CVE-2026-74622: net: atlantic: free RX pages of consumed but not refilled buffers

From: Greg Kroah-Hartman <[email protected]>

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

In the Linux kernel, the following vulnerability has been resolved:

net: atlantic: free RX pages of consumed but not refilled buffers

aq_ring_rx_deinit() only walks [sw_head, sw_tail), the region posted to
hardware. Since the page reuse strategy was added, a cleaned RX buffer
keeps its page (and its DMA mapping) in the ring for reuse, and refill
is batched: aq_ring_rx_fill() returns early until AQ_CFG_RX_REFILL_THRES
slots are free. Slots that were consumed but not yet reposted therefore
sit in the complementary [sw_tail, sw_head) gap with a live page, and
the deinit walk never visits them: up to a refill batch worth of pages
and DMA mappings leak on every interface down.

Walk the whole ring instead and release whatever is still there. Also
bail out if the buffer ring is already gone: a partial
aq_ptp_ring_alloc() failure frees the ring but leaves aq_nic set, so
aq_ptp_ring_deinit() still gets here on the unwind path.

The Linux kernel CVE team has assigned CVE-2026-74622 to this issue.


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

	Issue introduced in 5.2 with commit 46f4c29d9de6e4a9d4ed7de9a37dd42501d89f86 and fixed in 5.10.265 with commit 1e58b0bab40dcbdfc04acaba6a221d40801c3770
	Issue introduced in 5.2 with commit 46f4c29d9de6e4a9d4ed7de9a37dd42501d89f86 and fixed in 5.15.216 with commit 30c473ea097ef0c93b064281b3e295c97d17e28b
	Issue introduced in 5.2 with commit 46f4c29d9de6e4a9d4ed7de9a37dd42501d89f86 and fixed in 6.1.183 with commit 17c99dd86f169c7a3e73d6778e79ef5b1ed3ceac
	Issue introduced in 5.2 with commit 46f4c29d9de6e4a9d4ed7de9a37dd42501d89f86 and fixed in 6.6.152 with commit ff451bc4290b79c04f1c5cfa928d448f9d47ecf5
	Issue introduced in 5.2 with commit 46f4c29d9de6e4a9d4ed7de9a37dd42501d89f86 and fixed in 6.12.104 with commit 64e1346bc66b947eb80b848e4c8d9828ba50e0fe
	Issue introduced in 5.2 with commit 46f4c29d9de6e4a9d4ed7de9a37dd42501d89f86 and fixed in 6.18.45 with commit 782cc40b7ade4614a8aec0b948b8cf95c69f8d4b
	Issue introduced in 5.2 with commit 46f4c29d9de6e4a9d4ed7de9a37dd42501d89f86 and fixed in 7.1.9 with commit 24d87dc28ddd3771dd0e88719209811809729439
	Issue introduced in 5.2 with commit 46f4c29d9de6e4a9d4ed7de9a37dd42501d89f86 and fixed in 7.2 with commit e8e7471ef686b6c002218fee9671cc61992ae01a

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-2026-74622
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:
	drivers/net/ethernet/aquantia/atlantic/aq_ring.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/1e58b0bab40dcbdfc04acaba6a221d40801c3770
	https://git.kernel.org/stable/c/30c473ea097ef0c93b064281b3e295c97d17e28b
	https://git.kernel.org/stable/c/17c99dd86f169c7a3e73d6778e79ef5b1ed3ceac
	https://git.kernel.org/stable/c/ff451bc4290b79c04f1c5cfa928d448f9d47ecf5
	https://git.kernel.org/stable/c/64e1346bc66b947eb80b848e4c8d9828ba50e0fe
	https://git.kernel.org/stable/c/782cc40b7ade4614a8aec0b948b8cf95c69f8d4b
	https://git.kernel.org/stable/c/24d87dc28ddd3771dd0e88719209811809729439
	https://git.kernel.org/stable/c/e8e7471ef686b6c002218fee9671cc61992ae01a