netfilter: handle unreadable frags
sashiko reports:
When an skb with unreadable fragments (such as from devmem TCP, where
skb_frags_readable(skb) returns false) is processed by the u32 module,
skb_copy_bits() will safely return a negative error code [..]
xt_u32: bail out with hotdrop in this case.
gather_frags: return -1, just as if we had no fragment header.
nfnetlink_queue: restrict to the linear part.
nfnetlink_log: restrict to the linear part.
v2:
- skb_zerocopy helpers don't copy readable flag, i.e. nfnetlink_queue
is broken too
xt_u32 shouldn't return true if hotdrop was set.
Analysis
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Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
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| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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No vendor fix or workaround currently provided.
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Tracking
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Sat, 25 Jul 2026 09:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: netfilter: handle unreadable frags sashiko reports: When an skb with unreadable fragments (such as from devmem TCP, where skb_frags_readable(skb) returns false) is processed by the u32 module, skb_copy_bits() will safely return a negative error code [..] xt_u32: bail out with hotdrop in this case. gather_frags: return -1, just as if we had no fragment header. nfnetlink_queue: restrict to the linear part. nfnetlink_log: restrict to the linear part. v2: - skb_zerocopy helpers don't copy readable flag, i.e. nfnetlink_queue is broken too xt_u32 shouldn't return true if hotdrop was set. | |
| Title | netfilter: handle unreadable frags | |
| 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: 2026-07-25T08:50:54.495Z
Reserved: 2026-07-19T15:36:31.786Z
Link: CVE-2026-64414
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
No data.
No weakness.