CVE-2024-57929

Description

In the Linux kernel, the following vulnerability has been resolved: dm array: fix releasing a faulty array block twice in dm_array_cursor_end When dm_bm_read_lock() fails due to locking or checksum errors, it releases the faulty block implicitly while leaving an invalid output pointer behind. The caller of dm_bm_read_lock() should not operate on this invalid dm_block pointer, or it will lead to undefined result. For example, the dm_array_cursor incorrectly caches the invalid pointer on reading a faulty array block, causing a double release in dm_array_cursor_end(), then hitting the BUG_ON in dm-bufio cache_put(). Reproduce steps: 1. initialize a cache device dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 65536 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc $262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" 2. wipe the second array block offline dmsteup remove cache cmeta cdata corig mapping_root=$(dd if=/dev/sdc bs=1c count=8 skip=192 \ 2>/dev/null | hexdump -e '1/8 "%u\n"') ablock=$(dd if=/dev/sdc bs=1c count=8 skip=$((4096*mapping_root+2056)) \ 2>/dev/null | hexdump -e '1/8 "%u\n"') dd if=/dev/zero of=/dev/sdc bs=4k count=1 seek=$ablock 3. try reopen the cache device dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 65536 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc $262144" dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" Kernel logs: (snip) device-mapper: array: array_block_check failed: blocknr 0 != wanted 10 device-mapper: block manager: array validator check failed for block 10 device-mapper: array: get_ablock failed device-mapper: cache metadata: dm_array_cursor_next for mapping failed ------------[ cut here ]------------ kernel BUG at drivers/md/dm-bufio.c:638! Fix by setting the cached block pointer to NULL on errors. In addition to the reproducer described above, this fix can be verified using the "array_cursor/damaged" test in dm-unit: dm-unit run /pdata/array_cursor/damaged --kernel-dir <KERNEL_DIR>

Gravité et risque d'exploitation

CVE-2024-57929 obtient un score CVSS de 7.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.26 %, ce qui la place devant 16.7 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions 6.13, <=6.1.*, <=6.12.*, <017c4470bff53585370028fec9341247bad358ff, 0, 5.10.234, <6002bec5354f86d1a2df21468f68e3ec03ede9da, <=5.10.*, <=6.6.*, 5.4.290, <e477021d252c007f0c6d45b5d13d341efed03979, 6.6.72, <f2893c0804d86230ffb8f1c8703fdbb18648abc8, fdd1315aa5f022fe6574efdc2d9535f75a0ee255, 5.15.177, <=5.4.*, <738994872d77e189b2d13c501a1d145e95d98f46, <4.9, <9c7c03d0e926762adf3a3a0ba86156fb5e19538b, <=*, 4.9, <=5.15.*, 6.12.10, <fc1ef07c3522e257e32702954f265debbcb096a7, 6.1.125) est présent sur votre parc.
• Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
• À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
• Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

• https://git.kernel.org/stable/c/9c7c03d0e926762adf3a3a0ba86156fb5e19538b
• https://git.kernel.org/stable/c/fc1ef07c3522e257e32702954f265debbcb096a7
• https://git.kernel.org/stable/c/738994872d77e189b2d13c501a1d145e95d98f46
• https://git.kernel.org/stable/c/e477021d252c007f0c6d45b5d13d341efed03979
• https://git.kernel.org/stable/c/6002bec5354f86d1a2df21468f68e3ec03ede9da
• https://git.kernel.org/stable/c/017c4470bff53585370028fec9341247bad358ff
• https://git.kernel.org/stable/c/f2893c0804d86230ffb8f1c8703fdbb18648abc8