kernel BUG in btrfs_free_tree_block

Status: auto-obsoleted due to no activity on 2025/09/21 10:08
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+df51e4b53e70a282bdc6@syzkaller.appspotmail.com
First crash: 1136d, last: 536d
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2023/07/03 upstream (ToT) a901a3568fd2 C [report] WARNING in btrfs_space_info_update_bytes_may_use
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 kernel BUG in btrfs_free_tree_block (2) -1 1 14d 14d 0/3 upstream: reported on 2026/07/29 07:23
upstream kernel BUG in btrfs_free_tree_block btrfs -1 syz, C error 150 729d 1415d 27/29 fixed on 2024/08/14 03:44
linux-6.1 kernel BUG in btrfs_free_tree_block origin:upstream missing-backport -1 syz, C inconclusive 20 13d 1095d 0/3 upstream: reported C repro on 2023/08/12 21:44
▶ ▼ Last patch testing requests (5)
Created Duration User Patch Repo Result
2025/09/21 09:49 18m retest repro linux-5.15.y no crash log
2025/07/12 17:43 11m retest repro linux-5.15.y report log
2025/05/03 12:43 15m retest repro linux-5.15.y report log
2025/02/21 16:04 15m retest repro linux-5.15.y report log
2024/12/13 13:43 23m retest repro linux-5.15.y report log

Sample crash report:
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
------------[ cut here ]------------
kernel BUG at fs/btrfs/extent-tree.c:3295!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4805 Comm: syz.4.137 Not tainted 5.15.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : btrfs_free_tree_block+0xc08/0xdcc fs/btrfs/extent-tree.c:3295
lr : btrfs_free_tree_block+0xc08/0xdcc fs/btrfs/extent-tree.c:3295
sp : ffff800020836d60
x29: ffff800020836e80 x28: ffff0000dbf58000 x27: ffff800020836df0
x26: 00000000fffffff4 x25: 0000000000000001 x24: ffff0000c7c8b670
x23: 0000000000000005 x22: ffff0000dbf58000 x21: ffff0000c7c8b550
x20: 0000000000000001 x19: dfff800000000000 x18: 0000000000000001
x17: 0000000000000000 x16: ffff800011b4efd4 x15: 00000000ffffffff
x14: ffff0000d0f051c0 x13: 0000000000000001 x12: 0000000000000001
x11: 0000000000000000 x10: 0000000000000000 x9 : ffff0000d0f051c0
x8 : ffff80000a0756e0 x7 : 0000000000000000 x6 : 0000000000000001
x5 : ffff8000208360b8 x4 : 00000000000000a8 x3 : 0000000000000068
x2 : 0000000000000000 x1 : 00000000fffffff4 x0 : 0000000000000000
Call trace:
 btrfs_free_tree_block+0xc08/0xdcc fs/btrfs/extent-tree.c:3295
 btrfs_force_cow_block+0xc88/0x19b8 fs/btrfs/ctree.c:480
 btrfs_cow_block+0x308/0x6a0 fs/btrfs/ctree.c:598
 btrfs_search_slot+0xb50/0x24f8
 btrfs_insert_empty_items+0x1e4/0x2ac fs/btrfs/ctree.c:4012
 btrfs_new_inode+0x8d0/0x18a8 fs/btrfs/inode.c:6655
 btrfs_create+0x28c/0x56c fs/btrfs/inode.c:6908
 lookup_open fs/namei.c:3462 [inline]
 open_last_lookups fs/namei.c:3532 [inline]
 path_openat+0xf18/0x26cc fs/namei.c:3739
 do_filp_open+0x1a8/0x3b4 fs/namei.c:3769
 do_sys_openat2+0x128/0x3e0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1280
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: c80a7e69 35ffffaa 17ffff2b 97913b73 (d4210000) 
---[ end trace 9e5492a0d923b495 ]---

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/26 18:11 linux-5.15.y 003148680b79 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 kernel BUG in btrfs_free_tree_block
2023/09/17 09:06 linux-5.15.y aff03380bda4 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 kernel BUG in btrfs_free_tree_block
2023/07/03 03:55 linux-5.15.y 4af60700a60c bfc47836 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 kernel BUG in btrfs_free_tree_block
* Struck through repros no longer work on HEAD.