{"id":"CVE-2026-43364","state":"PUBLISHED","title":"ublk: fix NULL pointer dereference in ublk_ctrl_set_size()","description":"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->ub_disk via\nset_capacity_and_notify() without checking if it is NULL.\n\nub->ub_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->ub_disk under ub->mutex before dereferencing\nit, and returning -ENODEV if the disk is not available.","publishedAt":"2026-05-08T14:21:17.654Z","updatedAt":"2026-05-11T22:23:09.555Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"98b995660bff011d8e00af03abd74ac7d1ac1390","status":"affected","lessThan":"f13fe6794726755a43090cb680c4c58cea6aa5f1","versionType":"git"},{"version":"98b995660bff011d8e00af03abd74ac7d1ac1390","status":"affected","lessThan":"c28d945bfa92e15147e93b73f95345b9bec979b0","versionType":"git"},{"version":"98b995660bff011d8e00af03abd74ac7d1ac1390","status":"affected","lessThan":"25966fc097691e5c925ad080f64a2f19c5fd940a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/ublk_drv.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.20","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/ublk_drv.c"]}],"references":["https://git.kernel.org/stable/c/f13fe6794726755a43090cb680c4c58cea6aa5f1","https://git.kernel.org/stable/c/c28d945bfa92e15147e93b73f95345b9bec979b0","https://git.kernel.org/stable/c/25966fc097691e5c925ad080f64a2f19c5fd940a"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43364.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43364","state":"PUBLISHED","datePublished":"2026-05-08T14:21:17.654Z","dateUpdated":"2026-05-11T22:23:09.555Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:56.005Z"},"containers":{"cna":{"title":"ublk: fix NULL pointer dereference in ublk_ctrl_set_size()","descriptions":[{"lang":"en","value":"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->ub_disk via\nset_capacity_and_notify() without checking if it is NULL.\n\nub->ub_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->ub_disk under ub->mutex before dereferencing\nit, and returning -ENODEV if the disk is not available."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"98b995660bff011d8e00af03abd74ac7d1ac1390","status":"affected","lessThan":"f13fe6794726755a43090cb680c4c58cea6aa5f1","versionType":"git"},{"version":"98b995660bff011d8e00af03abd74ac7d1ac1390","status":"affected","lessThan":"c28d945bfa92e15147e93b73f95345b9bec979b0","versionType":"git"},{"version":"98b995660bff011d8e00af03abd74ac7d1ac1390","status":"affected","lessThan":"25966fc097691e5c925ad080f64a2f19c5fd940a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/ublk_drv.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.20","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/ublk_drv.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f13fe6794726755a43090cb680c4c58cea6aa5f1"},{"url":"https://git.kernel.org/stable/c/c28d945bfa92e15147e93b73f95345b9bec979b0"},{"url":"https://git.kernel.org/stable/c/25966fc097691e5c925ad080f64a2f19c5fd940a"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T22:23:09.555Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.20"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.19.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}