Bug 2507031 (CVE-2026-64355) - CVE-2026-64355 kernel: bpf: Reject fragmented frames in devmap
Summary: CVE-2026-64355 kernel: bpf: Reject fragmented frames in devmap
Keywords:
Status: NEW
Alias: CVE-2026-64355
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-25 10:01 UTC by OSIDB Bzimport
Modified: 2026-09-07 10:10 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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Description OSIDB Bzimport 2026-07-25 10:01:26 UTC
In the Linux kernel, the following vulnerability has been resolved:

bpf: Reject fragmented frames in devmap

Devmap broadcast redirects clone the packet for all but the last
destination.

For native XDP, that clone path copies only the linear xdp_frame data,
while fragmented frames keep skb_shared_info in tailroom outside the
linear area. Cloning such a frame leaves XDP_FLAGS_HAS_FRAGS set but
without valid frag metadata, and the later free path can interpret
uninitialized tail data as skb_shared_info, leading to an out-of-bounds
access during frame return.

Reject fragmented native XDP frames in dev_map_enqueue_clone().

Add the same restriction to the generic XDP clone path in
dev_map_redirect_clone(). Generic XDP represents fragmented packets as
nonlinear skbs, and rejecting them here keeps clone-based broadcast
support aligned between native and generic XDP.

Comment 1 Mauro Matteo Cascella 2026-07-28 15:40:00 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072519-CVE-2026-64355-35d5@gregkh/T


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