CVE-2026-53060
Description
In the Linux kernel, the following vulnerability has been resolved:
dm cache metadata: fix memory leak on metadata abort retry
When failing to acquire the root_lock in dm_cache_metadata_abort because
the block_manager is read-only, the temporary block_manager created
outside the root_lock is not properly released, causing a memory leak.
Reproduce steps:
This can be reproduced by reloading a new table while the metadata
is read-only. While the second call to dm_cache_metadata_abort is
caused by lack of support for table preload in dm-cache, mentioned
in commit 9b1cc9f251af ("dm cache: share cache-metadata object across
inactive and active DM tables"), it exposes the memory leak in
dm_cache_metadata_abort when the function is called multiple times.
Specifically, dm-cache fails to sync the new cache object's mode during
preresume, creating the reproducer condition.
This issue could also occur through concurrent metadata_operation_failed
calls due to races in cache mode updates, but the table preload scenario
below provides a reliable reproducer.
1. Create a cache device with some faulty trailing metadata blocks
dmsetup create cmeta <<EOF
0 200 linear /dev/sdc 0
200 7992 error
EOF
dmsetup create cdata --table "0 131072 linear /dev/sdc 8192"
dmsetup create corig --table "0 262144 linear /dev/sdc 262144"
dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct
dmsetup create cache --table "0 131072 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 1 writethrough smq 0"
2. Suspend and resume the cache to start a new metadata transaction and
trigger metadata io errors on the next metadata commit.
dmsetup suspend cache
dmsetup resume cache
3. Write to the cache device to update metadata
fio --filename=/dev/mapper/cache --name test --rw=randwrite --bs=4k \
--randrepeat=0 --direct=1 --size 64k
4. Preload the same table
dmsetup reload cache --table "$(dmsetup table cache)"
5. Resume the new table. This triggers the memory leak.
dmsetup suspend cache
dmsetup resume cache
kmemleak logs:
<snip>
unreferenced object 0xffff8880080c2010 (size 16):
comm "dmsetup", pid 132, jiffies 4294982580
hex dump (first 16 bytes):
00 38 b9 07 80 88 ff ff 6a 6b 6b 6b 6b 6b 6b a5 ...
backtrace (crc 3118f31c):
kmemleak_alloc+0x28/0x40
__kmalloc_cache_noprof+0x3d9/0x510
dm_block_manager_create+0x51/0x140
dm_cache_metadata_abort+0x85/0x320
metadata_operation_failed+0x103/0x1e0
cache_preresume+0xacd/0xe70
dm_table_resume_targets+0xd3/0x320
__dm_resume+0x1b/0xf0
dm_resume+0x127/0x170
<snip>
Metadata
Severity & Metrics
No CVSS data available.
Affected products (2)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| Linux | Linux | — | b45e77b79215405bd039a690f5b06cc03e8ed27d < 14f60e957f34f95a626caec76a8fae88cf4c397f, 28d307f380df88a598bc0186d527462902d9bda1 < 6b97cc7a42905755c56bbddc33aa8b792205caee, f74b7c5a85e22cd9091845e0d62a1dd89d0f855f < d1a79620c419a0af1911f99c873014b30740e303, 352b837a5541690d4f843819028cf2b8be83d424 < 15c30997dca681f90dbf2d45ee629c1828bf0c0d … |
| Linux | Linux | — | 6.2, 0 < 6.2, 5.10.258 ≤ 5.10.*, 5.15.209 ≤ 5.15.* … |
References (8)
- https://git.kernel.org/stable/c/14f60e957f34f95a626caec76a8fae88cf4c397f
- https://git.kernel.org/stable/c/6b97cc7a42905755c56bbddc33aa8b792205caee
- https://git.kernel.org/stable/c/d1a79620c419a0af1911f99c873014b30740e303
- https://git.kernel.org/stable/c/15c30997dca681f90dbf2d45ee629c1828bf0c0d
- https://git.kernel.org/stable/c/b0bd35535bdb6f58505f3a30ee5793986943997a
- https://git.kernel.org/stable/c/322a3b70368d49e39591fe9fc6c07d262128b05f
- https://git.kernel.org/stable/c/4311ca59a1891d33c4c8b7946f98c34f167fe833
- https://git.kernel.org/stable/c/044ca491d4086dc5bf233e9fcb71db52df32f633