CVE-2026-89971

Summary

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.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/7fad53ae2052a2b4fc7ca567d6555bdb1176ba35
• https://git.kernel.org/stable/c/bb6dafa79040357cf5043836e1db108c2af8b1e1
• https://git.kernel.org/stable/c/3838e80fcfb32e62baffb63c6dc0a60153665a4d

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