From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-90115: xsk: fix NULL pointer dereference in __xsk_rcv()
Date: Thu, 17 Sep 2026 17:09:05 +0100 [thread overview]
Message-ID: <2026091716-CVE-2026-90115-bb2c@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
xsk: fix NULL pointer dereference in __xsk_rcv()
In the __xsk_rcv() multi-buffer path, xsk_buff_alloc() is called in a
loop without checking its return value. xsk_buff_can_alloc() only
counts fill queue entries without validating their addresses, so it
can succeed while xsk_buff_alloc() rejects all remaining entries and
returns NULL.
Oops: general protection fault, probably for non-canonical address
0xdffffc0000000000
KASAN: null-ptr-deref in range
[0x0000000000000000-0x0000000000000007]
RIP: 0010:__xsk_rcv+0x426/0xc20 (net/xdp/xsk.c:350)
Call Trace:
xsk_generic_rcv+0x26d/0x5f0
xdp_do_generic_redirect+0x3c5/0xcf0
do_xdp_generic+0x92f/0xe70
__netif_receive_skb_core.constprop.0+0xf7e/0x2b30
Fix this with a two-stage transaction. First allocate and stage all
buffers required for the packet, recycling all staged buffers with
xsk_buff_free() if any allocation fails. Only after this stage
succeeds, copy the data, reserve the RX descriptors, and release the
buffers in an error-free loop.
The Linux kernel CVE team has assigned CVE-2026-90115 to this issue.
Affected and fixed versions
===========================
Issue introduced in 6.6 with commit 804627751b4281dd95148e7564759145da67855e and fixed in 6.6.157 with commit aaebce297efc3e3dccb98a6ff838cfaa47db08db
Issue introduced in 6.6 with commit 804627751b4281dd95148e7564759145da67855e and fixed in 6.12.110 with commit 60d7d3559ce66e227e195e9463cdfed8077c8659
Issue introduced in 6.6 with commit 804627751b4281dd95148e7564759145da67855e and fixed in 6.18.52 with commit 214fb79b0379cb0214905632a2537c0c33f594eb
Issue introduced in 6.6 with commit 804627751b4281dd95148e7564759145da67855e and fixed in 7.2.6 with commit 8341bd3ff126d85bc8c4ed52eedcaa5b1a65f194
Issue introduced in 6.6 with commit 804627751b4281dd95148e7564759145da67855e and fixed in 7.3-rc1 with commit e37b2abca80473e106176e41712a369fd2f72117
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-2026-90115
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:
net/xdp/xsk.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/aaebce297efc3e3dccb98a6ff838cfaa47db08db
https://git.kernel.org/stable/c/60d7d3559ce66e227e195e9463cdfed8077c8659
https://git.kernel.org/stable/c/214fb79b0379cb0214905632a2537c0c33f594eb
https://git.kernel.org/stable/c/8341bd3ff126d85bc8c4ed52eedcaa5b1a65f194
https://git.kernel.org/stable/c/e37b2abca80473e106176e41712a369fd2f72117
reply other threads:[~2026-09-17 16:15 UTC|newest]
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