From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-80988: NTB: ntb_transport: Fail TX enqueue when the QP link is down
Date: Fri, 11 Sep 2026 21:41:34 +0200 [thread overview]
Message-ID: <2026091148-CVE-2026-80988-3734@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
NTB: ntb_transport: Fail TX enqueue when the QP link is down
Commit f195a1a6fe41 ("ntb: Drop packets when qp link is down") meant to
make ntb_transport_tx_enqueue() drop packets submitted while the QP link
is down, but it only returns 0 without consuming the packet. Zero means
success by this function's contract, so ntb_netdev reports NETDEV_TX_OK
and forgets the skb: nothing queued it, nothing frees it, and it leaks,
one skb for every transmit racing a link-down.
Return -ENOLINK instead, restoring the contract that a non-zero return
leaves the buffer owned by the caller. With the preceding patch,
ntb_netdev frees the skb on non-retryable enqueue failures and returns
NETDEV_TX_OK, so a packet racing with link-down is dropped without leaking
or entering a busy retry loop.
The Linux kernel CVE team has assigned CVE-2026-80988 to this issue.
Affected and fixed versions
===========================
Issue introduced in 6.6 with commit f195a1a6fe416882984f8bd6c61afc1383171860 and fixed in 6.12.109 with commit 5eca0d899a3be661a7e2caaaa7467a6fa15d756c
Issue introduced in 6.6 with commit f195a1a6fe416882984f8bd6c61afc1383171860 and fixed in 6.18.50 with commit 894e136b432da75c0352c80299807a5c4b04f167
Issue introduced in 6.6 with commit f195a1a6fe416882984f8bd6c61afc1383171860 and fixed in 7.2.4 with commit 89177732fe1653bbfef10cf5d99bf20cf57762c2
Issue introduced in 6.6 with commit f195a1a6fe416882984f8bd6c61afc1383171860 and fixed in 7.3-rc1 with commit 873ce713fef5dde0939220f04f3484ec86a16fba
Issue introduced in 4.14.326 with commit aa6d6ed213b62cbdb09ea32abbfa085dd987a0c9
Issue introduced in 4.19.295 with commit a8986a61ebee0b54c5d648444fbae09bd1c6dcd2
Issue introduced in 5.4.257 with commit 94491412a2afc8a5aea4c5b455aed86d3486f0b1
Issue introduced in 5.10.195 with commit 3cfdc448e8bfa8a7eaa5af87f357330566124b78
Issue introduced in 5.15.132 with commit bfa051f650a7708183bd86901ca4645dcf88c486
Issue introduced in 6.1.53 with commit 4f4af6b8b7a23fa37decaf43b55403e6bfd8e219
Issue introduced in 6.4.16 with commit c2cd5d993f57f819d46fe62387d3cc34d8468e60
Issue introduced in 6.5.3 with commit 449b1978d4e50b14b2a4de3a26d0b074593926a3
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-2026-80988
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/ntb/ntb_transport.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/5eca0d899a3be661a7e2caaaa7467a6fa15d756c
https://git.kernel.org/stable/c/894e136b432da75c0352c80299807a5c4b04f167
https://git.kernel.org/stable/c/89177732fe1653bbfef10cf5d99bf20cf57762c2
https://git.kernel.org/stable/c/873ce713fef5dde0939220f04f3484ec86a16fba
reply other threads:[~2026-09-11 19:49 UTC|newest]
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