[syzbot] [btrfs?] WARNING in btrfs_add_to_free_space_tree (2)
From: syzbot
Date: Sun Aug 23 2026 - 01:23:50 EST
Hello,
syzbot found the following issue on:
HEAD commit: 818bebeb63dd drm/xe: Don't hand out the flat CCS storage a..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14f18415580000
kernel config: https://syzkaller.appspot.com/x/.config?x=3c35c7e43de75adb
dashboard link: https://syzkaller.appspot.com/bug?extid=554a2e08e4abc56984a9
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-818bebeb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9adea981957f/vmlinux-818bebeb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6676075cd03e/bzImage-818bebeb.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+554a2e08e4abc56984a9@xxxxxxxxxxxxxxxxxxxxxxxxx
loop0: detected capacity change from 0 to 32768
BTRFS: device fsid 395ef67a-297e-477c-816d-cd80a5b93e5d devid 1 transid 8 /dev/loop0 (7:0) scanned by syz.0.0 (5311)
BTRFS info (device loop0): first mount of filesystem 395ef67a-297e-477c-816d-cd80a5b93e5d
BTRFS info (device loop0): using sha256 checksum algorithm
BTRFS info (device loop0): rebuilding free space tree
BTRFS info (device loop0): enabling ssd optimizations
BTRFS info (device loop0): using spread ssd allocation scheme
BTRFS info (device loop0): turning on async discard
BTRFS info (device loop0): enabling free space tree
BTRFS info (device loop0): force clearing of disk cache
loop0: detected capacity change from 32768 to 32767
------------[ cut here ]------------
btrfs_abort_should_print_stack(__error)
WARNING: fs/btrfs/free-space-tree.c:1050 at btrfs_add_to_free_space_tree+0x4e1/0x5b0 fs/btrfs/free-space-tree.c:1050, CPU#0: syz.0.0/5311
Modules linked in:
CPU: 0 UID: 0 PID: 5311 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:btrfs_add_to_free_space_tree+0x4e1/0x5b0 fs/btrfs/free-space-tree.c:1050
Code: e2 74 1a 41 83 fd fb 74 0d 41 83 fd f4 75 15 e8 65 ba 8c fd eb 17 e8 5e ba 8c fd eb 10 e8 57 ba 8c fd eb 09 e8 50 ba 8c fd 90 <0f> 0b 90 44 89 e9 f7 d9 4c 8b 24 24 e9 95 fe ff ff 89 d9 80 e1 07
RSP: 0018:ffffc9000f29f3f0 EFLAGS: 00010287
RAX: ffffffff843a7a70 RBX: ffff888051a74001 RCX: 0000000000100000
RDX: ffffc9000e901000 RSI: 00000000000038d7 RDI: 00000000000038d8
RBP: ffff88801276a5e0 R08: ffff88801f99cb00 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000002 R12: ffff8880138e2db8
R13: 00000000ffffffe4 R14: ffff88801fc77630 R15: 1ffff110024ed4c8
FS: 00007f00ab5f36c0(0000) GS:ffff88808c30a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f00ab5b0fe8 CR3: 0000000043b27000 CR4: 0000000000352ef0
Call Trace:
<TASK>
do_free_extent_accounting fs/btrfs/extent-tree.c:3191 [inline]
__btrfs_free_extent+0x1461/0x39c0 fs/btrfs/extent-tree.c:3558
run_delayed_tree_ref fs/btrfs/extent-tree.c:1824 [inline]
run_one_delayed_ref fs/btrfs/extent-tree.c:1851 [inline]
btrfs_run_delayed_refs_for_head fs/btrfs/extent-tree.c:2058 [inline]
__btrfs_run_delayed_refs+0x166c/0x43b0 fs/btrfs/extent-tree.c:2134
btrfs_run_delayed_refs+0xdc/0x2a0 fs/btrfs/extent-tree.c:2246
btrfs_commit_transaction+0x28a/0x30b0 fs/btrfs/transaction.c:2256
btrfs_quota_enable+0x10ff/0x1e20 fs/btrfs/qgroup.c:1237
btrfs_ioctl_quota_ctl+0x186/0x1f0 fs/btrfs/ioctl.c:3566
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f00aa79e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f00ab5f2fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f00aaa25fa0 RCX: 00007f00aa79e0d9
RDX: 00002000000000c0 RSI: 00000000c0109428 RDI: 0000000000000003
RBP: 00007f00aa835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f00aaa26038 R14: 00007f00aaa25fa0 R15: 00007ffd0ce801f8
</TASK>
---
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