Description
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: mrp: fix uninitialised bytes on the wire
br_mrp_alloc_test_skb() builds MRP test frames on an skb from
dev_alloc_skb(), which does not clear the linear data area. On the MRA
ring-role branch the sub-option TLV header is appended with
sub_tlv = skb_put(skb, sizeof(*sub_tlv));
sub_tlv->type = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR;
so sub_tlv->length is never written, and the two trailing alignment bytes
are appended with a bare skb_put() that does not clear them either. The
neighbouring oui and sub_opt regions are explicitly zeroed, so three
uninitialised bytes are left in every MRA MRP_Test frame that goes out.
Put the sub-option TLV header and the alignment padding in a single
skb_put_zero(), which clears both. The AUTO_MGR sub-TLV carries no
payload, so the zeroed length field is already the value it should have.
net: bridge: mrp: fix uninitialised bytes on the wire
br_mrp_alloc_test_skb() builds MRP test frames on an skb from
dev_alloc_skb(), which does not clear the linear data area. On the MRA
ring-role branch the sub-option TLV header is appended with
sub_tlv = skb_put(skb, sizeof(*sub_tlv));
sub_tlv->type = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR;
so sub_tlv->length is never written, and the two trailing alignment bytes
are appended with a bare skb_put() that does not clear them either. The
neighbouring oui and sub_opt regions are explicitly zeroed, so three
uninitialised bytes are left in every MRA MRP_Test frame that goes out.
Put the sub-option TLV header and the alignment padding in a single
skb_put_zero(), which clears both. The AUTO_MGR sub-TLV carries no
payload, so the zeroed length field is already the value it should have.
Published:
2026-08-22
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
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 |
|
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| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Sat, 22 Aug 2026 15:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: net: bridge: mrp: fix uninitialised bytes on the wire br_mrp_alloc_test_skb() builds MRP test frames on an skb from dev_alloc_skb(), which does not clear the linear data area. On the MRA ring-role branch the sub-option TLV header is appended with sub_tlv = skb_put(skb, sizeof(*sub_tlv)); sub_tlv->type = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR; so sub_tlv->length is never written, and the two trailing alignment bytes are appended with a bare skb_put() that does not clear them either. The neighbouring oui and sub_opt regions are explicitly zeroed, so three uninitialised bytes are left in every MRA MRP_Test frame that goes out. Put the sub-option TLV header and the alignment padding in a single skb_put_zero(), which clears both. The AUTO_MGR sub-TLV carries no payload, so the zeroed length field is already the value it should have. | |
| Title | net: bridge: mrp: fix uninitialised bytes on the wire | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-22T15:32:32.926Z
Reserved: 2026-08-15T05:44:03.924Z
Link: CVE-2026-74659
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-08-22T16:16:39.613
Modified: 2026-08-22T16:16:39.613
Link: CVE-2026-74659
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.