null_blk: reject per-device queue resize for shared tag set
In the Linux kernel, the following vulnerability has been resolved: null_blk: reject per-device queue resize for shared tag set When shared_tags is enabled, null_setup_tagset() makes the device use the global tag_set, whose driver_data stays NULL. null_map_queues() therefore falls back to the module-wide g_submit_queues/g_poll_queues instead of any per-device value. Resizing submit_queues or poll_queues via configfs on such a device calls blk_mq_update_nr_hw_queues() on the shared set, shrinking set->nr_hw_queues. __blk_mq_realloc_hw_ctxs() only grows the q->queue_hw_ctx[] allocation, so on shrink it merely exits and NULLs the now-excess hctx slots. null_map_queues(), however, keeps mapping CPUs with the unchanged g_submit_queues/g_poll_queues, so mq_map[] ends up pointing at those NULLed hctx slots. blk_mq_map_swqueue() then dereferences the NULL hctx (hctx->cpumask), crashing the kernel: [ 460.218374] KASAN: null-ptr-deref in range [0x0000000000000098-0x000000000000009f] [ 460.219003] CPU: 24 UID: 0 PID: 1492 Comm: sh Not tainted 7.2.0-rc2+ #67 PREEMPT(full) [ 460.219792] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014 [ 460.220452] RIP: 0010:blk_mq_map_swqueue+0x4db/0x1430 ...... [ 460.228977] Call Trace: [ 460.229175] [ 460.229354] blk_mq_update_nr_hw_queues+0xd49/0x11c0 [ 460.229779] ? __pfx_blk_mq_update_nr_hw_queues+0x10/0x10 [ 460.230200] nullb_update_nr_hw_queues+0x1a9/0x370 [null_blk] [ 460.230694] nullb_device_submit_queues_stor
CVE-2026-90186
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-90186
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "45919fbfe1c487c17ea1d198534339a5e8abeae3",
"lessThan": "9c7bae099ddc92676ad1b7e29dd6c089e5f6196c",
"versionType": "git"
},
{
"status": "affected",
"version": "45919fbfe1c487c17ea1d198534339a5e8abeae3",
"lessThan": "fcd53f3e8b758c79c3f2420d28a2a1dce6fda61a",
"versionType": "git"
},
{
"status": "affected",
"version": "45919fbfe1c487c17ea1d198534339a5e8abeae3",
"lessThan": "f609f7bf9ce8c2fc427705c4a9f623a281239d06",
"versionType": "git"
},
{
"status": "affected",
"version": "45919fbfe1c487c17ea1d198534339a5e8abeae3",
"lessThan": "3e35ad503386a2e8a0e0460530dcbf421c79f6f2",
"versionType": "git"
},
{
"status": "affected",
"version": "45919fbfe1c487c17ea1d198534339a5e8abeae3",
"lessThan": "baff300541a0012907cdde349728739fe16176d7",
"versionType": "git"
},
{
"status": "affected",
"version": "45919fbfe1c487c17ea1d198534339a5e8abeae3",
"lessThan": "1cdfe2fa62b48728a9b436fbbd3dbe4c11593e24",
"versionType": "git"
}
],
"programFiles": [
"drivers/block/null_blk/main.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.5"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.5",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/block/null_blk/main.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-90186
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #36565 · Revision 1
- Added to Heist Feed
- Publisher date