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 8F9B53101BF for ; Wed, 24 Jun 2026 16:34:05 +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=1782318846; cv=none; b=iYq30kAi4P2n0twwNVp+R+G0J3btNUccCymsnWtYUAUOfyyn6Yd+hdqL0K3WmWFxWOzYltEJoDmYcMhsE/6RyCQSMcB9AJLTuNdpWpbZxb/ZY8Afv34NakDmthQcR049MvZz2yfNNz/liR4CqST/2MkO5xGWt1QOB/+x+7XUaVU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782318846; c=relaxed/simple; bh=pQjaGyHgnsEfRjm7t0zzFgKgKUEG9HvW/8GA65yVyyE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=AaRdDc9puQFNncd+jzbfBO94iqJ/++YOBpJRgyUBH/F6HWNI7IleTGfcNpPBfKmGmrVmtykZavVUxEq/IH4p/7Od3aQGNaiRyD8sGfXEkb5B0s1Yv29Uu9Vy3BPzrh3++jXGh9gkVaEytwQOInEoSIByC6zSBqE3IAK2D7HqF6w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UyTnvw9w; 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="UyTnvw9w" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C564E1F000E9; Wed, 24 Jun 2026 16:34:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1782318845; bh=x7EvLr2N/1nQGEXphxKKmZ+nNJm4rzeeljAEjPXU38U=; h=From:To:Cc:Subject:Date:Reply-To; b=UyTnvw9wRmTtCkS9dEiAvtzg7SrcP8trG2d9T2cVC/9S7ZdYRRLvHNqnQN/huacwM eOJ8G0uCTXldvpkk1UAgNuX9H9ASaENM2D54LfT2SCj1K0vyXClRJERKTdABc1CkhK T3s38BfLdsxAIitHgMJju9qPJ/gkHJdfEcernZYw= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-52993: tipc: fix double-free in tipc_buf_append() Date: Wed, 24 Jun 2026 17:30:17 +0100 Message-ID: <2026062445-CVE-2026-52993-34a2@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=3661; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=QrvqjiOv4JuErHS6E0u/iUets6YZYPG5RjaHqZ5imQ0=; b=owGbwMvMwCRo6H6F97bub03G02pJDFk2rD//X1LkFRTdOdtj1vJHObxPJs8IuDLxy8wk0YojV TwBe8wnd8SyMAgyMciKKbJ82cZzdH/FIUUvQ9vTMHNYmUCGMHBxCsBEQtoZFkw8uHLnzxvFLLIM mj0PVIzLO0J2ZDDMMzRjlv5685mzlbBLxTzfc1cV7SbHAwA= 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: tipc: fix double-free in tipc_buf_append() tipc_msg_validate() can potentially reallocate the skb it is validating, freeing the old one. In tipc_buf_append(), it was being called with a pointer to a local variable which was a copy of the caller's skb pointer. If the skb was reallocated and validation subsequently failed, the error handling path would free the original skb pointer, which had already been freed, leading to double-free. Fix this by checking if head now points to a newly allocated reassembled skb. If it does, reassign *headbuf for later freeing operations. The Linux kernel CVE team has assigned CVE-2026-52993 to this issue. Affected and fixed versions =========================== Issue introduced in 4.15 with commit d618d09a68e4eed7a435beb2e355250f6f40664a and fixed in 5.10.258 with commit a438975a6dcdbd70865978c021650d1485586f0b Issue introduced in 4.15 with commit d618d09a68e4eed7a435beb2e355250f6f40664a and fixed in 5.15.209 with commit 4ee4deadaae7cb2e3d53af0fc889cf92a73413c0 Issue introduced in 4.15 with commit d618d09a68e4eed7a435beb2e355250f6f40664a and fixed in 6.1.175 with commit d3556656c6daebf8def751c7e71d11dd0a180d24 Issue introduced in 4.15 with commit d618d09a68e4eed7a435beb2e355250f6f40664a and fixed in 6.6.141 with commit 0274f24485fc38032d4093e463dc3ff5c7a667c9 Issue introduced in 4.15 with commit d618d09a68e4eed7a435beb2e355250f6f40664a and fixed in 6.12.91 with commit 4d104882bc815d4ec666ace9155f5f52715879a6 Issue introduced in 4.15 with commit d618d09a68e4eed7a435beb2e355250f6f40664a and fixed in 6.18.33 with commit 1d5e589055880fae229e229e1929e087dbe08cf3 Issue introduced in 4.15 with commit d618d09a68e4eed7a435beb2e355250f6f40664a and fixed in 7.0.10 with commit 29940fff14110ca48c5ccc168d121665b51bb778 Issue introduced in 4.15 with commit d618d09a68e4eed7a435beb2e355250f6f40664a and fixed in 7.1 with commit d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a 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-2026-52993 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/tipc/msg.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/a438975a6dcdbd70865978c021650d1485586f0b https://git.kernel.org/stable/c/4ee4deadaae7cb2e3d53af0fc889cf92a73413c0 https://git.kernel.org/stable/c/d3556656c6daebf8def751c7e71d11dd0a180d24 https://git.kernel.org/stable/c/0274f24485fc38032d4093e463dc3ff5c7a667c9 https://git.kernel.org/stable/c/4d104882bc815d4ec666ace9155f5f52715879a6 https://git.kernel.org/stable/c/1d5e589055880fae229e229e1929e087dbe08cf3 https://git.kernel.org/stable/c/29940fff14110ca48c5ccc168d121665b51bb778 https://git.kernel.org/stable/c/d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a