GHSA-X7FX-9652-J55V
Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-13 09:32In the Linux kernel, the following vulnerability has been resolved:
cxl/features: bound fwctl command payload to the input buffer
fwctl_cmd_rpc() copies cmd->in_len bytes into inbuf = kvzalloc(cmd->in_len) and passes inbuf and in_len to ->fw_rpc(). The CXL callback cxlctl_fw_rpc() ignores in_len and never checks the user-controlled op_size against it.
cxlctl_set_feature() bounds op_size only from below (op_size <= sizeof(feat_in->hdr)) and then reads op_size - sizeof(hdr) bytes from feat_in->feat_data via cxl_set_feature(). With a small in_len and a large op_size the first memcpy() already reads past the kvzalloc(in_len) buffer; the out-of-bounds bytes are placed in the mailbox payload and sent to the device, and a large enough op_size can walk into unmapped memory and oops the kernel. The Get paths pin op_size to a fixed size but likewise read the input struct without checking in_len.
Reject, at the single dispatch point, any request whose fixed header plus op_size does not fit in the copied-in buffer. The lower-bound test guards the subtraction and ensures op_size was copied in before it is read.
{
"affected": [],
"aliases": [
"CVE-2026-89571"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-11T20:19:41Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/features: bound fwctl command payload to the input buffer\n\nfwctl_cmd_rpc() copies cmd-\u003ein_len bytes into inbuf = kvzalloc(cmd-\u003ein_len)\nand passes inbuf and in_len to -\u003efw_rpc(). The CXL callback cxlctl_fw_rpc()\nignores in_len and never checks the user-controlled op_size against it.\n\ncxlctl_set_feature() bounds op_size only from below\n(op_size \u003c= sizeof(feat_in-\u003ehdr)) and then reads op_size - sizeof(hdr)\nbytes from feat_in-\u003efeat_data via cxl_set_feature(). With a small in_len\nand a large op_size the first memcpy() already reads past the\nkvzalloc(in_len) buffer; the out-of-bounds bytes are placed in the mailbox\npayload and sent to the device, and a large enough op_size can walk into\nunmapped memory and oops the kernel. The Get paths pin op_size to a fixed\nsize but likewise read the input struct without checking in_len.\n\nReject, at the single dispatch point, any request whose fixed header plus\nop_size does not fit in the copied-in buffer. The lower-bound test guards\nthe subtraction and ensures op_size was copied in before it is read.",
"id": "GHSA-x7fx-9652-j55v",
"modified": "2026-09-13T09:32:19Z",
"published": "2026-09-11T21:31:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89571"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/14d52c15d5d99477b20a2d61fe36f347080da6cd"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d8957545fe96f7905791c937758ebfc1ae1e5b17"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f687394af983df5660b6afae7e0d06969f3af206"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"type": "CVSS_V3"
}
]
}
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