CVE-2024-49883
Vulnérabilité élevée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: ext4: aovid use-after-free in ext4_ext_insert_extent() As Ojaswin mentioned in Link, in ext4_ext_insert_extent(), if the path is reallocated in ext4_ext_create_new_leaf(), we'll use the stale path and cause UAF. Below is a sample trace with dummy values: ext4_ext_insert_extent path = *ppath = 2000 ext4_ext_create_new_leaf(ppath) ext4_find_extent(ppath) path = *ppath = 2000 if (depth > path[0].p_maxdepth) kfree(path = 2000); *ppath = path = NULL; path = kcalloc() = 3000 *ppath = 3000; return path; /* here path is still 2000, UAF! */ eh = path[depth].p_hdr ================================================================== BUG: KASAN: slab-use-after-free in ext4_ext_insert_extent+0x26d4/0x3330 Read of size 8 at addr ffff8881027bf7d0 by task kworker/u36:1/179 CPU: 3 UID: 0 PID: 179 Comm: kworker/u6:1 Not tainted 6.11.0-rc2-dirty #866 Call Trace: <TASK> ext4_ext_insert_extent+0x26d4/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 [...] Allocated by task 179: ext4_find_extent+0x81c/0x1f70 ext4_ext_map_blocks+0x146/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] Freed by task 179: kfree+0xcb/0x240 ext4_find_extent+0x7c0/0x1f70 ext4_ext_insert_extent+0xa26/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] ================================================================== So use *ppath to update the path to avoid the above problem.
Gravité et risque d'exploitation
CVE-2024-49883 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 0.28 %, ce qui la place devant 18.9 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions 10809df84a4d868db61af621bae3658494165279, <=6.1.*, 6.12, <=6.11.*, <9df59009dfc6d9fc1bd9ddf6c5ab6e56d6ed887a, 5.4.285, 0, <bfed082ce4b1ce6349b05c09a0fa4f3da35ecb1b, <=5.10.*, <=6.6.*, 6.6.55, 6.11.3, <beb7b66fb489041c50c6473100b383f7a51648fc, <=5.4.*, <=4.19.*, 6.1.113, <3.18, 4.19.323, <e17ebe4fdd7665c93ae9459ba40fcdfb76769ac1, <=*, <=5.15.*, <a164f3a432aae62ca23d03e6d926b122ee5b860d, 5.10.227, 6.10.14, <8162ee5d94b8c0351be0a9321be134872a7654a1, 5.15.168, <=6.10.*, <975ca06f3fd154c5f7742083e7b2574c57d1c0c3, 3.18, <51db04892a993cace63415be99848970a0f15ef2, <5e811066c5ab709b070659197dccfb80ab650ddd) 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/e17ebe4fdd7665c93ae9459ba40fcdfb76769ac1
- https://git.kernel.org/stable/c/975ca06f3fd154c5f7742083e7b2574c57d1c0c3
- https://git.kernel.org/stable/c/5e811066c5ab709b070659197dccfb80ab650ddd
- https://git.kernel.org/stable/c/9df59009dfc6d9fc1bd9ddf6c5ab6e56d6ed887a
- https://git.kernel.org/stable/c/51db04892a993cace63415be99848970a0f15ef2
- https://git.kernel.org/stable/c/8162ee5d94b8c0351be0a9321be134872a7654a1
- https://git.kernel.org/stable/c/beb7b66fb489041c50c6473100b383f7a51648fc
- https://git.kernel.org/stable/c/bfed082ce4b1ce6349b05c09a0fa4f3da35ecb1b
- https://git.kernel.org/stable/c/a164f3a432aae62ca23d03e6d926b122ee5b860d
