In the Linux kernel, the following vulnerability has been resolved:
ethtool: cmis: require exact CDB reply length
Malicious SFP module could respond with rpl_len longer than
what cmis_cdb_process_reply() expected, leading to OOB writes.
Malicious HW is a bit theoretical but some modules may just
be buggy and/or the reads may occasionally get corrupted,
so let's protect the kernel.
The existing check protects from short replies. We need to
protect from long ones, too. All callers that pass a non-zero
rpl_exp_len cast the reply payload to a fixed-layout struct
and read fields at fixed offsets, with no version negotiation
or short-reply handling:
- cmis_cdb_validate_password()
- cmis_cdb_module_features_get()
- cmis_fw_update_fw_mng_features_get()
so let's assume that responses longer than expected do not
have to be handled gracefully here. Add a warning message
to make the debug easier in case my understanding is wrong...
Note that page_data->length (argument of kmalloc) comes from
last arg to ethtool_cmis_page_init() which is rpl_exp_len.
Note2 that AIs also like to point out overflows in args->req.payload
itself (which is a fixed-size 120 B buffer, on the stack),
but callers should be reading structs defined by the standard,
so protecting from requests for more data than max seem like
defensive programming.
References
Configurations
Configuration 1 (hide)
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History
02 Oct 2026, 19:58
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* |
|
| First Time |
Linux
Linux linux Kernel |
|
| CWE | CWE-787 | |
| References | () https://git.kernel.org/stable/c/2f818cc98fd2c63a08239cb48995f6c3bfe9d9b3 - Patch | |
| References | () https://git.kernel.org/stable/c/4d42fb88ec61f2e98c33a9e3a2de371d5edbc6b1 - Patch | |
| References | () https://git.kernel.org/stable/c/6c3f999a9d1338c6c89a9ff4549eafe72bc2e7b1 - Patch | |
| References | () https://git.kernel.org/stable/c/eb5dcd740cd7fa27bc2caeff2d28ef28e93ff4d3 - Patch |
Information
Published : 2026-07-19 16:17
Updated : 2026-10-19 21:17
NVD link : CVE-2026-63996
Mitre link : CVE-2026-63996
CVE.ORG link : CVE-2026-63996
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-787
Out-of-bounds Write
