Re: [syzbot] [bfs?] general protection fault in bfs_get_block (3)

[syzbot <syzbot+f51a2a34984e4d8888fd@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in mark_buffer_dirty

------------[ cut here ]------------
WARNING: CPU: 0 PID: 5982 at fs/buffer.c:1177 mark_buffer_dirty+0x2e5/0x520 fs/buffer.c:1177
Modules linked in:
CPU: 0 UID: 0 PID: 5982 Comm: syz.0.15 Not tainted 6.12.0-rc5-syzkaller-00308-g3e5e6c9900c3-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:mark_buffer_dirty+0x2e5/0x520 fs/buffer.c:1177
Code: 89 df e8 fe 82 db ff 48 8b 3b be 20 00 00 00 5b 41 5e 41 5f 5d e9 fb e8 fb ff e8 26 c4 71 ff e9 73 ff ff ff e8 1c c4 71 ff 90 <0f> 0b 90 e9 61 fd ff ff e8 0e c4 71 ff 90 0f 0b 90 e9 88 fd ff ff
RSP: 0018:ffffc9000cecf848 EFLAGS: 00010293
RAX: ffffffff82231604 RBX: ffff8880474fa301 RCX: ffff8880363cc880
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff82231361 R09: 1ffff11008e9f474
R10: dffffc0000000000 R11: ffffed1008e9f475 R12: ffff88804243f658
R13: dffffc0000000000 R14: ffff8880474fa3a0 R15: ffff8880516f1c00
FS:  00007fd80c3ae6c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f88016aa0a0 CR3: 0000000040b52000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bfs_move_block fs/bfs/file.c:49 [inline]
 bfs_move_blocks fs/bfs/file.c:62 [inline]
 bfs_get_block+0x64e/0xb70 fs/bfs/file.c:131
 __block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2121
 block_write_begin+0x8f/0x120 fs/buffer.c:2231
 bfs_write_begin+0x35/0xd0 fs/bfs/file.c:184
 generic_perform_write+0x344/0x6d0 mm/filemap.c:4054
 generic_file_write_iter+0xae/0x310 mm/filemap.c:4181
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0xaeb/0xd30 fs/read_write.c:683
 ksys_write+0x183/0x2b0 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd80b57e719
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd80c3ae038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fd80b735f80 RCX: 00007fd80b57e719
RDX: 000000000000fecc RSI: 0000000020000100 RDI: 0000000000000005
RBP: 00007fd80b5f132e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd80b735f80 R15: 00007ffd276927f8
 </TASK>


Tested on:

commit:         3e5e6c99 Merge tag 'nfsd-6.12-3' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1689ab40580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4aec7739e14231a7
dashboard link: https://syzkaller.appspot.com/bug?extid=f51a2a34984e4d8888fd
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15091aa7980000