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 2B5923101BF for ; Wed, 24 Jun 2026 16:33:22 +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=1782318803; cv=none; b=g5zSycGkBtDoTb1TapWAaSPc6bUANm/ML1OcBbGLTKP/IZkp7vAXOdZLkdlhwXVY9G+mYCdYfMMxUT+F8NsqaUMbZbnKl1Qep2CdbdUvo0L0iWf8pHlHgjoO5CtesLCzKRSvsW0Rp3G/Goq7Y4J9+bBgUBvumQHRNbWHjk80VNI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782318803; c=relaxed/simple; bh=8J159zdnSX+LNvO1uZUGrkBxDlnx+aj+UkiRy6x9wxA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=no0r+WWFU4BYPJ/sJiWPled9ODMni6tfGNGtMZFMNEJahW7VdkqRoJdasvRC171atIQxZyAfln3pxXu+5firiCRBdFPVQarJYkoYswgatK/EhDFNjFDCZT1MrKLS3t/+PwDCd9lVx8hmvfNhy8oDv9bKtvmShGSA9nnSAReivTY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XmuoruAK; 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="XmuoruAK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7275A1F000E9; Wed, 24 Jun 2026 16:33:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1782318802; bh=gOOjxtK/rW+SJVhJS4ZIyy15drLNHpUts8HbH3N96EU=; h=From:To:Cc:Subject:Date:Reply-To; b=XmuoruAKAXbJW2auRtww+zByfk3hs6Hy7WF4EPl2KWeIp1Pn8+8QXNv5CPINwSmCR 2YpERCAOErTsirR1XLjzEho8hYStAmGsJ7JaA5RWVq3qG91izqm3KWadTfnB8/6w+h 6zdwvDXmDWg6HLUe9Nzj/dKPlCkVIwRT1DM9ljZc= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-52981: neigh: let neigh_xmit take skb ownership Date: Wed, 24 Jun 2026 17:30:05 +0100 Message-ID: <2026062441-CVE-2026-52981-dce5@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=3236; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=MbCaqNwBSxLeDw/SBymPSG+54OTi4Trt7VsS/oUd6sA=; b=owGbwMvMwCRo6H6F97bub03G02pJDFk2rN+sdvVKHzjP/2jKKwG9HanbtLRtDhqwLF7dIJdQm yHV+GFCRywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAExEIJhhnqU1R0jrm/iXR9vD Jz9NzNrodmGFDsM8zQNhVnlVdk+d1Pw+fr7Tz8V09MpsAA== 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: neigh: let neigh_xmit take skb ownership neigh_xmit always releases the skb, except when no neighbour table is found. But even the first added user of neigh_xmit (mpls) relied on neigh_xmit to release the skb (or queue it for tx). sashiko reported: If neigh_xmit() is called with an uninitialized neighbor table (for example, NEIGH_ND_TABLE when IPv6 is disabled), it returns -EAFNOSUPPORT and bypasses its internal out_kfree_skb error path. Because the return value of neigh_xmit() is ignored here, does this leak the SKB? Assume full ownership and remove the last code path that doesn't xmit or free skb. The Linux kernel CVE team has assigned CVE-2026-52981 to this issue. Affected and fixed versions =========================== Issue introduced in 4.1 with commit 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62 and fixed in 6.1.175 with commit 8a89054a1ec0767aec25ed2bbac933da6ba3cf5a Issue introduced in 4.1 with commit 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62 and fixed in 6.6.141 with commit 9247d59ca15bf60a57dca08103f055d8a4340877 Issue introduced in 4.1 with commit 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62 and fixed in 6.12.91 with commit 0084712e0bee204b284510cdb63182fd5a30c2b7 Issue introduced in 4.1 with commit 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62 and fixed in 6.18.33 with commit 63063ba60d2dc334e34f1e3f9271d7f3f6f30307 Issue introduced in 4.1 with commit 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62 and fixed in 7.0.10 with commit 445e45a2c3a078316a62d2d331a570cf34ef5079 Issue introduced in 4.1 with commit 4fd3d7d9e868ffbdb0e7a67c5c8e9dfdcd846a62 and fixed in 7.1 with commit 4438113be604ee67a7bf4f81da6e1cca41332ce4 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-2026-52981 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/core/neighbour.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/8a89054a1ec0767aec25ed2bbac933da6ba3cf5a https://git.kernel.org/stable/c/9247d59ca15bf60a57dca08103f055d8a4340877 https://git.kernel.org/stable/c/0084712e0bee204b284510cdb63182fd5a30c2b7 https://git.kernel.org/stable/c/63063ba60d2dc334e34f1e3f9271d7f3f6f30307 https://git.kernel.org/stable/c/445e45a2c3a078316a62d2d331a570cf34ef5079 https://git.kernel.org/stable/c/4438113be604ee67a7bf4f81da6e1cca41332ce4