X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fdecompress_unlzo.c;h=26f89ad03304c290785c697bfb481c289d4eed81;hb=HEAD;hp=bcb3a4bd68ff92b22811254e8335a8c67f1abc7c;hpb=c1518f12bab97a6d409a25aaccb02dc8895800f3;p=pandora-kernel.git

diff --git a/lib/decompress_unlzo.c b/lib/decompress_unlzo.c
index bcb3a4bd68ff..26f89ad03304 100644
--- a/lib/decompress_unlzo.c
+++ b/lib/decompress_unlzo.c
@@ -31,9 +31,8 @@
  */
 
 #ifdef STATIC
-#include "lzo/lzo1x_decompress.c"
+#include "lzo/lzo1x_decompress_safe.c"
 #else
-#include <linux/slab.h>
 #include <linux/decompress/unlzo.h>
 #endif
 
@@ -49,14 +48,25 @@ static const unsigned char lzop_magic[] = {
 
 #define LZO_BLOCK_SIZE        (256*1024l)
 #define HEADER_HAS_FILTER      0x00000800L
+#define HEADER_SIZE_MIN       (9 + 7     + 4 + 8     + 1       + 4)
+#define HEADER_SIZE_MAX       (9 + 7 + 1 + 8 + 8 + 4 + 1 + 255 + 4)
 
-STATIC inline int INIT parse_header(u8 *input, u8 *skip)
+STATIC inline int INIT parse_header(u8 *input, int *skip, int in_len)
 {
 	int l;
 	u8 *parse = input;
+	u8 *end = input + in_len;
 	u8 level = 0;
 	u16 version;
 
+	/*
+	 * Check that there's enough input to possibly have a valid header.
+	 * Then it is possible to parse several fields until the minimum
+	 * size may have been used.
+	 */
+	if (in_len < HEADER_SIZE_MIN)
+		return 0;
+
 	/* read magic: 9 first bits */
 	for (l = 0; l < 9; l++) {
 		if (*parse++ != lzop_magic[l])
@@ -74,6 +84,15 @@ STATIC inline int INIT parse_header(u8 *input, u8 *skip)
 	else
 		parse += 4; /* flags */
 
+	/*
+	 * At least mode, mtime_low, filename length, and checksum must
+	 * be left to be parsed. If also mtime_high is present, it's OK
+	 * because the next input buffer check is after reading the
+	 * filename length.
+	 */
+	if (end - parse < 8 + 1 + 4)
+		return 0;
+
 	/* skip mode and mtime_low */
 	parse += 8;
 	if (version >= 0x0940)
@@ -81,6 +100,8 @@ STATIC inline int INIT parse_header(u8 *input, u8 *skip)
 
 	l = *parse++;
 	/* don't care about the file name, and skip checksum */
+	if (end - parse < l + 4)
+		return 0;
 	parse += l + 4;
 
 	*skip = parse - input;
@@ -91,16 +112,15 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
 				int (*fill) (void *, unsigned int),
 				int (*flush) (void *, unsigned int),
 				u8 *output, int *posp,
-				void (*error_fn) (char *x))
+				void (*error) (char *x))
 {
-	u8 skip = 0, r = 0;
+	u8 r = 0;
+	int skip = 0;
 	u32 src_len, dst_len;
 	size_t tmp;
 	u8 *in_buf, *in_buf_save, *out_buf;
 	int ret = -1;
 
-	set_error_fn(error_fn);
-
 	if (output) {
 		out_buf = output;
 	} else if (!flush) {
@@ -119,8 +139,8 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
 		goto exit_1;
 	} else if (input) {
 		in_buf = input;
-	} else if (!fill || !posp) {
-		error("NULL input pointer and missing position pointer or fill function");
+	} else if (!fill) {
+		error("NULL input pointer and missing fill function");
 		goto exit_1;
 	} else {
 		in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE));
@@ -134,22 +154,47 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
 	if (posp)
 		*posp = 0;
 
-	if (fill)
-		fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));
+	if (fill) {
+		/*
+		 * Start from in_buf + HEADER_SIZE_MAX to make it possible
+		 * to use memcpy() to copy the unused data to the beginning
+		 * of the buffer. This way memmove() isn't needed which
+		 * is missing from pre-boot environments of most archs.
+		 */
+		in_buf += HEADER_SIZE_MAX;
+		in_len = fill(in_buf, HEADER_SIZE_MAX);
+	}
 
-	if (!parse_header(input, &skip)) {
+	if (!parse_header(in_buf, &skip, in_len)) {
 		error("invalid header");
 		goto exit_2;
 	}
 	in_buf += skip;
+	in_len -= skip;
+
+	if (fill) {
+		/* Move the unused data to the beginning of the buffer. */
+		memcpy(in_buf_save, in_buf, in_len);
+		in_buf = in_buf_save;
+	}
 
 	if (posp)
 		*posp = skip;
 
 	for (;;) {
 		/* read uncompressed block size */
+		if (fill && in_len < 4) {
+			skip = fill(in_buf + in_len, 4 - in_len);
+			if (skip > 0)
+				in_len += skip;
+		}
+		if (in_len < 4) {
+			error("file corrupted");
+			goto exit_2;
+		}
 		dst_len = get_unaligned_be32(in_buf);
 		in_buf += 4;
+		in_len -= 4;
 
 		/* exit if last block */
 		if (dst_len == 0) {
@@ -164,8 +209,18 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
 		}
 
 		/* read compressed block size, and skip block checksum info */
+		if (fill && in_len < 8) {
+			skip = fill(in_buf + in_len, 8 - in_len);
+			if (skip > 0)
+				in_len += skip;
+		}
+		if (in_len < 8) {
+			error("file corrupted");
+			goto exit_2;
+		}
 		src_len = get_unaligned_be32(in_buf);
 		in_buf += 8;
+		in_len -= 8;
 
 		if (src_len <= 0 || src_len > dst_len) {
 			error("file corrupted");
@@ -173,6 +228,15 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
 		}
 
 		/* decompress */
+		if (fill && in_len < src_len) {
+			skip = fill(in_buf + in_len, src_len - in_len);
+			if (skip > 0)
+				in_len += skip;
+		}
+		if (in_len < src_len) {
+			error("file corrupted");
+			goto exit_2;
+		}
 		tmp = dst_len;
 
 		/* When the input data is not compressed at all,
@@ -190,17 +254,26 @@ STATIC inline int INIT unlzo(u8 *input, int in_len,
 			}
 		}
 
-		if (flush)
-			flush(out_buf, dst_len);
+		if (flush && flush(out_buf, dst_len) != dst_len)
+			goto exit_2;
 		if (output)
 			out_buf += dst_len;
 		if (posp)
 			*posp += src_len + 12;
+
+		in_buf += src_len;
+		in_len -= src_len;
 		if (fill) {
+			/*
+			 * If there happens to still be unused data left in
+			 * in_buf, move it to the beginning of the buffer.
+			 * Use a loop to avoid memmove() dependency.
+			 */
+			if (in_len > 0)
+				for (skip = 0; skip < in_len; ++skip)
+					in_buf_save[skip] = in_buf[skip];
 			in_buf = in_buf_save;
-			fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));
-		} else
-			in_buf += src_len;
+		}
 	}
 
 	ret = 0;