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 9D110235BE2 for ; Sun, 19 Jul 2026 15:45:28 +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=1784475929; cv=none; b=Ukde3aPqeJNwHri3z6AfAIGE3pqESGqbckTeu1e1XDsxep79JE1aFEEmBjHwg1eSyV1CcTu+SKsyAlrYl9xxbMXMpdlItb7tFYUFvVqAIQtuOcHW4+tbVXRsf9aoxHmYfIMK8TctWggWdo3WzX4rv2zwO9eujDs6meE9dn60kv4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784475929; c=relaxed/simple; bh=bGCg+meR/T13TswZlxat4AzCMU4JuNCsURWp0gXbfjU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=KpbAEOo65OLn0RCm3ZctNXOJaw6oY6LwH5nYWLZ0AVgYXesZReqCr+YqV+2a4+bSyC8mrDBAM9prTtNFWOU8we970TF4yugvwWUrpHi9buQNwg+zjh4LjwQWdQ6q2UWOB3w+hCBf8u1juQ9/xG5i9ImdNfasbd1d64w+Jmjf6Ys= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fBd03WpH; 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="fBd03WpH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2C5A1F000E9; Sun, 19 Jul 2026 15:45:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784475928; bh=GTonEQ2xInur+jbVCE/QtbpUcJPYX73Vb3HnsU8+NbY=; h=From:To:Cc:Subject:Date:Reply-To; b=fBd03WpHG5bRZb8BQxQwnrdRwaKUtpWWUfk4w3K5VYszmgbhzVAd56mREJJmTfzLZ 29+mlqjxsdKlwLvE6KvmLQ1nhAf/fAk5pSlxuZRRQkjGInvAzXZsGW2xhdJUEBfEjl ePnggxSdXygzkoSOcBkz7kQZd920z2aCIzkRMFT8= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-64136: smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked() Date: Sun, 19 Jul 2026 17:39:58 +0200 Message-ID: <2026071928-CVE-2026-64136-5fb4@gregkh> X-Mailer: git-send-email 2.55.0 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=2812; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=W1k2GSz07LuA/1Lsd0EG7eYsQkn9c6MYLjWmodM7FjQ=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkx70ua5M5/9BV9cV3jmO/iK9NyvbLlT1ed8Fc9wdrhP nfJnvXKHbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjARU2+G+YWbWyq8PHaeWP7t 7MP4OR8nukZcqGCYny2kc8WJPeLAG/vsLs28uZG7JWeyAgA= 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: smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked() Commit 96c4af418586 ("cifs: Fix locking usage for tcon fields") refactored cifs code to change cifs_tcp_ses_lock for tc_lock around tc_count changes. There was missing lock around tc_count increment inside smb2_find_smb_sess_tcon_unlocked(). The Linux kernel CVE team has assigned CVE-2026-64136 to this issue. Affected and fixed versions =========================== Issue introduced in 6.6.128 with commit 953953abb66e52c224057ab91e404284fefeab62 and fixed in 6.6.142 with commit 7df1df6f40c0720d30206aa35c0343b962350e0d Issue introduced in 6.12.75 with commit 601dd3b79769b38d30b693c40afdb2a4b7edf9d0 and fixed in 6.12.92 with commit 13fb413ae22a37c69341918a6d651d19a9b0b9b7 Issue introduced in 6.18.16 with commit 3969db6b22e3d90d8c5f22ac1a7fe0350a94c136 and fixed in 6.18.34 with commit bf4ebdb19ff9b3cdf992b50715fe61633327416a Issue introduced in 7.0 with commit 96c4af418586ee9a6aab61738644366426e05316 and fixed in 7.0.11 with commit e374f4e496fef8168784f93a4477d67be34485fd Issue introduced in 7.0 with commit 96c4af418586ee9a6aab61738644366426e05316 and fixed in 7.1 with commit 4d8690dace005a38e6dbde9ecce2da3ad85c7c41 Issue introduced in 6.19.6 with commit 8c59eeeeffa1524ef57e173a89a1a3ff539888d5 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-2026-64136 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: fs/smb/client/smb2transport.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/7df1df6f40c0720d30206aa35c0343b962350e0d https://git.kernel.org/stable/c/13fb413ae22a37c69341918a6d651d19a9b0b9b7 https://git.kernel.org/stable/c/bf4ebdb19ff9b3cdf992b50715fe61633327416a https://git.kernel.org/stable/c/e374f4e496fef8168784f93a4477d67be34485fd https://git.kernel.org/stable/c/4d8690dace005a38e6dbde9ecce2da3ad85c7c41