CVE-2023-53339 btrfs: fix BUG_ON condition in btrfs_cancel_balance
A race condition in the btrfs filesystem can cause a kernel panic, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-53339?
CVE-2023-53339 is a medium-severity vulnerability in Linux kernel, published on 17 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix BUG_ON condition in btrfs_cancel_balance
Pausing and canceling balance can race to interrupt balance lead to BUG_ON panic in btrfs_cancel_balance. The BUG_ON condition in btrfs_cancel_balance does not take this race scenario into account.
However, the race condition has no other side effects. We can fix that.
Reproducing it with panic trace like this:
kernel BUG at fs/btrfs/volumes.c:4618! RIP: 0010:btrfs_cancel_balance+0x5cf/0x6a0 Call Trace: <TASK> ? do_nanosleep+0x60/0x120 ? hrtimer_nanosleep+0xb7/0x1a0 ? sched_core_clone_cookie+0x70/0x70 btrfs_ioctl_balance_ctl+0x55/0x70 btrfs_ioctl+0xa46/0xd20 __x64_sys_ioctl+0x7d/0xa0 do_syscall_64+0x38/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Race scenario as follows: > mutex_unlock(&fs_info->balance_mutex); > -------------------- > .......issue pause and cancel req in another thread > -------------------- > ret = __btrfs_balance(fs_info); > > mutex_lock(&fs_info->balance_mutex); > if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req)) { > btrfs_info(fs_info, "balance: paused"); > btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED); > }
Weakness: CWE-617
Which versions are affected by CVE-2023-53339?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53339?
Apply the vendor's patch.
Is CVE-2023-53339 being exploited?
There is no known exploitation of CVE-2023-53339 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53339, DEBIAN-CVE-2023-53339, GHSA-7gmh-9h47-r2x3, UBUNTU-CVE-2023-53339.