From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793831936; b=g3vnGfDCxPIzFbt4ASFY0DyDkAK65ihy88iwv7RKM0YRaZUZNuMeGn6VD3Jy0w/YTPei Plc7OsW9jGDbH/a+seHpPuYXL4Y8wzGANH3SXi8tEi4+e41sY772KooYGiJDNW6pYRdf5 156nt+di78to2W9LdL2WVQ6pD73DY7loGu2N9qRgySKARU0QxWWqqx6wcYWrumhqPffVw qwehEChlZy89MiwmnMwHuVM0pgPD2N69zzWhC5+FaVNc35uyS1P94+QMKjZ5ln2958Btd fNfCJ/OFo2Q13Q8l7oMrV9ZppoB6vVVrFVkfC8Xa931tIpgTTqyUYi3ZrBZirGrQeKA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793831936; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=I0xZ78QHlNrGPrYTmUysK/WGIlOS7DCqotoQoh7/jRo=; b=mjRVYQqHVntkr/8urM45LmrdxlsFsmlDDv94Wl0I05h21ykWQd4Yj+aTHz3dAlzlrG94 DEKt+S+FG6owACK512jZNgYpIueHrsMXX9yVx0+FJw5PzEYiGaCjbpCZU/T7HcrPsZ/mh sKgMZBvKjKUEkH44D7mjZEMYGuH/LRrLq1NbOzfJO7hq0Tl89seBaabKj3NjjzlvD7Rnt jSWoy0LA30c8E3oOolf1viRvOpLooT2Q+GtleQmSYCYzeO41oHwNw9k7PVJijjp+dGX9z ks0BUTBITvDHeb1VXhzc3O+NFuHGpDuC9CgtaY8a5JMJuEAOkZ7+xsamPn5AJtaqT8Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=GyC2Ah8F; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD2ED606A328; Wed, 4 Nov 2026 22:38:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=GyC2Ah8F Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6754E1F000C1; Wed, 4 Nov 2026 22:38:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793831935; bh=I0xZ78QHlNrGPrYTmUysK/WGIlOS7DCqotoQoh7/jRo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GyC2Ah8FaiNa77bFHFv74izY+3Lw2pNKasl5uc28k2gq3bi/5h5F7VtUIah1/xP9f DZb4GW2kFSGWkuhcLt8MIDAvdt6XlTW+RfhKXmmVnliFvPoJ6gaJ7Zz8mOwa6mSjp8 aD73iRwxbPTZ6HmLQDNHLVmbVZUWeBX8isOPOzKY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zikang Gao <2715417602@qq.com>, David Howells , Paulo Alcantara , Sasha Levin Subject: [PATCH 6.18 0982/1005] smb: client: do not pass a NULL buf to is_oplock_break() Date: Wed, 4 Nov 2026 16:11:55 -0500 Message-ID: <20261104211110.553210933@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zikang Gao <2715417602@qq.com> [ Upstream commit 2225ab306575e424b3dad2ee1be2521c89249d15 ] receive_encrypted_read() sets *num_mids = 1 and never writes the caller's bufs[]. Offload returns -1 with *num_mids = 0, so the demultiplex thread skips the frame. The inline decrypt path returns 0 even when smb2_find_mid() fails. cifs_demultiplex_thread() then treats mids[i] == NULL as an oplock break and calls is_oplock_break(bufs[i], server) with bufs[i] still NULL. smb2_is_valid_oplock_break() reads hdr.Command at offset 12 and oopses. A large encrypted READ whose MessageId does not match is enough to panic cifsd. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 100 Comm: cifsd RIP: smb2_is_valid_oplock_break+0xc8/0x2270 [cifs] cifs_demultiplex_thread Kernel panic - not syncing: Fatal exception Return -1 when inline decrypt finds no mid, and skip is_oplock_break() plus the unknown-frame dump when bufs[i] is NULL. receive_encrypted_standard() already assigns bufs[*num_mids]. Fixes: c42a6abe3012 ("CIFS: Add capability to decrypt big read responses") Assisted-by: LLM Signed-off-by: Zikang Gao <2715417602@qq.com> Reviewed-by: David Howells Signed-off-by: Paulo Alcantara Cc: stable@vger.kernel.org [ sashal: Adjusted context to retain the existing one-argument mid_execute_callback() and release_mid() calls. ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/connect.c | 4 +++- fs/smb/client/smb2ops.c | 1 + 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index e908d522920c8..ca71026799e0c 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -1400,12 +1400,14 @@ cifs_demultiplex_thread(void *p) mid_execute_callback(mids[i]); release_mid(mids[i]); - } else if (server->ops->is_oplock_break && + } else if (bufs[i] && server->ops->is_oplock_break && server->ops->is_oplock_break(bufs[i], server)) { smb2_add_credits_from_hdr(bufs[i], server); cifs_dbg(FYI, "Received oplock break\n"); } else { + if (!bufs[i]) + continue; cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n", atomic_read(&mid_count)); cifs_dump_mem("Received Data is: ", bufs[i], diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index 5ad3804826d9a..702e32e0e51ad 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -5357,6 +5357,7 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid, *mid = smb2_find_mid(server, buf); if (*mid == NULL) { cifs_dbg(FYI, "mid not found\n"); + rc = -1; } else { cifs_dbg(FYI, "mid found\n"); (*mid)->decrypted = true; -- 2.53.0