CVE-2026-53060

Summary

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>

Affected Software

Weaknesses

References

• 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

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