WARNING in mark_buffer_dirty (2)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    81b6b964 Merge branch 'master' of git://git.kernel.org/pub..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14d35a96e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=333b76551307b2a0
dashboard link: https://syzkaller.appspot.com/bug?extid=60da3d6a696457b98553
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+60da3d6a696457b98553@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
WARNING: CPU: 1 PID: 8537 at fs/buffer.c:1088 mark_buffer_dirty+0x524/0x6c0  
fs/buffer.c:1088
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 8537 Comm: syz-executor.1 Not tainted 5.4.0-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS  
rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:mark_buffer_dirty+0x524/0x6c0 fs/buffer.c:1088
Code: 02 00 0f 85 9e 01 00 00 48 8b 3b be 04 00 00 00 e8 51 e7 fc ff e8 4c  
d2 a8 ff 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 3c d2 a8 ff <0f> 0b e9 2c fb  
ff ff e8 30 d2 a8 ff 0f 0b e9 53 fb ff ff e8 24 d2
RSP: 0000:ffff8880656d72f8 EFLAGS: 00010293
RAX: ffff88806dd68140 RBX: ffff888077cd9738 RCX: ffffffff81cc070e
RDX: 0000000000000000 RSI: ffffffff81cc0be4 RDI: 0000000000000001
RBP: ffff8880656d7320 R08: ffff88806dd68140 R09: ffffed100ef9b2e8
R10: ffffed100ef9b2e7 R11: ffff888077cd973f R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888070b421f8
 __ext4_handle_dirty_metadata+0x3f7/0x600 fs/ext4/ext4_jbd2.c:298
 ext4_free_blocks+0xeab/0x24d0 fs/ext4/mballoc.c:4940
 ext4_remove_blocks fs/ext4/extents.c:2678 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2831 [inline]
 ext4_ext_remove_space+0x2491/0x5650 fs/ext4/extents.c:3076
 ext4_ext_truncate+0x1b5/0x200 fs/ext4/extents.c:4599
 ext4_truncate+0xc6e/0x13c0 fs/ext4/inode.c:4511
 ext4_evict_inode+0x9d4/0x14e0 fs/ext4/inode.c:289
 evict+0x306/0x680 fs/inode.c:574
 iput_final fs/inode.c:1563 [inline]
 iput+0x55d/0x900 fs/inode.c:1589
 dentry_unlink_inode+0x2d9/0x400 fs/dcache.c:374
 __dentry_kill+0x38b/0x600 fs/dcache.c:579
 dentry_kill fs/dcache.c:698 [inline]
 dput+0x62f/0xe10 fs/dcache.c:859
 path_put+0x31/0x70 fs/namei.c:482
 free_fs_struct+0x25/0x70 fs/fs_struct.c:91
 exit_fs+0xf0/0x130 fs/fs_struct.c:108
 do_exit+0x8bd/0x2ef0 kernel/exit.c:793
 do_group_exit+0x135/0x360 kernel/exit.c:895
 get_signal+0x47c/0x24f0 kernel/signal.c:2734
 do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a759
Code: Bad RIP value.
RSP: 002b:00007faf7cbeacf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000071bf08 RCX: 000000000045a759
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000071bf08
RBP: 000000000071bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000071bf0c
R13: 00007ffc79ee6e9f R14: 00007faf7cbcb000 R15: 0000000000000003
Kernel Offset: disabled
Rebooting in 86400 seconds..


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