smb: compress: reject Pattern_V1 when not negotiated

Pattern_V1 is an optional chained payload type selected during SMB 3.1.1
compression negotiate. conn->compress_pattern was only consulted when
building responses, so a peer that negotiated LZ77 with chained support
could still submit Pattern payloads on the receive path.

Pass allow_pattern through smb_compression_decompress() and reject
SMB3_COMPRESS_PATTERN in the chained decoder when it is false.

Link: https://github.com/namjaejeon/ksmbd/issues/529
Fixes: a08de24c2b85 ("ksmbd: negotiate and decode SMB2 compression")
Signed-off-by: Anatolii Shumak <anatoliy.shumak@gmail.com>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/common/compress/compress.c b/fs/smb/common/compress/compress.c
index b07a317597a4cf30139d879d298c0364c18d1988..a4123c8f1c0ab30ddb0f6962a88fdd5730cfc7ce 100644 (file)
--- a/fs/smb/common/compress/compress.c
+++ b/fs/smb/common/compress/compress.c
@@ -95,6 +95,7 @@ static int smb_decompress_lz77_payload(const u8 **src, u32 *slen, u8 **dst,
 }
 
 static int smb_decompress_chained(__le16 alg, bool allow_chained,
+                                 bool allow_pattern,
                                  const struct smb2_compression_hdr *hdr,
                                  u32 slen, void *dst, u32 dlen)
 {
@@ -143,6 +144,8 @@ static int smb_decompress_chained(__le16 alg, bool allow_chained,
                        rc = smb_decompress_none(&src, &remaining, &out,
                                                 &out_remaining, len);
                } else if (payload_alg == SMB3_COMPRESS_PATTERN) {
+                       if (!allow_pattern)
+                               return -EINVAL;
                        rc = smb_decompress_pattern(&src, &remaining, &out,
                                                    &out_remaining, len);
                } else if (payload_alg == alg && alg == SMB3_COMPRESS_LZ77) {
@@ -185,6 +188,7 @@ static int smb_decompress_unchained(__le16 alg,
  * smb_compression_decompress() - decode an SMB2 compression transform
  * @alg: negotiated general-purpose compression algorithm
  * @allow_chained: whether chained transforms were negotiated
+ * @allow_pattern: whether Pattern_V1 payloads were negotiated
  * @src: transform header followed by compressed payload data
  * @slen: total number of bytes available at @src
  * @dst: output buffer for the reconstructed SMB2 message
@@ -197,7 +201,8 @@ static int smb_decompress_unchained(__le16 alg,
  * Return: 0 on success, otherwise a negative errno.
  */
 int smb_compression_decompress(__le16 alg, bool allow_chained,
-                              const void *src, u32 slen, void *dst, u32 dlen)
+                              bool allow_pattern, const void *src, u32 slen,
+                              void *dst, u32 dlen)
 {
        const struct smb2_compression_hdr *hdr = src;
 
@@ -207,8 +212,8 @@ int smb_compression_decompress(__le16 alg, bool allow_chained,
                return -EINVAL;
 
        if (hdr->Flags == cpu_to_le16(SMB2_COMPRESSION_FLAG_CHAINED))
-               return smb_decompress_chained(alg, allow_chained, hdr, slen,
-                                             dst, dlen);
+               return smb_decompress_chained(alg, allow_chained, allow_pattern,
+                                             hdr, slen, dst, dlen);
 
        if (hdr->Flags != cpu_to_le16(SMB2_COMPRESSION_FLAG_NONE))
                return -EINVAL;

diff --git a/fs/smb/common/compress/compress.h b/fs/smb/common/compress/compress.h
index 7ace3bf4b664caebf09a1368e69b18e77539ca44..d6916669f88715133cec0aab8bad6ecd5afb35aa 100644 (file)
--- a/fs/smb/common/compress/compress.h
+++ b/fs/smb/common/compress/compress.h
@@ -20,7 +20,8 @@ static __always_inline bool smb_compress_alg_valid(__le16 alg, bool valid_none)
 }
 
 int smb_compression_decompress(__le16 alg, bool allow_chained,
-                              const void *src, u32 slen, void *dst, u32 dlen);
+                              bool allow_pattern, const void *src, u32 slen,
+                              void *dst, u32 dlen);
 int smb_compression_compress_chained(__le16 alg, bool allow_pattern,
                                     const void *src, u32 slen,
                                     void *dst, u32 *dlen);

diff --git a/fs/smb/server/compress.c b/fs/smb/server/compress.c
index 95e48fa6b4486b751d247863580a2546bb128d58..821299888ad3adfc062fbd6df8af99f3ca11fa3e 100644 (file)
--- a/fs/smb/server/compress.c
+++ b/fs/smb/server/compress.c
@@ -69,6 +69,7 @@ int ksmbd_decompress_request(struct ksmbd_conn *conn)
        *(__be32 *)out = cpu_to_be32(out_size);
        rc = smb_compression_decompress(conn->compress_algorithm,
                                        conn->compress_chained,
+                                       conn->compress_pattern,
                                        buf, pdu_size, out + 4, out_size);
        if (rc) {
                kvfree(out);