CVE-2026-89971
Vulnérabilité élevée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: nvme: skip the zoned limits update if the zone info query failed nvme_query_zone_info() returns either a negative errno or a positive NVMe status code, but nvme_update_ns_info_block() only tests for the negative case: ret = nvme_query_zone_info(ns, lbaf, &zi); if (ret < 0) goto out; If the device fails the Identify Namespace (I/O Command Set specific) command, or the Identify Controller command issued by nvme_set_max_append(), the positive status falls through and setup continues with the zero-initialized zone info. nvme_update_zone_info() then marks the queue zoned with chunk_sectors and ns->head->zsze set to zero. blk_validate_zoned_limits() does not check chunk_sectors, so the limits commit succeeds. blk_revalidate_disk_zones() does reject the zero zone size, but by then the limits are live and nothing rolls them back, so I/O keeps being submitted to a zoned queue with a zero zone size and disk_zone_no() shifts by ilog2(0): nvme0n1: Invalid non power of two zone size (0) UBSAN: shift-out-of-bounds in include/linux/blkdev.h:747:16 shift exponent -1 is negative disk_zone_no include/linux/blkdev.h:747 [inline] bio_straddles_zones include/linux/blkdev.h:1058 [inline] blk_zone_wplug_handle_write block/blk-zoned.c:1423 [inline] blk_zone_plug_bio.cold+0x25/0x1c8 block/blk-zoned.c:1605 blk_mq_submit_bio+0x18fb/0x2870 block/blk-mq.c:3196 submit_bh_wbc+0x575/0x740 fs/buffer.c:2824 __block_write_full_folio+0x728/0xdd0 fs/buffer.c:1933 Any device, firmware or NVMe-oF target that fails this one command reaches this. Skip the zoned limits update in that case, and log which of the two things happened: during a revalidation the queue keeps the zone geometry it was last validated with, and on a first scan the namespace is registered without zoned limits, so that it is still available as a handle for admin commands. Neither of the paths in nvme_query_zone_info() that return a positive status logs anything, so the failure would otherwise be silent. zi.zone_size is an exact indicator: every path that returns a positive status returns before it is assigned, and after that the only failure left is -ENODEV, which the caller already handles. Found by FuzzNvme.
Gravité et risque d'exploitation
CVE-2026-89971 obtient un score CVSS de 7.5/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.60 %, ce qui la place devant 47.8 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions 6.9, 6.18.52, <=*, c85c9ab926a592e2f59f7d9a6ca7d6562843d8fa, <=6.12.*, <3838e80fcfb32e62baffb63c6dc0a60153665a4d, <=7.2.*, 6.12.112, <=6.18.*, <6.9, 0, <7fad53ae2052a2b4fc7ca567d6555bdb1176ba35, 7.2.5, <a75258e651d91ec25424cd94d824d192c11ccc24, <bb6dafa79040357cf5043836e1db108c2af8b1e1, 7.3) 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.