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CVE-2026-80876

Vulnérabilité non évaluée dans Linux (Linux)

CVSS 0.0 · Non évaluée
EPSS 0.2%
Linux•Linux•Versions : <=6.1.*, 7.1.5, 6.18.40, <=6.12.*, <24c3fa71f9947b0e1f3b954db1b769b44140192e, <3a63a11897c7ba32d1be7a3fdbc48a8b01cf4992, <cfada73fabe2ccc06ec77fe2ceaa088689213326, 0, <7c9f0ccf9f04142458d2ac3d39414f4acae242f0, <=7.1.*, <2.6.34, <c37e0a4b79a6bbb96ce5ffe279d7c001e20529e0, 6.1.178, <ec5e96aee75d27779b9a860307679f13f33adb0c, <=5.10.*, <=6.6.*, 6.12.97, 2.6.34, <=6.18.*, 5.15.212, 6.6.145, 5.10.261, <14057268e79654c3e8ea2c9b5204cb9644b2964d, 2271048d1b3b0aabf83d25b29c20646dcabedc05, <=*, <=5.15.*, <dbcb8635b1eb7603818591cf745c7b1d714f7ac6, 7.2

Description

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix event length with forced 8-byte alignment When RB_FORCE_8BYTE_ALIGNMENT is true, rb_calculate_event_length() reserves the space of event->array[0] for placing the data length and rb_update_event() stores the data length in event->array[0] accordingly. As a result the whole event length will add extra 4 bytes for sizeof(event.array[0]) unconditionally. But ring_buffer_event_length() only subtracts the sizeof(event->array[0]) for events larger than RB_MAX_SMALL_DATA + sizeof(event->array[0]). As a result, small events on architectures with RB_FORCE_8BYTE_ALIGNMENT=true report a data length that is 4 bytes larger than expected. To fix it, add the RB_FORCE_8BYTE_ALIGNMENT as a condition to subtract the size of that length field whenever RB_FORCE_8BYTE_ALIGNMENT is true. This issue is observed in a riscv64 kernel with CONFIG_HAVE_64BIT_ALIGNED_ACCESS set to y, when we run ftrace selftest trace_marker_raw.tc, we get the weird log: for cases where the id is 1..100, the number of data field is 8*N, but once id exceeds 100, the number of data field becomes 8*N+4: # 1 buf: 58 00 00 00 80 5e d1 63 (number of data field is 8*1) ... # a buf: 58 ... (number of data field is 8*2) ... # 64 buf: 58 ... (number of data field is 8*13) # 65 buf: 58 ... (number of data field is 8*13+4) After applying this change, the number of data field keeps being 8*N+4 consistently.

Gravité et risque d'exploitation

CVE-2026-80876 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 11.6 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, 7.1.5, 6.18.40, <=6.12.*, <24c3fa71f9947b0e1f3b954db1b769b44140192e, <3a63a11897c7ba32d1be7a3fdbc48a8b01cf4992, <cfada73fabe2ccc06ec77fe2ceaa088689213326, 0, <7c9f0ccf9f04142458d2ac3d39414f4acae242f0, <=7.1.*, <2.6.34, <c37e0a4b79a6bbb96ce5ffe279d7c001e20529e0, 6.1.178, <ec5e96aee75d27779b9a860307679f13f33adb0c, <=5.10.*, <=6.6.*, 6.12.97, 2.6.34, <=6.18.*, 5.15.212, 6.6.145, 5.10.261, <14057268e79654c3e8ea2c9b5204cb9644b2964d, 2271048d1b3b0aabf83d25b29c20646dcabedc05, <=*, <=5.15.*, <dbcb8635b1eb7603818591cf745c7b1d714f7ac6, 7.2) 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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