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 5D8EE39A054 for ; Sun, 19 Jul 2026 15:45:42 +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=1784475943; cv=none; b=CAIR24JEtUrlNLBwW0PfikwVvbMGlscReIMgo9k8WyQV2NFc6TSIN7Mo5nI3DySt52b1GL4zClTvSuJcFu5jVUxHTwjzlfbMKDqjrq1bjXR8r/+fDig8nRpQ7ZUntb+98pPXjrAlPXO3Ak/5rECo8dQw+UfYzPrEsywRZHKBwGU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784475943; c=relaxed/simple; bh=cVzx68k7exLDMoeqVVi//nCG/8s2C8bEn5FkXOfzXVk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=ceKtNGEsbefMtlHJnTeYDJ2vRljI/iU53lacOXpptRHz+ECHpv3LoBmc+q9M2qysPvCeIXNgpSZ59/fa+PHDM6Ep/J1TjqArvNedACHRXKlpDiFUW+l1aP/kFmBA6jM1VudC8KGh4DfNZkBX7FKStB3LOw2N8+N5GJId2qis/uI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cKzDrpeD; 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="cKzDrpeD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2FFA1F000E9; Sun, 19 Jul 2026 15:45:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784475942; bh=3fnf9f698AiUjxfFSN+ZmdLpp0VOOY9sl6qffkbQ4eo=; h=From:To:Cc:Subject:Date:Reply-To; b=cKzDrpeD0aluz98vOXAr+UvKw1h750GAEkIMTt3jY8d5CndOOKWogMflqxHmXtbF2 lbBxmJ8Dt4WDFfhqJU5I8mYBgjXaV1g9zlE73JIbrg+Ko9is6ufPH5snvO9LSvQE2+ 30GGqWnZfhgiBEFTEY5GLhNxw2AG971fvUr0zwuY= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-64141: ksmbd: fix null pointer dereference in compare_guid_key() Date: Sun, 19 Jul 2026 17:40:03 +0200 Message-ID: <2026071929-CVE-2026-64141-2e37@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=4182; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=6UQxWx3O0B1OBiuJ7721AP36XdKz2aSbSZMKizxG+3Q=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkx70uj3i9LOXSUQ+1r2T2jTw9/cW+Ptvp6aPHmfks2p ehdxz8VdcSyMAgyMciKKbJ82cZzdH/FIUUvQ9vTMHNYmUCGMHBxCsBEJvIyzM8LEzk1K+tLV9NM PTO/HTG/np7/+YxhnvaDvGV8v1/r2Xe8CF/YdiPmls6dBgA= 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: ksmbd: fix null pointer dereference in compare_guid_key() session_fd_check() walks the per-inode m_op_list during durable-handle session teardown and sets op->conn = NULL for every opinfo whose conn matched the closing session's connection. The matching opinfo, however, stays linked in its per-ClientGuid lease_table_list entry's lb->lease_list because destroy_lease_table() only runs on full TCP-connection teardown, not on SESSION_LOGOFF. If the same TCP connection then negotiates a fresh session with the same ClientGuid (ClientGuid is bound to NEGOTIATE, not the session, and is unchanged across LOGOFF + SETUP) and issues a SMB2 CREATE with a lease context on a different inode, find_same_lease_key() walks lb->lease_list, reaches the stale opinfo, and calls compare_guid_key(), which unconditionally dereferences opinfo->conn->ClientGUID. The conn pointer is NULL and the kernel panics. Reproducer requires only a successful SMB2 SESSION_SETUP and a share configured with 'durable handles = yes'. KASAN report on mainline 70390501d194: general protection fault, probably for non-canonical address 0xdffffc0000000069: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000348-0x000000000000034f] Workqueue: ksmbd-io handle_ksmbd_work RIP: 0010:bcmp+0x5b/0x230 Call Trace: compare_guid_key+0x4b/0xd0 find_same_lease_key+0x324/0x690 smb2_open+0x6aea/0x8e60 handle_ksmbd_work+0x796/0xee0 ... Faulting address 0x348 is the offset of ClientGUID within struct ksmbd_conn, confirming opinfo->conn was NULL. Read opinfo->conn once and bail out if it has been cleared by a concurrent session_fd_check(). A half-detached opinfo cannot be the owner of an active lease, so returning 0 is the correct match result. The Linux kernel CVE team has assigned CVE-2026-64141 to this issue. Affected and fixed versions =========================== Issue introduced in 6.6.32 with commit 8df4bcdb0a4232192b2445256c39b787d58ef14d and fixed in 6.6.142 with commit e43cb36d4d7827710cfcd48e95e29a507f0d87be Issue introduced in 6.9 with commit c8efcc786146a951091588e5fa7e3c754850cb3c and fixed in 6.12.92 with commit 0836081b394ca074d1b910f2b990ff7b4b4404c7 Issue introduced in 6.9 with commit c8efcc786146a951091588e5fa7e3c754850cb3c and fixed in 6.18.34 with commit cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad Issue introduced in 6.9 with commit c8efcc786146a951091588e5fa7e3c754850cb3c and fixed in 7.0.11 with commit af86896ca3239e25a6bd7d352213371265073d38 Issue introduced in 6.9 with commit c8efcc786146a951091588e5fa7e3c754850cb3c and fixed in 7.1 with commit 4b83cbc4c15f09b000cc06f033f64b0824b6dc87 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-2026-64141 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/server/oplock.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/e43cb36d4d7827710cfcd48e95e29a507f0d87be https://git.kernel.org/stable/c/0836081b394ca074d1b910f2b990ff7b4b4404c7 https://git.kernel.org/stable/c/cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad https://git.kernel.org/stable/c/af86896ca3239e25a6bd7d352213371265073d38 https://git.kernel.org/stable/c/4b83cbc4c15f09b000cc06f033f64b0824b6dc87