CVE-2026-99156
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: scsi: st: Fix use-after-free race between st_remove() and st_open() st_remove() drops the probe reference on the scsi_tape with kref_put() and only afterwards removes its index from st_index_idr. If that was the last reference, scsi_tape_release() frees the structure while it is still published in the idr. scsi_tape_get(), called from st_open(), looks up the tape in st_index_idr and takes a reference under st_ref_mutex and st_index_lock. remove_cdevs() does not wait for opens that are already past chrdev_open(), so an open that is blocked on st_ref_mutex while st_remove() holds it can take the mutex as soon as st_remove() drops it, find the freed tpnt in the idr and call kref_get() on it: BUG: KASAN: slab-use-after-free in st_open Write of size 4 ... st_open (drivers/scsi/st.c:254 drivers/scsi/st.c:1291) chrdev_open ... Freed by task ...: kfree st_remove (drivers/scsi/st.c:4512) Remove the index from the idr before dropping the reference, all under st_ref_mutex. A concurrent scsi_tape_get() now either runs first and holds a valid reference that keeps the tape alive, or runs afterwards and finds nothing, so st_open() fails with -ENXIO. This restores the ordering st_remove() had before the conversion to st_index_idr, where the tape was unpublished from scsi_tapes[] before the final kref_put().
View original CVE JSON
{
"id": "CVE-2026-99156",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-28T11:17:35.797",
"lastModified": "2026-10-28T11:17:35.797",
"vulnStatus": "Received",
"cveTags": [],
"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()."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/scsi/st.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6c648d95a6af4a79241a916871df17c84c68ea20",
"lessThan": "a1647b653549ff29f0422a63eabf329b842f3822",
"versionType": "git",
"status": "affected"
},
{
"version": "6c648d95a6af4a79241a916871df17c84c68ea20",
"lessThan": "18a0e3733ce38718688e813e5e2d1106bd4830e5",
"versionType": "git",
"status": "affected"
},
{
"version": "6c648d95a6af4a79241a916871df17c84c68ea20",
"lessThan": "71caf7f84bd62a4bf91cc95abd2de690afb8d15f",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"drivers/scsi/st.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "3.7",
"status": "affected"
},
{
"version": "0",
"lessThan": "3.7",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.59",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.13",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/18a0e3733ce38718688e813e5e2d1106bd4830e5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/71caf7f84bd62a4bf91cc95abd2de690afb8d15f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a1647b653549ff29f0422a63eabf329b842f3822",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}