CVE-2026-64355: bpf: Reject fragmented frames in devmap

CVE-2026-64355: bpf: Reject fragmented frames in devmap

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

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.

The Linux kernel CVE team has assigned CVE-2026-64355 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.14 with commit e624d4ed4aa8cc3c69d1359b0aaea539203ed266 and fixed in 5.15.212 with commit 47baddc856ae7e93a565dd9deeb797999b179466
	Issue introduced in 5.14 with commit e624d4ed4aa8cc3c69d1359b0aaea539203ed266 and fixed in 6.1.178 with commit 07a4c11ee8ef4abcb39d922e9e410ae269671cdf
	Issue introduced in 5.14 with commit e624d4ed4aa8cc3c69d1359b0aaea539203ed266 and fixed in 6.6.145 with commit bccbab36ff228e0825eb85d9b0f9b8434cd0a399
	Issue introduced in 5.14 with commit e624d4ed4aa8cc3c69d1359b0aaea539203ed266 and fixed in 6.12.96 with commit c5b4f5efcb55c1af3fe44ff712d31b7fb098a831
	Issue introduced in 5.14 with commit e624d4ed4aa8cc3c69d1359b0aaea539203ed266 and fixed in 6.18.39 with commit a9bb2d9c798cb62a4050a991c27b752770c33afe
	Issue introduced in 5.14 with commit e624d4ed4aa8cc3c69d1359b0aaea539203ed266 and fixed in 7.1.4 with commit 51d07c12ca411e692c424ecdabf077f1e61a61be
	Issue introduced in 5.14 with commit e624d4ed4aa8cc3c69d1359b0aaea539203ed266 and fixed in 7.2-rc1 with commit aa496720618f1a6054f1c870bf10b4f6c99bf656

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-64355
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	kernel/bpf/devmap.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/47baddc856ae7e93a565dd9deeb797999b179466
	https://git.kernel.org/stable/c/07a4c11ee8ef4abcb39d922e9e410ae269671cdf
	https://git.kernel.org/stable/c/bccbab36ff228e0825eb85d9b0f9b8434cd0a399
	https://git.kernel.org/stable/c/c5b4f5efcb55c1af3fe44ff712d31b7fb098a831
	https://git.kernel.org/stable/c/a9bb2d9c798cb62a4050a991c27b752770c33afe
	https://git.kernel.org/stable/c/51d07c12ca411e692c424ecdabf077f1e61a61be
	https://git.kernel.org/stable/c/aa496720618f1a6054f1c870bf10b4f6c99bf656