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.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
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No data.
No advisories yet.
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Sat, 12 Sep 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-125 | |
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Fri, 11 Sep 2026 23:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In 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. | |
| Title | cxl/features: bound fwctl command payload to the input buffer | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-11T19:44:40.328Z
Reserved: 2026-09-11T19:38:34.726Z
Link: CVE-2026-89571
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-11T20:19:41.160
Modified: 2026-09-11T20:19:41.160
Link: CVE-2026-89571
Redhat
OpenCVE Enrichment
Updated: 2026-09-12T04:15:05Z