syzbot


general protection fault in page_vma_mapped_walk

Status: auto-closed as invalid on 2022/01/17 20:48
Reported-by: syzbot+9e8fc6d95f32c64ce562@syzkaller.appspotmail.com
First crash: 382d, last: 382d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 general protection fault in page_vma_mapped_walk 1 1077d 1077d 0/1 auto-closed as invalid on 2020/04/22 07:29
linux-4.14 general protection fault in page_vma_mapped_walk (2) 1 928d 928d 0/1 auto-closed as invalid on 2020/09/19 03:21
linux-4.19 general protection fault in page_vma_mapped_walk 2 382d 501d 0/1 auto-closed as invalid on 2022/03/18 08:11

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 8 Comm: kworker/u4:0 Not tainted 5.16.0-rc1-next-20211118-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:page_vma_mapped_walk+0x7ff/0x24d0 mm/page_vma_mapped.c:203
Code: 8b 44 24 10 80 38 00 0f 85 f8 15 00 00 48 8b 44 24 20 4c 89 f5 48 c1 ed 24 81 e5 f8 0f 00 00 48 03 68 50 48 89 e8 48 c1 e8 03 <42> 80 3c 38 00 0f 85 df 15 00 00 48 8b 6d 00 31 ff 41 89 ec 41 83
RSP: 0018:ffffc90000cd6d70 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffc90000cd6eb0 RCX: 0000000000000000
RDX: ffff888010e7d7c0 RSI: ffffffff81b0ec14 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81b0e5d8 R11: 0000000000000000 R12: 0000000000000000
R13: 0000001b31d23000 R14: 0000001b31d23000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f651b7bb718 CR3: 0000000018ad7000 CR4: 00000000003526e0
Call Trace:
 <TASK>
 page_mkclean_one+0x44c/0x8c0 mm/rmap.c:923
 rmap_walk_file+0x3a5/0x6e0 mm/rmap.c:2356
 rmap_walk+0x10d/0x190 mm/rmap.c:2374
 folio_mkclean+0x174/0x1a0 mm/rmap.c:1003
 folio_clear_dirty_for_io+0x149/0x790 mm/page-writeback.c:2757
 mpage_submit_page+0x80/0x2a0 fs/ext4/inode.c:2075
 mpage_process_page_bufs+0x681/0x7a0 fs/ext4/inode.c:2209
 mpage_prepare_extent_to_map+0x94f/0xe60 fs/ext4/inode.c:2621
 ext4_writepages+0x926/0x3b90 fs/ext4/inode.c:2749
 do_writepages+0x1ab/0x690 mm/page-writeback.c:2364
 __writeback_single_inode+0x126/0xff0 fs/fs-writeback.c:1616
 writeback_sb_inodes+0x53d/0xf30 fs/fs-writeback.c:1881
 __writeback_inodes_wb+0xc6/0x280 fs/fs-writeback.c:1951
 wb_writeback+0x7f8/0xc30 fs/fs-writeback.c:2056
 wb_check_old_data_flush fs/fs-writeback.c:2156 [inline]
 wb_do_writeback fs/fs-writeback.c:2209 [inline]
 wb_workfn+0x8cf/0x12d0 fs/fs-writeback.c:2238
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
---[ end trace 1ebc282721e655c5 ]---
RIP: 0010:page_vma_mapped_walk+0x7ff/0x24d0 mm/page_vma_mapped.c:203
Code: 8b 44 24 10 80 38 00 0f 85 f8 15 00 00 48 8b 44 24 20 4c 89 f5 48 c1 ed 24 81 e5 f8 0f 00 00 48 03 68 50 48 89 e8 48 c1 e8 03 <42> 80 3c 38 00 0f 85 df 15 00 00 48 8b 6d 00 31 ff 41 89 ec 41 83
RSP: 0018:ffffc90000cd6d70 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffc90000cd6eb0 RCX: 0000000000000000
RDX: ffff888010e7d7c0 RSI: ffffffff81b0ec14 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81b0e5d8 R11: 0000000000000000 R12: 0000000000000000
R13: 0000001b31d23000 R14: 0000001b31d23000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6269627718 CR3: 000000006d963000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	8b 44 24 10          	mov    0x10(%rsp),%eax
   4:	80 38 00             	cmpb   $0x0,(%rax)
   7:	0f 85 f8 15 00 00    	jne    0x1605
   d:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
  12:	4c 89 f5             	mov    %r14,%rbp
  15:	48 c1 ed 24          	shr    $0x24,%rbp
  19:	81 e5 f8 0f 00 00    	and    $0xff8,%ebp
  1f:	48 03 68 50          	add    0x50(%rax),%rbp
  23:	48 89 e8             	mov    %rbp,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	0f 85 df 15 00 00    	jne    0x1614
  35:	48 8b 6d 00          	mov    0x0(%rbp),%rbp
  39:	31 ff                	xor    %edi,%edi
  3b:	41 89 ec             	mov    %ebp,%r12d
  3e:	41                   	rex.B
  3f:	83                   	.byte 0x83

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-linux-next-kasan-gce-root 2021/11/18 20:47 linux-next 5191249f8803 31a30fc0 .config log report info general protection fault in page_vma_mapped_walk
* Struck through repros no longer work on HEAD.