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ffmpeg.wasm-core
Commit 0a467a9b authored by Justin Ruggles's avatar Justin Ruggles
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tiffdec: use bytestream2 to simplify overread/overwrite protection 

Based on a patch by Paul B Mahol <onemda@gmail.com>

CC:libav-stable@libav.org
parent 5748faf2
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Showing with 111 additions and 138 deletions
libavcodec/tiff.c
View file @ 0a467a9b
...@@ -34,6 +34,7 @@ ...@@ -34,6 +34,7 @@
#include "libavutil/intreadwrite.h" #include "libavutil/intreadwrite.h"
#include "libavutil/imgutils.h" #include "libavutil/imgutils.h"
#include "avcodec.h" #include "avcodec.h"
#include "bytestream.h"
#include "faxcompr.h" #include "faxcompr.h"
#include "internal.h" #include "internal.h"
#include "lzw.h" #include "lzw.h"
...@@ -42,6 +43,7 @@ ...@@ -42,6 +43,7 @@
typedef struct TiffContext { typedef struct TiffContext {
AVCodecContext *avctx; AVCodecContext *avctx;
GetByteContext gb;
int width, height; int width, height;
unsigned int bpp, bppcount; unsigned int bpp, bppcount;
...@@ -56,37 +58,27 @@ typedef struct TiffContext { ...@@ -56,37 +58,27 @@ typedef struct TiffContext {
int strips, rps, sstype; int strips, rps, sstype;
int sot; int sot;
const uint8_t *stripdata; int stripsizesoff, stripsize, stripoff, strippos;
const uint8_t *stripsizes;
int stripsize, stripoff;
LZWState *lzw; LZWState *lzw;
} TiffContext; } TiffContext;
static unsigned tget_short(const uint8_t **p, int le) static unsigned tget_short(GetByteContext *gb, int le)
{ {
unsigned v = le ? AV_RL16(*p) : AV_RB16(*p); return le ? bytestream2_get_le16(gb) : bytestream2_get_be16(gb);
*p += 2;
return v;
} }
static unsigned tget_long(const uint8_t **p, int le) static unsigned tget_long(GetByteContext *gb, int le)
{ {
unsigned v = le ? AV_RL32(*p) : AV_RB32(*p); return le ? bytestream2_get_le32(gb) : bytestream2_get_be32(gb);
*p += 4;
return v;
} }
static unsigned tget(const uint8_t **p, int type, int le) static unsigned tget(GetByteContext *gb, int type, int le)
{ {
switch (type) { switch (type) {
case TIFF_BYTE: case TIFF_BYTE: return bytestream2_get_byte(gb);
return *(*p)++; case TIFF_SHORT: return tget_short(gb, le);
case TIFF_SHORT: case TIFF_LONG: return tget_long(gb, le);
return tget_short(p, le); default: return UINT_MAX;
case TIFF_LONG:
return tget_long(p, le);
default:
return UINT_MAX;
} }
} }
...@@ -176,9 +168,9 @@ static int tiff_unpack_fax(TiffContext *s, uint8_t *dst, int stride, ...@@ -176,9 +168,9 @@ static int tiff_unpack_fax(TiffContext *s, uint8_t *dst, int stride,
static int tiff_unpack_strip(TiffContext *s, uint8_t *dst, int stride, static int tiff_unpack_strip(TiffContext *s, uint8_t *dst, int stride,
const uint8_t *src, int size, int lines) const uint8_t *src, int size, int lines)
{ {
PutByteContext pb;
int c, line, pixels, code, ret; int c, line, pixels, code, ret;
const uint8_t *ssrc = src; int width = ((s->width * s->bpp) + 7) >> 3;
int width = ((s->width * s->bpp) + 7) >> 3;
if (size <= 0) if (size <= 0)
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
...@@ -198,69 +190,56 @@ static int tiff_unpack_strip(TiffContext *s, uint8_t *dst, int stride, ...@@ -198,69 +190,56 @@ static int tiff_unpack_strip(TiffContext *s, uint8_t *dst, int stride,
av_log(s->avctx, AV_LOG_ERROR, "Error initializing LZW decoder\n"); av_log(s->avctx, AV_LOG_ERROR, "Error initializing LZW decoder\n");
return ret; return ret;
} }
for (line = 0; line < lines; line++) {
pixels = ff_lzw_decode(s->lzw, dst, width);
if (pixels < width) {
av_log(s->avctx, AV_LOG_ERROR, "Decoded only %i bytes of %i\n",
pixels, width);
return AVERROR_INVALIDDATA;
}
dst += stride;
}
return 0;
} }
if (s->compr == TIFF_CCITT_RLE || if (s->compr == TIFF_CCITT_RLE ||
s->compr == TIFF_G3 || s->compr == TIFF_G3 ||
s->compr == TIFF_G4) { s->compr == TIFF_G4) {
return tiff_unpack_fax(s, dst, stride, src, size, lines); return tiff_unpack_fax(s, dst, stride, src, size, lines);
} }
bytestream2_init(&s->gb, src, size);
bytestream2_init_writer(&pb, dst, stride * lines);
for (line = 0; line < lines; line++) { for (line = 0; line < lines; line++) {
if (src - ssrc > size) { if (bytestream2_get_bytes_left(&s->gb) == 0 || bytestream2_get_eof(&pb))
av_log(s->avctx, AV_LOG_ERROR, "Source data overread\n"); break;
return AVERROR_INVALIDDATA; bytestream2_seek_p(&pb, stride * line, SEEK_SET);
}
switch (s->compr) { switch (s->compr) {
case TIFF_RAW: case TIFF_RAW:
if (ssrc + size - src < width)
return AVERROR_INVALIDDATA;
if (!s->fill_order) { if (!s->fill_order) {
memcpy(dst, src, width); bytestream2_copy_buffer(&pb, &s->gb, width);
} else { } else {
int i; int i;
for (i = 0; i < width; i++) for (i = 0; i < width; i++)
dst[i] = ff_reverse[src[i]]; bytestream2_put_byte(&pb, ff_reverse[bytestream2_get_byte(&s->gb)]);
} }
src += width;
break; break;
case TIFF_PACKBITS: case TIFF_PACKBITS:
for (pixels = 0; pixels < width;) { for (pixels = 0; pixels < width;) {
if (ssrc + size - src < 2) code = ff_u8_to_s8(bytestream2_get_byte(&s->gb));
return AVERROR_INVALIDDATA;
code = (int8_t) *src++;
if (code >= 0) { if (code >= 0) {
code++; code++;
if (pixels + code > width || bytestream2_copy_buffer(&pb, &s->gb, code);
ssrc + size - src < code) {
av_log(s->avctx, AV_LOG_ERROR,
"Copy went out of bounds\n");
return AVERROR_INVALIDDATA;
}
memcpy(dst + pixels, src, code);
src += code;
pixels += code; pixels += code;
} else if (code != -128) { // -127..-1 } else if (code != -128) { // -127..-1
code = (-code) + 1; code = (-code) + 1;
if (pixels + code > width) { c = bytestream2_get_byte(&s->gb);
av_log(s->avctx, AV_LOG_ERROR, bytestream2_set_buffer(&pb, c, code);
"Run went out of bounds\n");
return AVERROR_INVALIDDATA;
}
c = *src++;
memset(dst + pixels, c, code);
pixels += code; pixels += code;
} }
} }
break; break;
case TIFF_LZW:
pixels = ff_lzw_decode(s->lzw, dst, width);
if (pixels < width) {
av_log(s->avctx, AV_LOG_ERROR, "Decoded only %i bytes of %i\n",
pixels, width);
return AVERROR_INVALIDDATA;
}
break;
} }
dst += stride;
} }
return 0; return 0;
} }
...@@ -317,20 +296,19 @@ static int init_image(TiffContext *s, AVFrame *frame) ...@@ -317,20 +296,19 @@ static int init_image(TiffContext *s, AVFrame *frame)
return 0; return 0;
} }
static int tiff_decode_tag(TiffContext *s, const uint8_t *start, static int tiff_decode_tag(TiffContext *s)
const uint8_t *buf, const uint8_t *end_buf)
{ {
unsigned tag, type, count, off, value = 0; unsigned tag, type, count, off, value = 0;
int i; int i, start;
uint32_t *pal; uint32_t *pal;
const uint8_t *rp, *gp, *bp;
if (end_buf - buf < 12) if (bytestream2_get_bytes_left(&s->gb) < 12)
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
tag = tget_short(&buf, s->le); tag = tget_short(&s->gb, s->le);
type = tget_short(&buf, s->le); type = tget_short(&s->gb, s->le);
count = tget_long(&buf, s->le); count = tget_long(&s->gb, s->le);
off = tget_long(&buf, s->le); off = tget_long(&s->gb, s->le);
start = bytestream2_tell(&s->gb);
if (type == 0 || type >= FF_ARRAY_ELEMS(type_sizes)) { if (type == 0 || type >= FF_ARRAY_ELEMS(type_sizes)) {
av_log(s->avctx, AV_LOG_DEBUG, "Unknown tiff type (%u) encountered\n", av_log(s->avctx, AV_LOG_DEBUG, "Unknown tiff type (%u) encountered\n",
...@@ -342,34 +320,26 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start, ...@@ -342,34 +320,26 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start,
switch (type) { switch (type) {
case TIFF_BYTE: case TIFF_BYTE:
case TIFF_SHORT: case TIFF_SHORT:
buf -= 4; bytestream2_seek(&s->gb, -4, SEEK_CUR);
value = tget(&buf, type, s->le); value = tget(&s->gb, type, s->le);
buf = NULL;
break; break;
case TIFF_LONG: case TIFF_LONG:
value = off; value = off;
buf = NULL;
break; break;
case TIFF_STRING: case TIFF_STRING:
if (count <= 4) { if (count <= 4) {
buf -= 4; bytestream2_seek(&s->gb, -4, SEEK_CUR);
break; break;
} }
default: default:
value = UINT_MAX; value = UINT_MAX;
buf = start + off; bytestream2_seek(&s->gb, off, SEEK_SET);
} }
} else { } else {
if (count <= 4 && type_sizes[type] * count <= 4) if (count <= 4 && type_sizes[type] * count <= 4)
buf -= 4; bytestream2_seek(&s->gb, -4, SEEK_CUR);
else else
buf = start + off; bytestream2_seek(&s->gb, off, SEEK_SET);
}
if (buf && (buf < start || buf > end_buf)) {
av_log(s->avctx, AV_LOG_ERROR,
"Tag referencing position outside the image\n");
return AVERROR_INVALIDDATA;
} }
switch (tag) { switch (tag) {
...@@ -398,8 +368,8 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start, ...@@ -398,8 +368,8 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start,
case TIFF_SHORT: case TIFF_SHORT:
case TIFF_LONG: case TIFF_LONG:
s->bpp = 0; s->bpp = 0;
for (i = 0; i < count && buf < end_buf; i++) for (i = 0; i < count; i++)
s->bpp += tget(&buf, type, s->le); s->bpp += tget(&s->gb, type, s->le);
break; break;
default: default:
s->bpp = -1; s->bpp = -1;
...@@ -459,35 +429,25 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start, ...@@ -459,35 +429,25 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start,
break; break;
case TIFF_STRIP_OFFS: case TIFF_STRIP_OFFS:
if (count == 1) { if (count == 1) {
s->stripdata = NULL; s->strippos = 0;
s->stripoff = value; s->stripoff = value;
} else } else
s->stripdata = start + off; s->strippos = off;
s->strips = count; s->strips = count;
if (s->strips == 1) if (s->strips == 1)
s->rps = s->height; s->rps = s->height;
s->sot = type; s->sot = type;
if (s->stripdata > end_buf) {
av_log(s->avctx, AV_LOG_ERROR,
"Tag referencing position outside the image\n");
return AVERROR_INVALIDDATA;
}
break; break;
case TIFF_STRIP_SIZE: case TIFF_STRIP_SIZE:
if (count == 1) { if (count == 1) {
s->stripsizes = NULL; s->stripsizesoff = 0;
s->stripsize = value; s->stripsize = value;
s->strips = 1; s->strips = 1;
} else { } else {
s->stripsizes = start + off; s->stripsizesoff = off;
} }
s->strips = count; s->strips = count;
s->sstype = type; s->sstype = type;
if (s->stripsizes > end_buf) {
av_log(s->avctx, AV_LOG_ERROR,
"Tag referencing position outside the image\n");
return AVERROR_INVALIDDATA;
}
break; break;
case TIFF_PREDICTOR: case TIFF_PREDICTOR:
s->predictor = value; s->predictor = value;
...@@ -517,24 +477,27 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start, ...@@ -517,24 +477,27 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start,
} }
s->fill_order = value - 1; s->fill_order = value - 1;
break; break;
case TIFF_PAL: case TIFF_PAL: {
GetByteContext pal_gb[3];
pal = (uint32_t *) s->palette; pal = (uint32_t *) s->palette;
off = type_sizes[type]; off = type_sizes[type];
if (count / 3 > 256 || end_buf - buf < count / 3 * off * 3) if (count / 3 > 256 ||
bytestream2_get_bytes_left(&s->gb) < count / 3 * off * 3)
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
rp = buf; pal_gb[0] = pal_gb[1] = pal_gb[2] = s->gb;
gp = buf + count / 3 * off; bytestream2_skip(&pal_gb[1], count / 3 * off);
bp = buf + count / 3 * off * 2; bytestream2_skip(&pal_gb[2], count / 3 * off * 2);
off = (type_sizes[type] - 1) << 3; off = (type_sizes[type] - 1) << 3;
for (i = 0; i < count / 3; i++) { for (i = 0; i < count / 3; i++) {
uint32_t p = 0xFF000000; uint32_t p = 0xFF000000;
p |= (tget(&rp, type, s->le) >> off) << 16; p |= (tget(&pal_gb[0], type, s->le) >> off) << 16;
p |= (tget(&gp, type, s->le) >> off) << 8; p |= (tget(&pal_gb[1], type, s->le) >> off) << 8;
p |= tget(&bp, type, s->le) >> off; p |= tget(&pal_gb[2], type, s->le) >> off;
pal[i] = p; pal[i] = p;
} }
s->palette_is_set = 1; s->palette_is_set = 1;
break; break;
}
case TIFF_PLANAR: case TIFF_PLANAR:
if (value == 2) { if (value == 2) {
avpriv_report_missing_feature(s->avctx, "Planar format"); avpriv_report_missing_feature(s->avctx, "Planar format");
...@@ -557,28 +520,29 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start, ...@@ -557,28 +520,29 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start,
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
} }
} }
bytestream2_seek(&s->gb, start, SEEK_SET);
return 0; return 0;
} }
static int decode_frame(AVCodecContext *avctx, static int decode_frame(AVCodecContext *avctx,
void *data, int *got_frame, AVPacket *avpkt) void *data, int *got_frame, AVPacket *avpkt)
{ {
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
TiffContext *const s = avctx->priv_data; TiffContext *const s = avctx->priv_data;
AVFrame *const p = data; AVFrame *const p = data;
const uint8_t *orig_buf = buf, *end_buf = buf + buf_size;
unsigned off; unsigned off;
int id, le, ret; int id, le, ret;
int i, j, entries, stride; int i, j, entries, stride;
unsigned soff, ssize; unsigned soff, ssize;
uint8_t *dst; uint8_t *dst;
GetByteContext stripsizes;
GetByteContext stripdata;
bytestream2_init(&s->gb, avpkt->data, avpkt->size);
// parse image header // parse image header
if (end_buf - buf < 8) if (avpkt->size < 8)
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
id = AV_RL16(buf); id = bytestream2_get_le16(&s->gb);
buf += 2;
if (id == 0x4949) if (id == 0x4949)
le = 1; le = 1;
else if (id == 0x4D4D) else if (id == 0x4D4D)
...@@ -593,27 +557,26 @@ static int decode_frame(AVCodecContext *avctx, ...@@ -593,27 +557,26 @@ static int decode_frame(AVCodecContext *avctx,
s->fill_order = 0; s->fill_order = 0;
// As TIFF 6.0 specification puts it "An arbitrary but carefully chosen number // As TIFF 6.0 specification puts it "An arbitrary but carefully chosen number
// that further identifies the file as a TIFF file" // that further identifies the file as a TIFF file"
if (tget_short(&buf, le) != 42) { if (tget_short(&s->gb, le) != 42) {
av_log(avctx, AV_LOG_ERROR, av_log(avctx, AV_LOG_ERROR,
"The answer to life, universe and everything is not correct!\n"); "The answer to life, universe and everything is not correct!\n");
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
} }
// Reset these pointers so we can tell if they were set this frame // Reset these offsets so we can tell if they were set this frame
s->stripsizes = s->stripdata = NULL; s->stripsizesoff = s->strippos = 0;
/* parse image file directory */ /* parse image file directory */
off = tget_long(&buf, le); off = tget_long(&s->gb, le);
if (off >= UINT_MAX - 14 || end_buf - orig_buf < off + 14) { if (off >= UINT_MAX - 14 || avpkt->size < off + 14) {
av_log(avctx, AV_LOG_ERROR, "IFD offset is greater than image size\n"); av_log(avctx, AV_LOG_ERROR, "IFD offset is greater than image size\n");
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
} }
buf = orig_buf + off; bytestream2_seek(&s->gb, off, SEEK_SET);
entries = tget_short(&buf, le); entries = tget_short(&s->gb, le);
for (i = 0; i < entries; i++) { for (i = 0; i < entries; i++) {
if ((ret = tiff_decode_tag(s, orig_buf, buf, end_buf)) < 0) if ((ret = tiff_decode_tag(s)) < 0)
return ret; return ret;
buf += 12;
} }
if (!s->stripdata && !s->stripoff) { if (!s->strippos && !s->stripoff) {
av_log(avctx, AV_LOG_ERROR, "Image data is missing\n"); av_log(avctx, AV_LOG_ERROR, "Image data is missing\n");
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
} }
...@@ -623,30 +586,40 @@ static int decode_frame(AVCodecContext *avctx, ...@@ -623,30 +586,40 @@ static int decode_frame(AVCodecContext *avctx,
if (s->strips == 1 && !s->stripsize) { if (s->strips == 1 && !s->stripsize) {
av_log(avctx, AV_LOG_WARNING, "Image data size missing\n"); av_log(avctx, AV_LOG_WARNING, "Image data size missing\n");
s->stripsize = buf_size - s->stripoff; s->stripsize = avpkt->size - s->stripoff;
} }
stride = p->linesize[0]; stride = p->linesize[0];
dst = p->data[0]; dst = p->data[0];
if (s->stripsizesoff) {
if (s->stripsizesoff >= avpkt->size)
return AVERROR_INVALIDDATA;
bytestream2_init(&stripsizes, avpkt->data + s->stripsizesoff,
avpkt->size - s->stripsizesoff);
}
if (s->strippos) {
if (s->strippos >= avpkt->size)
return AVERROR_INVALIDDATA;
bytestream2_init(&stripdata, avpkt->data + s->strippos,
avpkt->size - s->strippos);
}
for (i = 0; i < s->height; i += s->rps) { for (i = 0; i < s->height; i += s->rps) {
if (s->stripsizes) { if (s->stripsizesoff)
if (s->stripsizes >= end_buf) ssize = tget(&stripsizes, s->sstype, le);
return AVERROR_INVALIDDATA; else
ssize = tget(&s->stripsizes, s->sstype, s->le);
} else
ssize = s->stripsize; ssize = s->stripsize;
if (s->stripdata) { if (s->strippos)
if (s->stripdata >= end_buf) soff = tget(&stripdata, s->sot, le);
return AVERROR_INVALIDDATA; else
soff = tget(&s->stripdata, s->sot, s->le);
} else
soff = s->stripoff; soff = s->stripoff;
if (soff > buf_size || ssize > buf_size - soff) { if (soff > avpkt->size || ssize > avpkt->size - soff) {
av_log(avctx, AV_LOG_ERROR, "Invalid strip size/offset\n"); av_log(avctx, AV_LOG_ERROR, "Invalid strip size/offset\n");
return AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
} }
if ((ret = tiff_unpack_strip(s, dst, stride, orig_buf + soff, ssize, if ((ret = tiff_unpack_strip(s, dst, stride, avpkt->data + soff, ssize,
FFMIN(s->rps, s->height - i))) < 0) { FFMIN(s->rps, s->height - i))) < 0) {
if (avctx->err_recognition & AV_EF_EXPLODE) if (avctx->err_recognition & AV_EF_EXPLODE)
return ret; return ret;
...@@ -675,7 +648,7 @@ static int decode_frame(AVCodecContext *avctx, ...@@ -675,7 +648,7 @@ static int decode_frame(AVCodecContext *avctx,
} }
*got_frame = 1; *got_frame = 1;
return buf_size; return avpkt->size;
} }
static av_cold int tiff_init(AVCodecContext *avctx) static av_cold int tiff_init(AVCodecContext *avctx)
......
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