[syzbot] kernel BUG in btrfs_drop_extents

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    c3eb11fbb826 Merge tag 'pci-v6.1-fixes-3' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15f07a05880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8d01b6e3197974dd
dashboard link: https://syzkaller.appspot.com/bug?extid=0b1fb6b0108c27419f9f
compiler:       Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=171a3f2d880000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17338b55880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d81ac029767f/disk-c3eb11fb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b68346b5b73c/vmlinux-c3eb11fb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/410a61724587/bzImage-c3eb11fb.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/272c7f0998ac/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0b1fb6b0108c27419f9f@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
kernel BUG at fs/btrfs/file.c:786!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 3625 Comm: syz-executor242 Not tainted 6.1.0-rc6-syzkaller-00015-gc3eb11fbb826 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:btrfs_drop_extents+0x3527/0x3550 fs/btrfs/file.c:786
Code: 00 48 8b 7c 24 48 e8 e8 9c 52 fe e9 85 fb ff ff e8 2e 84 fe fd 0f 0b e8 27 84 fe fd 0f 0b e8 20 84 fe fd 0f 0b e8 19 84 fe fd <0f> 0b e8 12 84 fe fd 0f 0b e8 0b 84 fe fd 0f 0b e8 04 84 fe fd 0f
RSP: 0018:ffffc90003afe000 EFLAGS: 00010293
RAX: ffffffff838c1457 RBX: 00000000fffffff4 RCX: ffff888077a657c0
RDX: 0000000000000000 RSI: 00000000fffffff4 RDI: 0000000000000000
RBP: ffffc90003afe390 R08: ffffffff838bfeb7 R09: ffffffff8381b3b2
R10: 0000000000000002 R11: ffff888077a657c0 R12: dffffc0000000000
R13: ffff888077829360 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000555556f703c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f199b878250 CR3: 0000000021698000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 cow_file_range_inline+0x41b/0x920 fs/btrfs/inode.c:434
 cow_file_range+0x391/0xfa0 fs/btrfs/inode.c:1219
 fallback_to_cow+0x47a/0x530 fs/btrfs/inode.c:1754
 run_delalloc_nocow+0x1249/0x14a0 fs/btrfs/inode.c:2161
 btrfs_run_delalloc_range+0x380/0x11a0 fs/btrfs/inode.c:2221
 writepage_delalloc+0x25e/0x540 fs/btrfs/extent_io.c:1968
 __extent_writepage+0x5d6/0x14d0 fs/btrfs/extent_io.c:2272
 extent_write_cache_pages+0x9e7/0x12d0 fs/btrfs/extent_io.c:3186
 extent_writepages+0x228/0x550 fs/btrfs/extent_io.c:3308
 do_writepages+0x3c3/0x680 mm/page-writeback.c:2469
 filemap_fdatawrite_wbc+0x11e/0x170 mm/filemap.c:388
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 filemap_fdatawrite_range+0x175/0x200 mm/filemap.c:439
 btrfs_fdatawrite_range fs/btrfs/file.c:4155 [inline]
 start_ordered_ops fs/btrfs/file.c:2041 [inline]
 btrfs_sync_file+0x39e/0x1140 fs/btrfs/file.c:2117
 generic_write_sync include/linux/fs.h:2883 [inline]
 btrfs_do_write_iter+0xcf2/0x1260 fs/btrfs/file.c:1990
 do_iter_write+0x6c2/0xc20 fs/read_write.c:861
 iter_file_splice_write+0x7fc/0xfc0 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0xe6/0x1c0 fs/splice.c:931
 splice_direct_to_actor+0x4e4/0xc00 fs/splice.c:886
 do_splice_direct+0x279/0x3d0 fs/splice.c:974
 do_sendfile+0x5fb/0xf80 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64+0x14f/0x1b0 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fd4bb0747e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 14 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd1c3b5eb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fd4bb0747e9
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 00007ffd1c3b5f00 R08: 0000000000000002 R09: aaaaaaaaaaaa0102
R10: 0001000000201005 R11: 0000000000000246 R12: 0000000000000007
R13: 00007fd4bb0ee7bc R14: 0000000000000003 R15: 0000000000000001
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:btrfs_drop_extents+0x3527/0x3550 fs/btrfs/file.c:786
Code: 00 48 8b 7c 24 48 e8 e8 9c 52 fe e9 85 fb ff ff e8 2e 84 fe fd 0f 0b e8 27 84 fe fd 0f 0b e8 20 84 fe fd 0f 0b e8 19 84 fe fd <0f> 0b e8 12 84 fe fd 0f 0b e8 0b 84 fe fd 0f 0b e8 04 84 fe fd 0f
RSP: 0018:ffffc90003afe000 EFLAGS: 00010293
RAX: ffffffff838c1457 RBX: 00000000fffffff4 RCX: ffff888077a657c0
RDX: 0000000000000000 RSI: 00000000fffffff4 RDI: 0000000000000000
RBP: ffffc90003afe390 R08: ffffffff838bfeb7 R09: ffffffff8381b3b2
R10: 0000000000000002 R11: ffff888077a657c0 R12: dffffc0000000000
R13: ffff888077829360 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000555556f703c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f4cf139900 CR3: 0000000021698000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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