Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 1116 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:bio_init block/bio.c:214 [inline]
RIP: 0010:bio_init_inline include/linux/bio.h:435 [inline]
RIP: 0010:bio_alloc_bioset+0x664/0xc10 block/bio.c:593
Code: 04 24 00 00 00 00 41 8d 46 ff 0f b7 d8 bf 04 00 00 00 89 de e8 6d b0 3a fd 66 83 fb 04 0f 83 db 00 00 00 4c 89 f8 48 c1 e8 03 <80> 3c 28 00 74 08 4c 89 ff e8 3e 27 a4 fd 49 c7 07 00 00 00 00 49
RSP: 0000:ffffc9000576efe8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88802998bd00 RSI: 0000000000000000 RDI: 0000000000000004
RBP: dffffc0000000000 R08: ffffffff905435f7 R09: 1ffffffff20a86be
R10: dffffc0000000000 R11: fffffbfff20a86bf R12: 0000000000092800
R13: ffffffff9a8dc840 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124de1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f51b88511d0 CR3: 0000000072570000 CR4: 00000000003526f0
Call Trace:
<TASK>
bio_alloc include/linux/bio.h:373 [inline]
submit_bh_wbc+0x22d/0x650 fs/buffer.c:2816
__block_write_full_folio+0x810/0xe10 fs/buffer.c:1930
blkdev_writepages+0xef/0x1b0 block/fops.c:486
do_writepages+0x32e/0x550 mm/page-writeback.c:2554
__writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1750
writeback_sb_inodes+0x992/0x1a20 fs/fs-writeback.c:2042
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2118
wb_writeback+0x46a/0xb70 fs/fs-writeback.c:2229
wb_check_start_all fs/fs-writeback.c:2355 [inline]
wb_do_writeback fs/fs-writeback.c:2381 [inline]
wb_workfn+0x95b/0xf50 fs/fs-writeback.c:2414
process_one_work+0x9ab/0x1780 kernel/workqueue.c:3288
process_scheduled_works kernel/workqueue.c:3379 [inline]
worker_thread+0xba8/0x11e0 kernel/workqueue.c:3465
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:bio_init block/bio.c:214 [inline]
RIP: 0010:bio_init_inline include/linux/bio.h:435 [inline]
RIP: 0010:bio_alloc_bioset+0x664/0xc10 block/bio.c:593
Code: 04 24 00 00 00 00 41 8d 46 ff 0f b7 d8 bf 04 00 00 00 89 de e8 6d b0 3a fd 66 83 fb 04 0f 83 db 00 00 00 4c 89 f8 48 c1 e8 03 <80> 3c 28 00 74 08 4c 89 ff e8 3e 27 a4 fd 49 c7 07 00 00 00 00 49
RSP: 0000:ffffc9000576efe8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88802998bd00 RSI: 0000000000000000 RDI: 0000000000000004
RBP: dffffc0000000000 R08: ffffffff905435f7 R09: 1ffffffff20a86be
R10: dffffc0000000000 R11: fffffbfff20a86bf R12: 0000000000092800
R13: ffffffff9a8dc840 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124de1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564154e50330 CR3: 000000005d868000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 04 24 add $0x24,%al
2: 00 00 add %al,(%rax)
4: 00 00 add %al,(%rax)
6: 41 8d 46 ff lea -0x1(%r14),%eax
a: 0f b7 d8 movzwl %ax,%ebx
d: bf 04 00 00 00 mov $0x4,%edi
12: 89 de mov %ebx,%esi
14: e8 6d b0 3a fd call 0xfd3ab086
19: 66 83 fb 04 cmp $0x4,%bx
1d: 0f 83 db 00 00 00 jae 0xfe
23: 4c 89 f8 mov %r15,%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 ff mov %r15,%rdi
33: e8 3e 27 a4 fd call 0xfda42776
38: 49 c7 07 00 00 00 00 movq $0x0,(%r15)
3f: 49 rex.WB