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CVE-2026-80560

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.8 · Élevée
EPSS 0.2%
Linux•Linux•Versions : <=6.1.*, ac689eb7f9d4e270d1365853b82eece669387e2c, <=6.12.*, 5.15.217, 0, 3.1, <=7.1.*, <32ef1b30ad736519f7a207bcc2986f3d4129d972, <212fc482ddd7f9ccdd74a05eab1cac849350dcd6, <89a91b30685c0493b0fa2b47d0ab41061a63069d, <=5.10.*, <=6.6.*, <3.1, <a88d688be8d7f03cbf927f2ab454ea9fa58d2979, 5.10.266, <=6.18.*, 6.1.184, 7.1.10, <bc2e24ba6e167ccf374a197457aa5640a802f429, <=*, <=5.15.*, 6.6.153, 6.12.105, 6.18.46, <cf1b5514ddf9df098ce7e3741fc9679fd85a4ec6, 7.2, <b4d73c3848bae9084fa8b9b2aa76d99a7d8eb17d, <cd8b43a71755c516f5c1f265a103438ae9ab15be

Description

In the Linux kernel, the following vulnerability has been resolved: openrisc: signal: do not restore privileged SR bits on sigreturn restore_sigcontext() copies the whole supervision register (SR) from the signal frame and only clears SPR_SR_SM before the value is reloaded into the hardware SR (through ESR and l.rfe) on the return to user space. All other SR bits are left under user control. An unprivileged task can thus return from a signal handler through a crafted sigframe that clears SPR_SR_DME. With the data MMU disabled the CPU performs no translation or protection on data accesses, so the task gains read and write access to arbitrary physical memory, a local privilege escalation. SPR_SR_IME, SPR_SR_SUMRA, SPR_SR_LEE, SPR_SR_EPH and the cache-enable bits are exposed the same way. The ptrace GPR regset already refuses any change to SR for exactly this reason. Restore only the arithmetic flag bits (F, CY, OV) from the signal frame and take every privileged control bit from the SR the kernel saved on signal entry. Verified with qemu-system-or1k -M or1k-sim: before this change an unprivileged PoC clears SPR_SR_DME in rt_sigreturn and writes a marker to physical address 0x03000000 (beyond the kernel's mem=32M); afterwards the same PoC receives SIGSEGV and physical memory is unchanged.

Gravité et risque d'exploitation

CVE-2026-80560 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 0.18 %, ce qui la place devant 6.7 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, ac689eb7f9d4e270d1365853b82eece669387e2c, <=6.12.*, 5.15.217, 0, 3.1, <=7.1.*, <32ef1b30ad736519f7a207bcc2986f3d4129d972, <212fc482ddd7f9ccdd74a05eab1cac849350dcd6, <89a91b30685c0493b0fa2b47d0ab41061a63069d, <=5.10.*, <=6.6.*, <3.1, <a88d688be8d7f03cbf927f2ab454ea9fa58d2979, 5.10.266, <=6.18.*, 6.1.184, 7.1.10, <bc2e24ba6e167ccf374a197457aa5640a802f429, <=*, <=5.15.*, 6.6.153, 6.12.105, 6.18.46, <cf1b5514ddf9df098ce7e3741fc9679fd85a4ec6, 7.2, <b4d73c3848bae9084fa8b9b2aa76d99a7d8eb17d, <cd8b43a71755c516f5c1f265a103438ae9ab15be) 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

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