diff options
Diffstat (limited to 'debian/patches/0068-video-readers-png-Abort-sooner-if-a-read-operation-f.patch')
-rw-r--r-- | debian/patches/0068-video-readers-png-Abort-sooner-if-a-read-operation-f.patch | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/debian/patches/0068-video-readers-png-Abort-sooner-if-a-read-operation-f.patch b/debian/patches/0068-video-readers-png-Abort-sooner-if-a-read-operation-f.patch new file mode 100644 index 0000000..58e6e50 --- /dev/null +++ b/debian/patches/0068-video-readers-png-Abort-sooner-if-a-read-operation-f.patch @@ -0,0 +1,197 @@ +From 907f100c841f39e37e4801f726f6b47c2aa9191f Mon Sep 17 00:00:00 2001 +From: Daniel Axtens <dja@axtens.net> +Date: Tue, 6 Jul 2021 14:02:55 +1000 +Subject: video/readers/png: Abort sooner if a read operation fails + +Fuzzing revealed some inputs that were taking a long time, potentially +forever, because they did not bail quickly upon encountering an I/O error. + +Try to catch I/O errors sooner and bail out. + +Signed-off-by: Daniel Axtens <dja@axtens.net> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> +--- + grub-core/video/readers/png.c | 55 ++++++++++++++++++++++++++++++----- + 1 file changed, 47 insertions(+), 8 deletions(-) + +diff --git a/grub-core/video/readers/png.c b/grub-core/video/readers/png.c +index 0157ff742..e2a6b1cf3 100644 +--- a/grub-core/video/readers/png.c ++++ b/grub-core/video/readers/png.c +@@ -142,6 +142,7 @@ static grub_uint8_t + grub_png_get_byte (struct grub_png_data *data) + { + grub_uint8_t r; ++ grub_ssize_t bytes_read = 0; + + if ((data->inside_idat) && (data->idat_remain == 0)) + { +@@ -175,7 +176,14 @@ grub_png_get_byte (struct grub_png_data *data) + } + + r = 0; +- grub_file_read (data->file, &r, 1); ++ bytes_read = grub_file_read (data->file, &r, 1); ++ ++ if (bytes_read != 1) ++ { ++ grub_error (GRUB_ERR_BAD_FILE_TYPE, ++ "png: unexpected end of data"); ++ return 0; ++ } + + if (data->inside_idat) + data->idat_remain--; +@@ -231,15 +239,16 @@ grub_png_decode_image_palette (struct grub_png_data *data, + if (len == 0) + return GRUB_ERR_NONE; + +- for (i = 0; 3 * i < len && i < 256; i++) ++ grub_errno = GRUB_ERR_NONE; ++ for (i = 0; 3 * i < len && i < 256 && grub_errno == GRUB_ERR_NONE; i++) + for (j = 0; j < 3; j++) + data->palette[i][j] = grub_png_get_byte (data); +- for (i *= 3; i < len; i++) ++ for (i *= 3; i < len && grub_errno == GRUB_ERR_NONE; i++) + grub_png_get_byte (data); + + grub_png_get_dword (data); + +- return GRUB_ERR_NONE; ++ return grub_errno; + } + + static grub_err_t +@@ -256,9 +265,13 @@ grub_png_decode_image_header (struct grub_png_data *data) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, "png: invalid image size"); + + color_bits = grub_png_get_byte (data); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + data->is_16bit = (color_bits == 16); + + color_type = grub_png_get_byte (data); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + + /* According to PNG spec, no other types are valid. */ + if ((color_type & ~(PNG_COLOR_MASK_ALPHA | PNG_COLOR_MASK_COLOR)) +@@ -340,14 +353,20 @@ grub_png_decode_image_header (struct grub_png_data *data) + if (grub_png_get_byte (data) != PNG_COMPRESSION_BASE) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: compression method not supported"); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + + if (grub_png_get_byte (data) != PNG_FILTER_TYPE_BASE) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: filter method not supported"); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + + if (grub_png_get_byte (data) != PNG_INTERLACE_NONE) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: interlace method not supported"); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + + /* Skip crc checksum. */ + grub_png_get_dword (data); +@@ -449,7 +468,7 @@ grub_png_get_huff_code (struct grub_png_data *data, struct huff_table *ht) + int code, i; + + code = 0; +- for (i = 0; i < ht->max_length; i++) ++ for (i = 0; i < ht->max_length && grub_errno == GRUB_ERR_NONE; i++) + { + code = (code << 1) + grub_png_get_bits (data, 1); + if (code < ht->maxval[i]) +@@ -504,8 +523,14 @@ grub_png_init_dynamic_block (struct grub_png_data *data) + grub_uint8_t lens[DEFLATE_HCLEN_MAX]; + + nl = DEFLATE_HLIT_BASE + grub_png_get_bits (data, 5); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + nd = DEFLATE_HDIST_BASE + grub_png_get_bits (data, 5); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + nb = DEFLATE_HCLEN_BASE + grub_png_get_bits (data, 4); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + + if ((nl > DEFLATE_HLIT_MAX) || (nd > DEFLATE_HDIST_MAX) || + (nb > DEFLATE_HCLEN_MAX)) +@@ -533,7 +558,7 @@ grub_png_init_dynamic_block (struct grub_png_data *data) + data->dist_offset); + + prev = 0; +- for (i = 0; i < nl + nd; i++) ++ for (i = 0; i < nl + nd && grub_errno == GRUB_ERR_NONE; i++) + { + int n, code; + struct huff_table *ht; +@@ -721,17 +746,21 @@ grub_png_read_dynamic_block (struct grub_png_data *data) + len = cplens[n]; + if (cplext[n]) + len += grub_png_get_bits (data, cplext[n]); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + + n = grub_png_get_huff_code (data, &data->dist_table); + dist = cpdist[n]; + if (cpdext[n]) + dist += grub_png_get_bits (data, cpdext[n]); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + + pos = data->wp - dist; + if (pos < 0) + pos += WSIZE; + +- while (len > 0) ++ while (len > 0 && grub_errno == GRUB_ERR_NONE) + { + data->slide[data->wp] = data->slide[pos]; + grub_png_output_byte (data, data->slide[data->wp]); +@@ -759,7 +788,11 @@ grub_png_decode_image_data (struct grub_png_data *data) + int final; + + cmf = grub_png_get_byte (data); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + flg = grub_png_get_byte (data); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + + if ((cmf & 0xF) != Z_DEFLATED) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, +@@ -774,7 +807,11 @@ grub_png_decode_image_data (struct grub_png_data *data) + int block_type; + + final = grub_png_get_bits (data, 1); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + block_type = grub_png_get_bits (data, 2); ++ if (grub_errno != GRUB_ERR_NONE) ++ return grub_errno; + + switch (block_type) + { +@@ -790,7 +827,7 @@ grub_png_decode_image_data (struct grub_png_data *data) + grub_png_get_byte (data); + grub_png_get_byte (data); + +- for (i = 0; i < len; i++) ++ for (i = 0; i < len && grub_errno == GRUB_ERR_NONE; i++) + grub_png_output_byte (data, grub_png_get_byte (data)); + + break; +@@ -1045,6 +1082,8 @@ grub_png_decode_png (struct grub_png_data *data) + + len = grub_png_get_dword (data); + type = grub_png_get_dword (data); ++ if (grub_errno != GRUB_ERR_NONE) ++ break; + data->next_offset = data->file->offset + len + 4; + + switch (type) |