs/read_write.c:764 [inline]
__do_sys_pread64 fs/read_write.c:772 [inline]
__se_sys_pread64 fs/read_write.c:769 [inline]
__x64_sys_pread64+0x196/0x220 fs/read_write.c:769
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8a7dca9077
Code: 48 89 fa 4c 89 df e8 98 1e 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc5a7b78d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000011
RAX: ffffffffffffffda RBX: 000055556ca3c400 RCX: 00007f8a7dca9077
RDX: 0000000000001000 RSI: 000055556ca3e000 RDI: 0000000000000009
RBP: 0000000000000096 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc5a7b79e0
R13: 00007ffc5a7b79d4 R14: 00007ffc5a7b7954 R15: 00007f8a7dc59000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:md_handle_request+0xadd/0xe60 drivers/md/md.c:417
Code: 24 90 00 00 00 48 8b 84 24 a8 00 00 00 42 80 3c 20 00 74 08 48 89 df e8 f1 b2 93 f9 48 8b 1b 48 83 c3 18 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 d4 b2 93 f9 4c 8b 1b 48 8b bc 24
RSP: 0018:ffffc9000415f5c0 EFLAGS: 00010206
RAX: 0000000000000003 RBX: 0000000000000018 RCX: ffff88802b29ddc0
RDX: 0000000000000000 RSI: ffffffff8e9dafe5 RDI: ffff88802b29ddc0
RBP: ffffc9000415f778 R08: ffffffff88a749bc R09: 0000000000000000
R10: 0000000000000009 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff9200082bf70 R14: ffff88807e3680c8 R15: ffff88807e368238
FS: 000055556ca3c400(0000) GS:ffff888124623000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8a7dd14100 CR3: 000000007831e000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 24 90 and $0x90,%al
2: 00 00 add %al,(%rax)
4: 00 48 8b add %cl,-0x75(%rax)
7: 84 24 a8 test %ah,(%rax,%rbp,4)
a: 00 00 add %al,(%rax)
c: 00 42 80 add %al,-0x80(%rdx)
f: 3c 20 cmp $0x20,%al
11: 00 74 08 48 add %dh,0x48(%rax,%rcx,1)
15: 89 df mov %ebx,%edi
17: e8 f1 b2 93 f9 call 0xf993b30d
1c: 48 8b 1b mov (%rbx),%rbx
1f: 48 83 c3 18 add $0x18,%rbx
23: 48 89 d8 mov %rbx,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 48 89 df mov %rbx,%rdi
34: e8 d4 b2 93 f9 call 0xf993b30d
39: 4c 8b 1b mov (%rbx),%r11
3c: 48 rex.W
3d: 8b .byte 0x8b
3e: bc .byte 0xbc
3f: 24 .byte 0x24
* Struck through repros no longer work on HEAD.