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=1793901026; b=fZREWGF1qFrqaPVH1QGfCb1g6fBzwcaePOtG0N5YY60EamNBa8gD5NGI7hdfK+7rUxX6 KMpwjnZOtY3gP8kMiSMsgXGqcSBWMbsvR75HBdO8J0bb+VgY47t6+qcowDQasSyX8tljj eef6xcaO/f9vMUS9QAlgH/oc0PbiD25VOZGN59dL0jhYbvqLZWO59lDP1A3dbXzj47oTJ xwvrGOAU+d83zgt73jAfGlhngQlAm+vbjm3pmMYda1ng6y4BG8aIhug/Zz5TewSSnQE/U Wd+kW9fzC0P4wgOGdBImqHHlFjfhXgN7hXxNZEz/R7meAw6bx6BK699V95huZS1ax9Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793901026; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=sXt2+U/+wuZRkL7GsFFQurxO0OxNvpNqXIqSluDEFUQ=; b=va7xqWVFwpENPWwc24TsbKkcCoXt6vy3eTUFG3KXVPZE9b+z/NQPX8ge4N+mQa+I2jLZ Og6KBYTSELi43Ofb0470iGDQUIs59oXCRajFZHj7fBZJjI0K+8957ZL6rYZEKiiYXloim xgjSznLnV3hwtDrMkMb3XG2AtdgszLEfh+HbQKbAF1dTQl/o4Rs8DOvGK5oiinn1R+MuO jfsf/r8GcntHD6XbZ0pGZ0pMklvBlKJEoVE9HaiYg9Jau1Vycqzi0v+Xuk5XXzEuQzyjk yzw1ds6Cpu3OxoushtmRabfTYtKX4h3AfnzNGtSuCmvt07WvemflyqbNv4SyElfMm7w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=NRbQUCoh; 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 1EF8D606A31B for ; Thu, 5 Nov 2026 17:50:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=NRbQUCoh Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73FEE1F000C1; Thu, 5 Nov 2026 17:50:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793901026; bh=sXt2+U/+wuZRkL7GsFFQurxO0OxNvpNqXIqSluDEFUQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NRbQUCohZ3ClRKApvnNVw5nBWxE4YvJYf1L+H5zstIC1mN2aYeeQ+jInLhQDohoU3 f0qws8PIgq/vFrcAP59wsjjs/V0bkivThB1X1Ld9cfd2pm1hAzfTT5KzXrvprboch7 kIAf7/zKVfwKlZbxb2Fo5pgzECOblNqiJMCny5uTi33uxjjNHgDOT8ASq7P03oXxfH m7h2VJ7FL0DOMpxq0NGTsla8mjDK7CiYWW0U/fmIqoTJQzv2deEsg6vxjstJ/LGNEU lIi30Za+hx0ouUxVPs+i+NPagwXN7mECqzd0lwhrivBlkK/OTyj9rcNR6Mhg0Qz5Jv 75NVqmh6am2vQ== From: Sasha Levin To: stable@vger.kernel.org Cc: VeroFess , Namjae Jeon , Sasha Levin Subject: [PATCH 6.1.y] smb: server: size directory name conversion buffer correctly Date: Thu, 5 Nov 2026 12:50:24 -0500 Message-ID: <20261105175003.2184217-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026110424-hypnoses-average-6482@gregkh> References: <2026110424-hypnoses-average-6482@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: VeroFess [ Upstream commit f1f37834eaba5904103af1f18afe3510c7e9dc71 ] A 2048-byte ASCII directory name needs 4098 bytes when converted to UTF-16, including the terminator. ksmbd_convert_dir_info_name() caps its allocation at PATH_MAX and writes past the end of that buffer. Allocate space for one UTF-16 code unit per input byte plus the terminator. Use kmalloc_array() to check the size calculation. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Assisted-by: gpt 6 sol with daybreak blue Signed-off-by: VeroFess Signed-off-by: Namjae Jeon [ sashal: used GFP_KERNEL instead of KSMBD_DEFAULT_GFP for kmalloc_array() ] Signed-off-by: Sasha Levin --- fs/smb/server/misc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/smb/server/misc.c b/fs/smb/server/misc.c index 98da57bb5fd29..ea6eccbe81bb9 100644 --- a/fs/smb/server/misc.c +++ b/fs/smb/server/misc.c @@ -289,12 +289,13 @@ char *ksmbd_convert_dir_info_name(struct ksmbd_dir_info *d_info, int *conv_len) { char *conv; - int sz = min(4 * d_info->name_len, PATH_MAX); - if (!sz) + if (d_info->name_len <= 0) return NULL; - conv = kmalloc(sz, GFP_KERNEL); + /* One UTF-16 code unit per input byte, plus the terminating NUL. */ + conv = kmalloc_array((size_t)d_info->name_len + 1, + sizeof(__le16), GFP_KERNEL); if (!conv) return NULL; @@ -303,7 +304,6 @@ char *ksmbd_convert_dir_info_name(struct ksmbd_dir_info *d_info, d_info->name_len, local_nls, 0); *conv_len *= 2; - /* We allocate buffer twice bigger than needed. */ conv[*conv_len] = 0x00; conv[*conv_len + 1] = 0x00; return conv; -- 2.53.0