From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DC63B38C2C3 for ; Wed, 24 Jun 2026 07:15:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782285307; cv=none; b=XH9S6e5tlp/4rhxJLB+GPI5sfdadkTLoCgFd+gqMI3ODtpXw00yv+7eREDhhikVxH+iOtkDgS9ytkr9yndMjQtQcWfnY8CfOGYkO88+zhJA3DESd/8tk3vAJd0pMcg/ok5tY2VHGeQZMUMFYty1M+Qz3rpSyILeYTJ6l3HS15Z4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782285307; c=relaxed/simple; bh=3wXRvGEk34agm4006i3ygCMEoCH8BmH3pRM+AGM6nLQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=SXtfnOW0RiaNap1pRrbCFjMlQsfaM4FbqdYcsDa9Sd6gw2IKR3eSxTzYUfBPBei5lT/ImgDEGNMlAkgWw6d4g8cnb7SsyehZYJGMUyCjIpP59s4yAa5u1gLU4wsMl8Sk2LJIehNOBYCuo8c2FDaABOQckuxfiZdcli1pqpxiGzQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=F1G9KXY5; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="F1G9KXY5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE1471F000E9; Wed, 24 Jun 2026 07:15:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1782285305; bh=uIgWg6z0ku0plvY2brB5zb5bB/VLE15v/600m8pt6fk=; h=From:To:Cc:Subject:Date:Reply-To; b=F1G9KXY5yUuLxNfJg3hh6pRSdfwICg5cYPPbD0Aulj1S/0BHPJSNaFDs8Qp4T8OJR DZLmiHI24XViYjql6DUqD375iZAepOrHqqGzcxw+06UoLGxDhDOX8HTCvPBaCVHL62 e2D5rLFeZUl8rqPBYuAefO3dnWdE7yAMbNjR5/8w= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-52925: vrf: Fix a potential NPD when removing a port from a VRF Date: Wed, 24 Jun 2026 09:13:40 +0200 Message-ID: <2026062431-CVE-2026-52925-3307@gregkh> X-Mailer: git-send-email 2.54.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4696; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=N4eIHmC2TqlyLAoVSeW/71E/fiRw3aVF5UmFuxCTUoE=; b=owGbwMvMwCRo6H6F97bub03G02pJDFnWzbPP/Kj0W3UgPSCwR9dI0+kpZ+Om5u+shk0t9VFdO pcav6Z0xLIwCDIxyIopsnzZxnN0f8UhRS9D29Mwc1iZQIYwcHEKwER+LGFYsOC6afJeTZM3qu8k bjB4e2d//rongGGexWPxb4cdbX0aeLcGCzy2V1Y3lVwOAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: vrf: Fix a potential NPD when removing a port from a VRF RCU readers that identified a net device as a VRF port using netif_is_l3_slave() assume that a subsequent call to netdev_master_upper_dev_get_rcu() will return a VRF device. They then continue to dereference its l3mdev operations. This assumption is not always correct and can result in a NPD [1]. There is no RCU synchronization when removing a port from a VRF, so it is possible for an RCU reader to see a new master device (e.g., a bridge) that does not have l3mdev operations. Fix by adding RCU synchronization after clearing the IFF_L3MDEV_SLAVE flag. Skip this synchronization when a net device is removed from a VRF as part of its deletion and when the VRF device itself is deleted. In the latter case an RCU grace period will pass by the time RTNL is released. [1] BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] RIP: 0010:l3mdev_fib_table_rcu (net/l3mdev/l3mdev.c:181) [...] Call Trace: l3mdev_fib_table_by_index (net/l3mdev/l3mdev.c:201 net/l3mdev/l3mdev.c:189) __inet_bind (net/ipv4/af_inet.c:499 (discriminator 3)) inet_bind_sk (net/ipv4/af_inet.c:469) __sys_bind (./include/linux/file.h:62 (discriminator 1) ./include/linux/file.h:83 (discriminator 1) net/socket.c:1951 (discriminator 1)) __x64_sys_bind (net/socket.c:1969 (discriminator 1) net/socket.c:1967 (discriminator 1) net/socket.c:1967 (discriminator 1)) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) The Linux kernel CVE team has assigned CVE-2026-52925 to this issue. Affected and fixed versions =========================== Issue introduced in 4.12 with commit fdeea7be88b12742bfd50d9e19a06c0d2e702400 and fixed in 5.10.258 with commit 2c022f582fd16a470df6ed9e7fb7e9fc48946d49 Issue introduced in 4.12 with commit fdeea7be88b12742bfd50d9e19a06c0d2e702400 and fixed in 5.15.209 with commit 4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4 Issue introduced in 4.12 with commit fdeea7be88b12742bfd50d9e19a06c0d2e702400 and fixed in 6.1.175 with commit 468defa0b70902a22f4478c1207624bc1b31c124 Issue introduced in 4.12 with commit fdeea7be88b12742bfd50d9e19a06c0d2e702400 and fixed in 6.6.141 with commit 3db8d078f7f652379ee394132b169d304f6eb4c1 Issue introduced in 4.12 with commit fdeea7be88b12742bfd50d9e19a06c0d2e702400 and fixed in 6.12.91 with commit 8c2b792f04a3db97c9d8d2a45817e93f8884baf5 Issue introduced in 4.12 with commit fdeea7be88b12742bfd50d9e19a06c0d2e702400 and fixed in 6.18.33 with commit a7a97f2303e63ede105c1d55ef53dc497364e11d Issue introduced in 4.12 with commit fdeea7be88b12742bfd50d9e19a06c0d2e702400 and fixed in 7.0.10 with commit d47204c127992da0c976ac9747070a575912e0fe Issue introduced in 4.12 with commit fdeea7be88b12742bfd50d9e19a06c0d2e702400 and fixed in 7.1 with commit 2674d603a9e6970463b2b9ebcf8e31e90beae169 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-2026-52925 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/vrf.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/2c022f582fd16a470df6ed9e7fb7e9fc48946d49 https://git.kernel.org/stable/c/4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4 https://git.kernel.org/stable/c/468defa0b70902a22f4478c1207624bc1b31c124 https://git.kernel.org/stable/c/3db8d078f7f652379ee394132b169d304f6eb4c1 https://git.kernel.org/stable/c/8c2b792f04a3db97c9d8d2a45817e93f8884baf5 https://git.kernel.org/stable/c/a7a97f2303e63ede105c1d55ef53dc497364e11d https://git.kernel.org/stable/c/d47204c127992da0c976ac9747070a575912e0fe https://git.kernel.org/stable/c/2674d603a9e6970463b2b9ebcf8e31e90beae169