From d5caac8ab79d068ad9a41030c772d03a4d4fbd7b Mon Sep 17 00:00:00 2001 From: Daniel Axtens Date: Mon, 28 Jun 2021 14:16:14 +1000 Subject: [PATCH 5/8] video/readers/jpeg: 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 Reviewed-by: Daniel Kiper --- grub-core/video/readers/jpeg.c | 86 +++++++++++++++++++++++++++------- 1 file changed, 70 insertions(+), 16 deletions(-) diff --git a/grub-core/video/readers/jpeg.c b/grub-core/video/readers/jpeg.c index c47ffd651..806c56c78 100644 --- a/grub-core/video/readers/jpeg.c +++ b/grub-core/video/readers/jpeg.c @@ -109,9 +109,17 @@ static grub_uint8_t grub_jpeg_get_byte (struct grub_jpeg_data *data) { grub_uint8_t r; + grub_ssize_t bytes_read; 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, + "jpeg: unexpected end of data"); + return 0; + } return r; } @@ -120,9 +128,17 @@ static grub_uint16_t grub_jpeg_get_word (struct grub_jpeg_data *data) { grub_uint16_t r; + grub_ssize_t bytes_read; r = 0; - grub_file_read (data->file, &r, sizeof (grub_uint16_t)); + bytes_read = grub_file_read (data->file, &r, sizeof (grub_uint16_t)); + + if (bytes_read != sizeof (grub_uint16_t)) + { + grub_error (GRUB_ERR_BAD_FILE_TYPE, + "jpeg: unexpected end of data"); + return 0; + } return grub_be_to_cpu16 (r); } @@ -135,6 +151,11 @@ grub_jpeg_get_bit (struct grub_jpeg_data *data) if (data->bit_mask == 0) { data->bit_save = grub_jpeg_get_byte (data); + if (grub_errno != GRUB_ERR_NONE) { + grub_error (GRUB_ERR_BAD_FILE_TYPE, + "jpeg: file read error"); + return 0; + } if (data->bit_save == JPEG_ESC_CHAR) { if (grub_jpeg_get_byte (data) != 0) @@ -143,6 +164,11 @@ grub_jpeg_get_bit (struct grub_jpeg_data *data) "jpeg: invalid 0xFF in data stream"); return 0; } + if (grub_errno != GRUB_ERR_NONE) + { + grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: file read error"); + return 0; + } } data->bit_mask = 0x80; } @@ -161,7 +187,7 @@ grub_jpeg_get_number (struct grub_jpeg_data *data, int num) return 0; msb = value = grub_jpeg_get_bit (data); - for (i = 1; i < num; i++) + for (i = 1; i < num && grub_errno == GRUB_ERR_NONE; i++) value = (value << 1) + (grub_jpeg_get_bit (data) != 0); if (!msb) value += 1 - (1 << num); @@ -208,6 +234,8 @@ grub_jpeg_decode_huff_table (struct grub_jpeg_data *data) while (data->file->offset + sizeof (count) + 1 <= next_marker) { id = grub_jpeg_get_byte (data); + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; ac = (id >> 4) & 1; id &= 0xF; if (id > 1) @@ -258,6 +286,8 @@ grub_jpeg_decode_quan_table (struct grub_jpeg_data *data) next_marker = data->file->offset; next_marker += grub_jpeg_get_word (data); + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; if (next_marker > data->file->size) { @@ -269,6 +299,8 @@ grub_jpeg_decode_quan_table (struct grub_jpeg_data *data) <= next_marker) { id = grub_jpeg_get_byte (data); + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; if (id >= 0x10) /* Upper 4-bit is precision. */ return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: only 8-bit precision is supported"); @@ -300,6 +332,9 @@ grub_jpeg_decode_sof (struct grub_jpeg_data *data) next_marker = data->file->offset; next_marker += grub_jpeg_get_word (data); + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; + if (grub_jpeg_get_byte (data) != 8) return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: only 8-bit precision is supported"); @@ -325,6 +360,8 @@ grub_jpeg_decode_sof (struct grub_jpeg_data *data) return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid index"); ss = grub_jpeg_get_byte (data); /* Sampling factor. */ + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; if (!id) { grub_uint8_t vs, hs; @@ -504,7 +541,7 @@ grub_jpeg_idct_transform (jpeg_data_unit_t du) } } -static void +static grub_err_t grub_jpeg_decode_du (struct grub_jpeg_data *data, int id, jpeg_data_unit_t du) { int h1, h2, qt; @@ -519,6 +556,9 @@ grub_jpeg_decode_du (struct grub_jpeg_data *data, int id, jpeg_data_unit_t du) data->dc_value[id] += grub_jpeg_get_number (data, grub_jpeg_get_huff_code (data, h1)); + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; + du[0] = data->dc_value[id] * (int) data->quan_table[qt][0]; pos = 1; while (pos < ARRAY_SIZE (data->quan_table[qt])) @@ -533,11 +573,13 @@ grub_jpeg_decode_du (struct grub_jpeg_data *data, int id, jpeg_data_unit_t du) num >>= 4; pos += num; + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; + if (pos >= ARRAY_SIZE (jpeg_zigzag_order)) { - grub_error (GRUB_ERR_BAD_FILE_TYPE, - "jpeg: invalid position in zigzag order!?"); - return; + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "jpeg: invalid position in zigzag order!?"); } du[jpeg_zigzag_order[pos]] = val * (int) data->quan_table[qt][pos]; @@ -545,6 +587,7 @@ grub_jpeg_decode_du (struct grub_jpeg_data *data, int id, jpeg_data_unit_t du) } grub_jpeg_idct_transform (du); + return GRUB_ERR_NONE; } static void @@ -603,7 +646,8 @@ grub_jpeg_decode_sos (struct grub_jpeg_data *data) data_offset += grub_jpeg_get_word (data); cc = grub_jpeg_get_byte (data); - + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; if (cc != 3 && cc != 1) return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: component count must be 1 or 3"); @@ -616,7 +660,8 @@ grub_jpeg_decode_sos (struct grub_jpeg_data *data) id = grub_jpeg_get_byte (data) - 1; if ((id < 0) || (id >= 3)) return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid index"); - + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; ht = grub_jpeg_get_byte (data); data->comp_index[id][1] = (ht >> 4); data->comp_index[id][2] = (ht & 0xF) + 2; @@ -624,11 +669,14 @@ grub_jpeg_decode_sos (struct grub_jpeg_data *data) if ((data->comp_index[id][1] < 0) || (data->comp_index[id][1] > 3) || (data->comp_index[id][2] < 0) || (data->comp_index[id][2] > 3)) return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid hufftable index"); + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; } grub_jpeg_get_byte (data); /* Skip 3 unused bytes. */ grub_jpeg_get_word (data); - + if (grub_errno != GRUB_ERR_NONE) + return grub_errno; if (data->file->offset != data_offset) return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: extra byte in sos"); @@ -646,6 +694,7 @@ grub_jpeg_decode_data (struct grub_jpeg_data *data) { unsigned c1, vb, hb, nr1, nc1; int rst = data->dri; + grub_err_t err = GRUB_ERR_NONE; vb = 8 << data->log_vs; hb = 8 << data->log_hs; @@ -666,17 +715,22 @@ grub_jpeg_decode_data (struct grub_jpeg_data *data) for (r2 = 0; r2 < (1U << data->log_vs); r2++) for (c2 = 0; c2 < (1U << data->log_hs); c2++) - grub_jpeg_decode_du (data, 0, data->ydu[r2 * 2 + c2]); + { + err = grub_jpeg_decode_du (data, 0, data->ydu[r2 * 2 + c2]); + if (err != GRUB_ERR_NONE) + return err; + } if (data->color_components >= 3) { - grub_jpeg_decode_du (data, 1, data->cbdu); - grub_jpeg_decode_du (data, 2, data->crdu); + err = grub_jpeg_decode_du (data, 1, data->cbdu); + if (err != GRUB_ERR_NONE) + return err; + err = grub_jpeg_decode_du (data, 2, data->crdu); + if (err != GRUB_ERR_NONE) + return err; } - if (grub_errno) - return grub_errno; - nr2 = (data->r1 == nr1 - 1) ? (data->image_height - data->r1 * vb) : vb; nc2 = (c1 == nc1 - 1) ? (data->image_width - c1 * hb) : hb; -- 2.33.5