In the Linux kernel, the following vulnerability has been resolved:
btrfs: handle case when repair happens with dev-replace
[BUG]
There is a bug report that a BUG_ON() in btrfs_repair_io_failure()
(originally repair_io_failure() in v6.0 kernel) got triggered when
replacing a unreliable disk:
BTRFS warning (device sda1): csum failed root 257 ino 2397453 off 39624704 csum 0xb0d18c75 expected csum 0x4dae9c5e mirror 3
kernel BUG at fs/btrfs/extent_io.c:2380!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 9 PID: 3614331 Comm: kworker/u257:2 Tainted: G OE 6.0.0-5-amd64 #1 Debian 6.0.10-2
Hardware name: Micro-Star International Co., Ltd. MS-7C60/TRX40 PRO WIFI (MS-7C60), BIOS 2.70 07/01/2021
Workqueue: btrfs-endio btrfs_end_bio_work [btrfs]
RIP: 0010:repair_io_failure+0x24a/0x260 [btrfs]
Call Trace:
<TASK>
clean_io_failure+0x14d/0x180 [btrfs]
end_bio_extent_readpage+0x412/0x6e0 [btrfs]
? __switch_to+0x106/0x420
process_one_work+0x1c7/0x380
worker_thread+0x4d/0x380
? rescuer_thread+0x3a0/0x3a0
kthread+0xe9/0x110
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x22/0x30
[CAUSE]
Before the BUG_ON(), we got some read errors from the replace target
first, note the mirror number (3, which is beyond RAID1 duplication,
thus it's read from the replace target device).
Then at the BUG_ON() location, we are trying to writeback the repaired
sectors back the failed device.
The check looks like this:
ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
&map_length, &bioc, mirror_num);
if (ret)
goto out_counter_dec;
BUG_ON(mirror_num != bioc->mirror_num);
But inside btrfs_map_block(), we can modify bioc->mirror_num especially
for dev-replace:
if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
!need_full_stripe(op) && dev_replace->tgtdev != NULL) {
ret = get_extra_mirror_from_replace(fs_info, logical, *length,
dev_replace->srcdev->devid,
&mirror_num,
&physical_to_patch_in_first_stripe);
patch_the_first_stripe_for_dev_replace = 1;
}
Thus if we're repairing the replace target device, we're going to
trigger that BUG_ON().
But in reality, the read failure from the replace target device may be
that, our replace hasn't reached the range we're reading, thus we're
reading garbage, but with replace running, the range would be properly
filled later.
Thus in that case, we don't need to do anything but let the replace
routine to handle it.
[FIX]
Instead of a BUG_ON(), just skip the repair if we're repairing the
device replace target device.
Metrics
Affected Vendors & Products
References
History
Tue, 30 Dec 2025 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: btrfs: handle case when repair happens with dev-replace [BUG] There is a bug report that a BUG_ON() in btrfs_repair_io_failure() (originally repair_io_failure() in v6.0 kernel) got triggered when replacing a unreliable disk: BTRFS warning (device sda1): csum failed root 257 ino 2397453 off 39624704 csum 0xb0d18c75 expected csum 0x4dae9c5e mirror 3 kernel BUG at fs/btrfs/extent_io.c:2380! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 9 PID: 3614331 Comm: kworker/u257:2 Tainted: G OE 6.0.0-5-amd64 #1 Debian 6.0.10-2 Hardware name: Micro-Star International Co., Ltd. MS-7C60/TRX40 PRO WIFI (MS-7C60), BIOS 2.70 07/01/2021 Workqueue: btrfs-endio btrfs_end_bio_work [btrfs] RIP: 0010:repair_io_failure+0x24a/0x260 [btrfs] Call Trace: <TASK> clean_io_failure+0x14d/0x180 [btrfs] end_bio_extent_readpage+0x412/0x6e0 [btrfs] ? __switch_to+0x106/0x420 process_one_work+0x1c7/0x380 worker_thread+0x4d/0x380 ? rescuer_thread+0x3a0/0x3a0 kthread+0xe9/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30 [CAUSE] Before the BUG_ON(), we got some read errors from the replace target first, note the mirror number (3, which is beyond RAID1 duplication, thus it's read from the replace target device). Then at the BUG_ON() location, we are trying to writeback the repaired sectors back the failed device. The check looks like this: ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical, &map_length, &bioc, mirror_num); if (ret) goto out_counter_dec; BUG_ON(mirror_num != bioc->mirror_num); But inside btrfs_map_block(), we can modify bioc->mirror_num especially for dev-replace: if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 && !need_full_stripe(op) && dev_replace->tgtdev != NULL) { ret = get_extra_mirror_from_replace(fs_info, logical, *length, dev_replace->srcdev->devid, &mirror_num, &physical_to_patch_in_first_stripe); patch_the_first_stripe_for_dev_replace = 1; } Thus if we're repairing the replace target device, we're going to trigger that BUG_ON(). But in reality, the read failure from the replace target device may be that, our replace hasn't reached the range we're reading, thus we're reading garbage, but with replace running, the range would be properly filled later. Thus in that case, we don't need to do anything but let the replace routine to handle it. [FIX] Instead of a BUG_ON(), just skip the repair if we're repairing the device replace target device. | |
| Title | btrfs: handle case when repair happens with dev-replace | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-12-30T12:08:51.727Z
Reserved: 2025-12-30T12:06:44.497Z
Link: CVE-2023-54180
No data.
Status : Received
Published: 2025-12-30T13:16:05.933
Modified: 2025-12-30T13:16:05.933
Link: CVE-2023-54180
No data.
OpenCVE Enrichment
No data.