CVE-2026-23148

CVE-2026-23148 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: nvmet: fix race in nvmet_bio_done() leading to NULL pointer dereference There is a race condition in nvmet_bio_done() that can cause a NULL pointer dereference in blk_cgroup_bio_start(): 1. nvmet_bio_done() is called when a bio completes 2. nvmet_req_complete() is called, which invokes req->ops->queue_response(req) 3. The queue_response callback can re-queue and re-submit the same request 4. The re-submission reuses the same inline_bio from nvmet_req 5. Meanwhile, nvmet_req_bio_put() (called after nvmet_req_complete) invokes bio_uninit() for inline_bio, which sets bio->bi_blkg to NULL 6. The re-submitted bio enters submit_bio_noacct_nocheck() 7. blk_cgroup_bio_start() dereferences bio->bi_blkg, causing a crash: BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode RIP: 0010:blk_cgroup_bio_start+0x10/0xd0 Call Trace: submit_bio_noacct_nocheck+0x44/0x250 nvmet_bdev_execute_rw+0x254/0x370 [nvmet] process_one_work+0x193/0x3c0 worker_thread+0x281/0x3a0 Fix this by reordering nvmet_bio_done() to call nvmet_req_bio_put() BEFORE nvmet_req_complete(). This ensures the bio is cleaned up before the request can be re-submitted, preventing the race condition.

Frequently asked questions

What is CVE-2026-23148?
In the Linux kernel, the following vulnerability has been resolved: nvmet: fix race in nvmet_bio_done() leading to NULL pointer dereference There is a race condition in nvmet_bio_done() that can cause a NULL pointer dereference in blk_cgroup_bio_start(): 1. nvmet_bio_done() is called when a bio completes 2. nvmet_req_complete() is called, which invokes req->ops->queue_response(req) 3. The queue_response callback can re-queue and re-submit the same request 4. The re-submission reuses the same inline_bio from nvmet_req 5. Meanwhile, nvmet_req_bio_put() (called after nvmet_req_complete) invokes bio_uninit() for inline_bio, which sets bio->bi_blkg to NULL 6. The re-submitted bio enters submit_bio_noacct_nocheck() 7. blk_cgroup_bio_start() dereferences bio->bi_blkg, causing a crash: BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode RIP: 0010:blk_cgroup_bio_start+0x10/0xd0 Call Trace: submit_bio_noacct_nocheck+0x44/0x250 nvmet_bdev_execute_rw+0x254/0x370 [nvmet] process_one_work+0x193/0x3c0 worker_thread+0x281/0x3a0 Fix this by reordering nvmet_bio_done() to call nvmet_req_bio_put() BEFORE nvmet_req_complete(). This ensures the bio is cleaned up before the request can be re-submitted, preventing the race condition.
How severe is CVE-2026-23148?
CVE-2026-23148 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-23148 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-23148?
CVE-2026-23148 primarily affects Linux Linux Kernel. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-23148?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-23148 have an EU (EUVD) identifier?
Yes. CVE-2026-23148 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5887.
When was CVE-2026-23148 published?
CVE-2026-23148 was published on 2026-02-14 and last updated on 2026-06-17.

References

Affected products (12)

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