CVE-2026-43364ublk: fix NULL pointer dereference in ublk_ctrl_set_size()
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: ublk: fix NULL pointer dereference in ublk_ctrl_set_size() ublk_ctrl_set_size() unconditionally dereferences ub->ub_disk via set_capacity_and_notify() without checking if it is NULL. ub->ub_disk is NULL before UBLK_CMD_START_DEV completes (it is only assigned in ublk_ctrl_start_dev()) and after UBLK_CMD_STOP_DEV runs (ublk_detach_disk() sets it to NULL). Since the UBLK_CMD_UPDATE_SIZE handler performs no state validation, a user can trigger a NULL pointer dereference by sending UPDATE_SIZE to a device that has been added but not yet started, or one that has been stopped. Fix this by checking ub->ub_disk under ub->mutex before dereferencing it, and returning -ENODEV if the disk is not available.
- CVSS
- 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- May 11, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 98b995660bff011d8e00af03abd74ac7d1ac1390 before f13fe6794726755a43090cb680c4c58cea6aa5f1; from 98b995660bff011d8e00af03abd74ac7d1ac1390 before c28d945bfa92e15147e93b73f95345b9bec979b0; from 98b995660bff011d8e00af03abd74ac7d1ac1390 before 25966fc097691e5c925ad080f64a2f19c5fd940a | CNA record |
linux linux_kernel linux:linux_kernel | from 6.16 before 6.18.20; from 6.19 before 6.19.9; 7.0; 7.0; 7.0 | NVD |
References
- https://git.kernel.org/stable/c/f13fe6794726755a43090cb680c4c58cea6aa5f1patch
- https://git.kernel.org/stable/c/c28d945bfa92e15147e93b73f95345b9bec979b0patch
- https://git.kernel.org/stable/c/25966fc097691e5c925ad080f64a2f19c5fd940apatch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.