{"id":"CVE-2026-43364","summary":"ublk: fix NULL pointer dereference in ublk_ctrl_set_size()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nublk: fix NULL pointer dereference in ublk_ctrl_set_size()\n\nublk_ctrl_set_size() unconditionally dereferences ub-\u003eub_disk via\nset_capacity_and_notify() without checking if it is NULL.\n\nub-\u003eub_disk is NULL before UBLK_CMD_START_DEV completes (it is only\nassigned in ublk_ctrl_start_dev()) and after UBLK_CMD_STOP_DEV runs\n(ublk_detach_disk() sets it to NULL). Since the UBLK_CMD_UPDATE_SIZE\nhandler performs no state validation, a user can trigger a NULL pointer\ndereference by sending UPDATE_SIZE to a device that has been added but\nnot yet started, or one that has been stopped.\n\nFix this by checking ub-\u003eub_disk under ub-\u003emutex before dereferencing\nit, and returning -ENODEV if the disk is not available.","modified":"2026-07-08T08:13:29.540134259Z","published":"2026-05-08T14:21:17.654Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43364.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/25966fc097691e5c925ad080f64a2f19c5fd940a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c28d945bfa92e15147e93b73f95345b9bec979b0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f13fe6794726755a43090cb680c4c58cea6aa5f1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43364.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43364"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"98b995660bff011d8e00af03abd74ac7d1ac1390"},{"fixed":"f13fe6794726755a43090cb680c4c58cea6aa5f1"},{"fixed":"c28d945bfa92e15147e93b73f95345b9bec979b0"},{"fixed":"25966fc097691e5c925ad080f64a2f19c5fd940a"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43364.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.16.0"},{"fixed":"6.18.20"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43364.json"}}],"schema_version":"1.7.5"}