{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99156","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-25T10:25:14.397Z","datePublished":"2026-10-28T10:35:10.493Z","dateUpdated":"2026-10-31T12:44:14.895Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-31T12:44:14.895Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: st: Fix use-after-free race between st_remove() and st_open()\n\nst_remove() drops the probe reference on the scsi_tape with kref_put()\nand only afterwards removes its index from st_index_idr. If that was the\nlast reference, scsi_tape_release() frees the structure while it is\nstill published in the idr.\n\nscsi_tape_get(), called from st_open(), looks up the tape in\nst_index_idr and takes a reference under st_ref_mutex and\nst_index_lock. remove_cdevs() does not wait for opens that are already\npast chrdev_open(), so an open that is blocked on st_ref_mutex while\nst_remove() holds it can take the mutex as soon as st_remove() drops it,\nfind the freed tpnt in the idr and call kref_get() on it:\n\n  BUG: KASAN: slab-use-after-free in st_open\n  Write of size 4 ...\n   st_open (drivers/scsi/st.c:254 drivers/scsi/st.c:1291)\n   chrdev_open\n  ...\n  Freed by task ...:\n   kfree\n   st_remove (drivers/scsi/st.c:4512)\n\nRemove the index from the idr before dropping the reference, all under\nst_ref_mutex. A concurrent scsi_tape_get() now either runs first and\nholds a valid reference that keeps the tape alive, or runs afterwards\nand finds nothing, so st_open() fails with -ENXIO.\n\nThis restores the ordering st_remove() had before the conversion to\nst_index_idr, where the tape was unpublished from scsi_tapes[] before\nthe final kref_put()."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - A local openat() reaches st_open() through chrdev_open(), then scsi_tape_get(); concurrent hot-unplug reaches the patched st_remove() through __scsi_remove_device(), with no network-supplied input.\nAC:L - A tape-device user controlling a hotpluggable TYPE_TAPE device can flood /dev/stN opens while disconnecting it, controlling both st_open() and st_remove() and retrying the race at will.\nPR:L - st_open() and scsi_tape_get() perform no capability check; may_open() applies device-node DAC and device-cgroup policy, so a tape-group user controlling an external tape needs no init-namespace administrative privilege.\nUI:N - The attacker performs both the /dev/stN open flood and device disconnect; no separate victim must open the tape, remove it, or mount attacker-supplied content.\nS:U - The freed scsi_tape object and subsequent corruption remain within the host kernel's SCSI-tape authority, without crossing a VM, IOMMU, or sandbox security boundary.\nC:H - st_remove() leaves a freed kmalloc-1k scsi_tape in st_index_idr; scsi_tape_get() reads its device pointer and st_open() follows buffer and mode pointers from reclaimable storage, enabling kernel-memory disclosure.\nI:H - kref_get() performs a confirmed four-byte write into the freed scsi_tape, and successful reclamation exposes further st_open() writes through in_use, state, and buffer fields, supporting control-flow hijacking.\nA:H - The stale device and buffer pointers are subsequently dereferenced by scsi_device_get() and st_open() buffer handling; the reported UAF proceeds to unrelated corruption, oops/GPF, and kernel panic."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/scsi/st.c"],"versions":[{"version":"6c648d95a6af4a79241a916871df17c84c68ea20","lessThan":"7d7f9d2ee4b0841f3eba9fa3627044ad329428de","status":"affected","versionType":"git"},{"version":"6c648d95a6af4a79241a916871df17c84c68ea20","lessThan":"d9517fc39ec3ee13eadefdc17f45300f7d23ed8c","status":"affected","versionType":"git"},{"version":"6c648d95a6af4a79241a916871df17c84c68ea20","lessThan":"e7a5da4a4820210aa7d7cd8e6eb25aabe9e5b5a7","status":"affected","versionType":"git"},{"version":"6c648d95a6af4a79241a916871df17c84c68ea20","lessThan":"00ff1128123d4bdfacd28d68fb4b6e6f657a3648","status":"affected","versionType":"git"},{"version":"6c648d95a6af4a79241a916871df17c84c68ea20","lessThan":"5ef230f734e0d23db007c8405f38b7e226740084","status":"affected","versionType":"git"},{"version":"6c648d95a6af4a79241a916871df17c84c68ea20","lessThan":"a1647b653549ff29f0422a63eabf329b842f3822","status":"affected","versionType":"git"},{"version":"6c648d95a6af4a79241a916871df17c84c68ea20","lessThan":"18a0e3733ce38718688e813e5e2d1106bd4830e5","status":"affected","versionType":"git"},{"version":"6c648d95a6af4a79241a916871df17c84c68ea20","lessThan":"71caf7f84bd62a4bf91cc95abd2de690afb8d15f","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/scsi/st.c"],"versions":[{"version":"3.7","status":"affected"},{"version":"0","lessThan":"3.7","status":"unaffected","versionType":"semver"},{"version":"5.10.273","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.224","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.191","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.161","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.115","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.59","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.13","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"6.6.161"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"6.12.115"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"6.18.59"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"7.2.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"7.3"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/7d7f9d2ee4b0841f3eba9fa3627044ad329428de"},{"url":"https://git.kernel.org/stable/c/d9517fc39ec3ee13eadefdc17f45300f7d23ed8c"},{"url":"https://git.kernel.org/stable/c/e7a5da4a4820210aa7d7cd8e6eb25aabe9e5b5a7"},{"url":"https://git.kernel.org/stable/c/00ff1128123d4bdfacd28d68fb4b6e6f657a3648"},{"url":"https://git.kernel.org/stable/c/5ef230f734e0d23db007c8405f38b7e226740084"},{"url":"https://git.kernel.org/stable/c/a1647b653549ff29f0422a63eabf329b842f3822"},{"url":"https://git.kernel.org/stable/c/18a0e3733ce38718688e813e5e2d1106bd4830e5"},{"url":"https://git.kernel.org/stable/c/71caf7f84bd62a4bf91cc95abd2de690afb8d15f"}],"title":"scsi: st: Fix use-after-free race between st_remove() and st_open()","x_generator":{"engine":"bippy-1.2.0"}}}}