Re: [syzbot] WARNING in __set_page_dirty

From: syzbot
Date: Thu Aug 12 2021 - 23:30:30 EST


syzbot has found a reproducer for the following issue on:

HEAD commit: f8fbb47c6e86 Merge branch 'for-v5.14' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=125aadf6300000
kernel config: https://syzkaller.appspot.com/x/.config?x=e3a20bae04b96ccd
dashboard link: https://syzkaller.appspot.com/bug?extid=0d5b462a6f07447991b3
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=122742ee300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17925381300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0d5b462a6f07447991b3@xxxxxxxxxxxxxxxxxxxxxxxxx

NILFS (loop0): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8496 at include/linux/backing-dev.h:283 inode_to_wb include/linux/backing-dev.h:283 [inline]
WARNING: CPU: 0 PID: 8496 at include/linux/backing-dev.h:283 account_page_dirtied mm/page-writeback.c:2435 [inline]
WARNING: CPU: 0 PID: 8496 at include/linux/backing-dev.h:283 __set_page_dirty+0xace/0x1070 mm/page-writeback.c:2483
Modules linked in:
CPU: 0 PID: 8496 Comm: segctord Not tainted 5.14.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:inode_to_wb include/linux/backing-dev.h:283 [inline]
RIP: 0010:account_page_dirtied mm/page-writeback.c:2435 [inline]
RIP: 0010:__set_page_dirty+0xace/0x1070 mm/page-writeback.c:2483
Code: a8 01 00 00 be ff ff ff ff 48 8d 78 70 e8 ea 60 8d 07 31 ff 89 c3 89 c6 e8 cf a6 d8 ff 85 db 0f 85 ac f7 ff ff e8 82 9f d8 ff <0f> 0b e9 a0 f7 ff ff e8 76 9f d8 ff 4c 8d 75 08 48 b8 00 00 00 00
RSP: 0018:ffffc9000175f8c8 EFLAGS: 00010093
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8880263b9c40 RSI: ffffffff819d083e RDI: 0000000000000003
RBP: ffffea000082dac0 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff819d0831 R11: 0000000000000000 R12: 0000000000000293
R13: ffff888037e60138 R14: ffff888037e60488 R15: ffff888037e602e0
FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005593610abbe0 CR3: 0000000016882000 CR4: 0000000000350ef0
Call Trace:
mark_buffer_dirty+0x49a/0x5e0 fs/buffer.c:1108
nilfs_btree_propagate_p fs/nilfs2/btree.c:1889 [inline]
nilfs_btree_propagate+0x4ae/0xea0 fs/nilfs2/btree.c:2085
nilfs_bmap_propagate+0x73/0x170 fs/nilfs2/bmap.c:337
nilfs_collect_dat_data+0x45/0xd0 fs/nilfs2/segment.c:625
nilfs_segctor_apply_buffers+0x14a/0x470 fs/nilfs2/segment.c:1009
nilfs_segctor_scan_file+0x3e4/0x700 fs/nilfs2/segment.c:1058
nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1224 [inline]
nilfs_segctor_collect fs/nilfs2/segment.c:1494 [inline]
nilfs_segctor_do_construct+0x16ee/0x6b20 fs/nilfs2/segment.c:2036
nilfs_segctor_construct+0x7a7/0xb30 fs/nilfs2/segment.c:2372
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2480 [inline]
nilfs_segctor_thread+0x3c3/0xf90 fs/nilfs2/segment.c:2563
kthread+0x3e5/0x4d0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
----------------
Code disassembly (best guess):
0: a8 01 test $0x1,%al
2: 00 00 add %al,(%rax)
4: be ff ff ff ff mov $0xffffffff,%esi
9: 48 8d 78 70 lea 0x70(%rax),%rdi
d: e8 ea 60 8d 07 callq 0x78d60fc
12: 31 ff xor %edi,%edi
14: 89 c3 mov %eax,%ebx
16: 89 c6 mov %eax,%esi
18: e8 cf a6 d8 ff callq 0xffd8a6ec
1d: 85 db test %ebx,%ebx
1f: 0f 85 ac f7 ff ff jne 0xfffff7d1
25: e8 82 9f d8 ff callq 0xffd89fac
2a: 0f 0b ud2 <-- trapping instruction
2c: e9 a0 f7 ff ff jmpq 0xfffff7d1
31: e8 76 9f d8 ff callq 0xffd89fac
36: 4c 8d 75 08 lea 0x8(%rbp),%r14
3a: 48 rex.W
3b: b8 00 00 00 00 mov $0x0,%eax