CVE-2022-49769

Vulnérabilité non évaluée dans Linux (Linux)

CVSS 0.0 · Non évaluée
EPSS 0.2%
Linux•Linux•Versions : 5.4.225, <8b6534c9ae9dba5489703a19d8ba6c8f2cfa33c2, 2.6.19, 0, <670f8ce56dd0632dc29a0322e188cc73ce3c6b92, <d6b1e8ea6f3418c3b461ad5a35cdc93c996b2c87, <=4.9.*, <=5.10.*, <=4.14.*, <=6.0.*, <=5.4.*, 4.14.300, <2.6.19, <=4.19.*, b3b94faa5fe5968827ba0640ee9fba4b3e7f736e, 6.1, 4.19.267, <28275a7c84d21c55ab3282d897f284d8d527173c, <15c83fa0fd659dd9fbdc940a560b61236e876a80, <=*, <1ad197097343568066a8ffaa27ee7d0ae6d9f476, <=5.15.*, <5fa30be7ba81191b0a0c7239a89befc0c94286d5, 5.15.80, 5.10.156, <16670534c7cff1acd918a6a5ec751b14e7436b76, 4.9.334, 6.0.10

Description

In the Linux kernel, the following vulnerability has been resolved: gfs2: Check sb_bsize_shift after reading superblock Fuzzers like to scribble over sb_bsize_shift but in reality it's very unlikely that this field would be corrupted on its own. Nevertheless it should be checked to avoid the possibility of messy mount errors due to bad calculations. It's always a fixed value based on the block size so we can just check that it's the expected value. Tested with: mkfs.gfs2 -O -p lock_nolock /dev/vdb for i in 0 -1 64 65 32 33; do gfs2_edit -p sb field sb_bsize_shift $i /dev/vdb mount /dev/vdb /mnt/test && umount /mnt/test done Before this patch we get a withdraw after [ 76.413681] gfs2: fsid=loop0.0: fatal: invalid metadata block [ 76.413681] bh = 19 (type: exp=5, found=4) [ 76.413681] function = gfs2_meta_buffer, file = fs/gfs2/meta_io.c, line = 492 and with UBSAN configured we also get complaints like [ 76.373395] UBSAN: shift-out-of-bounds in fs/gfs2/ops_fstype.c:295:19 [ 76.373815] shift exponent 4294967287 is too large for 64-bit type 'long unsigned int' After the patch, these complaints don't appear, mount fails immediately and we get an explanation in dmesg.

Gravité et risque d'exploitation

CVE-2022-49769 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.22 %, ce qui la place devant 11.4 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions 5.4.225, <8b6534c9ae9dba5489703a19d8ba6c8f2cfa33c2, 2.6.19, 0, <670f8ce56dd0632dc29a0322e188cc73ce3c6b92, <d6b1e8ea6f3418c3b461ad5a35cdc93c996b2c87, <=4.9.*, <=5.10.*, <=4.14.*, <=6.0.*, <=5.4.*, 4.14.300, <2.6.19, <=4.19.*, b3b94faa5fe5968827ba0640ee9fba4b3e7f736e, 6.1, 4.19.267, <28275a7c84d21c55ab3282d897f284d8d527173c, <15c83fa0fd659dd9fbdc940a560b61236e876a80, <=*, <1ad197097343568066a8ffaa27ee7d0ae6d9f476, <=5.15.*, <5fa30be7ba81191b0a0c7239a89befc0c94286d5, 5.15.80, 5.10.156, <16670534c7cff1acd918a6a5ec751b14e7436b76, 4.9.334, 6.0.10) 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