CVE-2026-72014
Publiée le 2026-08-15 · Dernière modification le 2026-10-19
Les serveurs Linux utilisant Distributed Replicated Block Device (DRBD) dans une configuration sans disque (diskless) ou d'équilibrage de lecture (read-balancing) sont concernés. Un nœud pair malveillant ou compromis sur le réseau peut envoyer des paquets de données spécifiquement conçus pour déclencher une erreur de corruption de mémoire dans le noyau, ce qui peut entraîner un plantage complet du système ou l'exécution à distance de code non autorisé. Cette attaque est facile à exécuter car elle ne nécessite ni authentification ni interaction de l'utilisateur, seulement un accès réseau au service DRBD.
DÉTAIL DU VECTEUR CVSS
RÉFÉRENCES
Description officielle du NVD (en anglais)
In the Linux kernel, the following vulnerability has been resolved: drbd: reject data replies with an out-of-range payload size recv_dless_read() receives a P_DATA_REPLY from a peer into the bio of an outstanding read request. The peer-supplied payload length reaches it as the signed int data_size, and two peer-controlled inputs can make it negative. With a negotiated data-integrity-alg the digest length is subtracted first, so a reply whose payload is smaller than the digest underflows data_size. With no integrity algorithm (the default) data_size is assigned from the unsigned h95/h100 wire length and drbdd() never bounds it for a payload-carrying command, so a length above INT_MAX casts it negative; this path needs no non-default feature. The bio receive loop then computes expect = min_t(int, data_size, bv_len), which is negative, and drbd_recv_all_warn(mapped, expect) receives with a size_t of SIZE_MAX into the first mapped page. The sibling receive path read_in_block() is not affected: it uses an unsigned size and rejects it against DRBD_MAX_BIO_SIZE before receiving. Reject a data reply whose size is negative after the optional digest subtraction, covering both triggers. Impact: a malicious or man-in-the-middle DRBD peer copies attacker-chosen bytes past a bio page in the receiver, corrupting kernel memory. A node that reads from its peer (a diskless node, or read-balancing to the peer) is exposed in the default configuration; data-integrity-alg is not required.