CVE-2026-52941
Vulnérabilité non évaluée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: net/smc: avoid NULL deref of conn->lnk in smc_msg_event tracepoint The smc_msg_event tracepoint class, shared by smc_tx_sendmsg and smc_rx_recvmsg, unconditionally dereferences smc->conn.lnk: __string(name, smc->conn.lnk->ibname) conn->lnk is only set for SMC-R; for SMC-D it is NULL. Other code on these paths already handles this (e.g. !conn->lnk in SMC_STAT_RMB_TX_SIZE_SMALL()). With the tracepoint enabled, the first sendmsg()/recvmsg() on an SMC-D socket crashes: Oops: general protection fault, probably for non-canonical address KASAN: null-ptr-deref in range [...] RIP: 0010:strlen+0x1e/0xa0 Call Trace: trace_event_raw_event_smc_msg_event (net/smc/smc_tracepoint.h:44) smc_rx_recvmsg (net/smc/smc_rx.c:515) smc_recvmsg (net/smc/af_smc.c:2859) __sys_recvfrom (net/socket.c:2315) __x64_sys_recvfrom (net/socket.c:2326) do_syscall_64 The faulting address 0x3e0 is offsetof(struct smc_link, ibname), confirming the NULL ->lnk deref. Enabling the tracepoint requires root, but the trigger itself is unprivileged: socket(AF_SMC, ...) has no capability check, and SMC-D negotiation needs no admin step on s390 or on x86 with the loopback ISM device loaded. Log an empty device name for SMC-D instead of dereferencing NULL.
Gravité et risque d'exploitation
CVE-2026-52941 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 0.12 %, ce qui la place devant 1.6 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <=6.1.*, <=7.0.*, <=6.12.*, 5.16, <b706d6d76a2a2793fe5ad0fbc2a75b6a460094ef, <68200112534bb2acd1d7117dc2d5c124868d866d, 0, <d2ea0b8aef8746e147602eac87ca8538f4bc7e66, 6.12.92, 6.6.142, <=6.6.*, 6.1.175, <561cf66fa9b6c86dfe4e687d2d1aeaaa6739917f, <720c76b930c52cd58f50eb6b10569d03dccc7959, <7bf563badd37cb796df5477d2b78bb64148a1268, 6.18.34, <5.16, 7.1, <=6.18.*, 7.0.11, aff3083f10bff7a37eaa2b4e6bc5fb627ddd5f84, <=*) 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/68200112534bb2acd1d7117dc2d5c124868d866d
- https://git.kernel.org/stable/c/720c76b930c52cd58f50eb6b10569d03dccc7959
- https://git.kernel.org/stable/c/b706d6d76a2a2793fe5ad0fbc2a75b6a460094ef
- https://git.kernel.org/stable/c/d2ea0b8aef8746e147602eac87ca8538f4bc7e66
- https://git.kernel.org/stable/c/561cf66fa9b6c86dfe4e687d2d1aeaaa6739917f
- https://git.kernel.org/stable/c/7bf563badd37cb796df5477d2b78bb64148a1268
