Heimdall Security Logo

CVE-2022-48731

Vulnérabilité moyenne dans Linux (Linux)

CVSS 5.5 · Moyenne
EPSS 0.2%
Linux•Linux•Versions : <a5389c80992f0001ee505838fe6a8b20897ce96e, 0, <cebb0aceb21ad91429617a40e3a17444fabf1529, <d3533ee20e9a0e2e8f60384da7450d43d1c63d1a, <352715593e81b917ce1b321e794549815b850134, <=5.10.*, <=5.4.*, 5.4.178, 4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378, <c10a0f877fe007021d70f9cada240f42adc2b5db, 5.10.99, <=5.16.*, <=*, <4.14, <=5.15.*, 5.17, 5.15.22, 4.14, 5.16.8

Description

In the Linux kernel, the following vulnerability has been resolved: mm/kmemleak: avoid scanning potential huge holes When using devm_request_free_mem_region() and devm_memremap_pages() to add ZONE_DEVICE memory, if requested free mem region's end pfn were huge(e.g., 0x400000000), the node_end_pfn() will be also huge (see move_pfn_range_to_zone()). Thus it creates a huge hole between node_start_pfn() and node_end_pfn(). We found on some AMD APUs, amdkfd requested such a free mem region and created a huge hole. In such a case, following code snippet was just doing busy test_bit() looping on the huge hole. for (pfn = start_pfn; pfn < end_pfn; pfn++) { struct page *page = pfn_to_online_page(pfn); if (!page) continue; ... } So we got a soft lockup: watchdog: BUG: soft lockup - CPU#6 stuck for 26s! [bash:1221] CPU: 6 PID: 1221 Comm: bash Not tainted 5.15.0-custom #1 RIP: 0010:pfn_to_online_page+0x5/0xd0 Call Trace: ? kmemleak_scan+0x16a/0x440 kmemleak_write+0x306/0x3a0 ? common_file_perm+0x72/0x170 full_proxy_write+0x5c/0x90 vfs_write+0xb9/0x260 ksys_write+0x67/0xe0 __x64_sys_write+0x1a/0x20 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae I did some tests with the patch. (1) amdgpu module unloaded before the patch: real 0m0.976s user 0m0.000s sys 0m0.968s after the patch: real 0m0.981s user 0m0.000s sys 0m0.973s (2) amdgpu module loaded before the patch: real 0m35.365s user 0m0.000s sys 0m35.354s after the patch: real 0m1.049s user 0m0.000s sys 0m1.042s

Gravité et risque d'exploitation

CVE-2022-48731 obtient un score CVSS de 5.5/10, soit une gravité moyenne. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.17 %, ce qui la place devant 5.7 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <a5389c80992f0001ee505838fe6a8b20897ce96e, 0, <cebb0aceb21ad91429617a40e3a17444fabf1529, <d3533ee20e9a0e2e8f60384da7450d43d1c63d1a, <352715593e81b917ce1b321e794549815b850134, <=5.10.*, <=5.4.*, 5.4.178, 4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378, <c10a0f877fe007021d70f9cada240f42adc2b5db, 5.10.99, <=5.16.*, <=*, <4.14, <=5.15.*, 5.17, 5.15.22, 4.14, 5.16.8) 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

Rechercher une autre CVE