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 5DA7C35C682; Tue, 21 Jul 2026 22:27:37 +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=1784672858; cv=none; b=OUJpgb0m8Am9XO3beXV9JYCMzQq8RKf143ZKV84yhg9hkf5T5UdqAY4Que8cb+mLG21bQaGf7Pg/nQ9YVuZBpA3SlY0eZRwSENYTJJPaxEYpuXSvmH+mQD3KtXzq80HX5/z2UiMzeAB9oN/QLSmrWy1WW6R2LLD49cL7EUzN41A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784672858; c=relaxed/simple; bh=yLjSsTnsRB/RS5+ZFTlbYSb9atISxtYViAPpvgln2DU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=s6uA5nLmSklMorDgfq0K7K9wn4EDU/2jScYjFb9He0lTxaNF1NhbnsENE/6ma7SW8b3sjOe2D4mX0ZdJlJFZPX4BM+gTCW4M7d2pLb6guigkRsdXqgwajPXkx47Me76GC6T/KBnyDoWgD7kG+4aEXTWItdn6uCfnuBh/mI5Kmpg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lRBZDgjW; 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="lRBZDgjW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 834A31F000E9; Tue, 21 Jul 2026 22:27:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784672857; bh=/s/WHUd+Kyp5dBe0cw4gW38L0egL8MIH4x05blRK3gY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lRBZDgjWZxZ8RVB0VvH9P3JJsjgoTd2DGdtD8PDb6tASvtnDczY4xuie+XvBsDpVX R5jhI7WonJ5eWU0Hw1PmL9eVTq6CESnu+foVLRnzCZEgoKQTqexzULx0JFD5uZ7a/S sG3dBv3yZ9lgX0Snc9eXGTld6DHMQyhFYC0It8nI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuan Tan , Yifan Wu , Juefei Pu , Xin Liu , Zihan Xi , Ren Wei , Steve French , Sasha Levin Subject: [PATCH 5.15 784/843] smb: client: harden POSIX SID length parsing Date: Tue, 21 Jul 2026 17:26:59 +0200 Message-ID: <20260721152423.696618504@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152405.946368001@linuxfoundation.org> References: <20260721152405.946368001@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zihan Xi [ Upstream commit 7ad2bcf2441430bb2e918fb3ef9a90d775a6e422 ] posix_info_sid_size() reads sid[1] to obtain the subauthority count, but its existing boundary check still accepts buffers with only one remaining byte. Require two bytes before reading sid[1] so all client paths that reuse the helper reject truncated POSIX SIDs safely. Fixes: 349e13ad30b4 ("cifs: add smb2 POSIX info level") Cc: stable@vger.kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi Signed-off-by: Ren Wei Signed-off-by: Steve French Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/cifs/smb2pdu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -4592,7 +4592,7 @@ int posix_info_sid_size(const void *beg, size_t subauth; int total; - if (beg + 1 > end) + if (beg + 2 > end) return -1; subauth = *(u8 *)(beg+1);