{ "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with -ENXIO.\n\nThis restores the ordering st_remove() had before the conversion to\nst_index_idr, where the tape was unpublished from scsi_tapes[] before\nthe final kref_put()."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" } } } }