GHSA-F335-4FHR-WM5C
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-23 15:32In the Linux kernel, the following vulnerability has been resolved:
scsi: target: Bound PR-OUT TransportID parsing to the received buffer
core_scsi3_decode_spec_i_port() and core_scsi3_emulate_register_and_move() hand the raw PERSISTENT RESERVE OUT parameter buffer to target_parse_pr_out_transport_id() without telling it how many bytes are valid. For an iSCSI TransportID (FORMAT CODE 01b), iscsi_parse_pr_out_transport_id() locates the ",i,0x" ISID separator with an unbounded strstr() (and on the error path prints the name with a further unbounded "%s"). An initiator can submit a TransportID whose iSCSI name contains neither a ",i,0x" substring nor a NUL terminator, filling the parameter list to its end, so the scan runs off the end of the buffer.
When the parameter list spans more than one page the buffer is a multi-page vmap (transport_kmap_data_sg()), so the over-read walks into the trailing vmalloc guard page and oopses (KASAN: vmalloc-out-of-bounds in strstr). It is reachable by any fabric that delivers a PR OUT to a device exported through an iSCSI TPG, including a guest via vhost-scsi.
Pass the number of received bytes down to the parser and validate the iSCSI TransportID's own self-described length (ADDITIONAL LENGTH + 4) once, up front: reject it if it is below the spc4r17 minimum or larger than the received buffer, then bound the separator search, the ISID walk and the name copy by that length. This is the length check the callers already perform after the parse (core_scsi3_decode_spec_i_port() compares tid_len against tpdl, core_scsi3_emulate_register_and_move() validates it against data_length), moved ahead of the scan. Also drop the unbounded "%s" of the unterminated name.
Add per-format explicit name-length checks before copying into i_str, rather than silently truncating with min_t: for FORMAT CODE 00b reject if the descriptor body (tid_len - 4 bytes) cannot fit in i_str[TRANSPORT_IQN_LEN]; for FORMAT CODE 01b reject if the name portion (from &buf[4] up to the separator) cannot fit. Both checks make the bounds intent explicit at each format branch.
While here, also reject a FORMAT CODE 01b TransportID whose ",i,0x" separator sits at the very end of the descriptor: that leaves an empty ISID and points the returned port nexus pointer at buf + tid_len, one past the descriptor, which the registration code (__core_scsi3_locate_pr_reg(), __core_scsi3_alloc_registration()) then dereferences as the ISID string -- the same over-read of the parameter buffer for a malformed descriptor.
{
"affected": [],
"aliases": [
"CVE-2026-72084"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:21:22Z",
"severity": "CRITICAL"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: target: Bound PR-OUT TransportID parsing to the received buffer\n\ncore_scsi3_decode_spec_i_port() and core_scsi3_emulate_register_and_move()\nhand the raw PERSISTENT RESERVE OUT parameter buffer to\ntarget_parse_pr_out_transport_id() without telling it how many bytes are\nvalid. For an iSCSI TransportID (FORMAT CODE 01b),\niscsi_parse_pr_out_transport_id() locates the \",i,0x\" ISID separator with\nan unbounded strstr() (and on the error path prints the name with a further\nunbounded \"%s\"). An initiator can submit a TransportID whose iSCSI name\ncontains neither a \",i,0x\" substring nor a NUL terminator, filling the\nparameter list to its end, so the scan runs off the end of the buffer.\n\nWhen the parameter list spans more than one page the buffer is a multi-page\nvmap (transport_kmap_data_sg()), so the over-read walks into the trailing\nvmalloc guard page and oopses (KASAN: vmalloc-out-of-bounds in strstr). It\nis reachable by any fabric that delivers a PR OUT to a device exported\nthrough an iSCSI TPG, including a guest via vhost-scsi.\n\nPass the number of received bytes down to the parser and validate the iSCSI\nTransportID\u0027s own self-described length (ADDITIONAL LENGTH + 4) once, up\nfront: reject it if it is below the spc4r17 minimum or larger than the\nreceived buffer, then bound the separator search, the ISID walk and the\nname copy by that length. This is the length check the callers already\nperform after the parse (core_scsi3_decode_spec_i_port() compares tid_len\nagainst tpdl, core_scsi3_emulate_register_and_move() validates it against\ndata_length), moved ahead of the scan. Also drop the unbounded \"%s\" of the\nunterminated name.\n\nAdd per-format explicit name-length checks before copying into i_str,\nrather than silently truncating with min_t: for FORMAT CODE 00b reject if\nthe descriptor body (tid_len - 4 bytes) cannot fit in\ni_str[TRANSPORT_IQN_LEN]; for FORMAT CODE 01b reject if the name portion\n(from \u0026buf[4] up to the separator) cannot fit. Both checks make the bounds\nintent explicit at each format branch.\n\nWhile here, also reject a FORMAT CODE 01b TransportID whose \",i,0x\"\nseparator sits at the very end of the descriptor: that leaves an empty ISID\nand points the returned port nexus pointer at buf + tid_len, one past the\ndescriptor, which the registration code (__core_scsi3_locate_pr_reg(),\n__core_scsi3_alloc_registration()) then dereferences as the ISID string --\nthe same over-read of the parameter buffer for a malformed descriptor.",
"id": "GHSA-f335-4fhr-wm5c",
"modified": "2026-08-23T15:32:59Z",
"published": "2026-08-15T06:32:11Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72084"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/004ccd2d3b4ac36a300e05e01df152e5c02a5a82"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/03fbc7de8d5e85fc8420e57e8304c855efd453ab"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/555a89846ed888d7401b3f7200934c0fbedcbb46"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6ca5de8782e67573a61a6736b6dc0ffe58dcdf59"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/842248047ef28dbf3b3f7f49a0ec315054d4dab8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/88c67c3de914e19172e1d878a7625c5b06c20ec5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9298078a8f7d8181a04614a34ab655ccdf038204"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d04a179085c262c9ed577d0a4cbc6482ff1fd9a3"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.