lzma: Port size-checking ulzman() version to coreboot
We've had a second version of ulzma() that would check the input and
output buffer sizes in libpayload for a while now. Since it's generally
never a bad idea to double-check for overruns, let's port it to coreboot
and use it where applicable. (This requires a small fix in the four byte
at a time read optimization we only have in coreboot, since it made the
stream counter hit the end a little earlier than the algorithm liked and
could trigger an assertion.)
BRANCH=None
BUG=None
TEST=Booted Oak, Jerry and Falco.
Change-Id: Id566b31dfa896ea1b991badf5a6ad9d075aef987
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/13637
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/src/lib/lzma.c b/src/lib/lzma.c
index c04f4a4..5566cd5 100644
--- a/src/lib/lzma.c
+++ b/src/lib/lzma.c
@@ -16,9 +16,10 @@
#include "lzmadecode.h"
-unsigned long ulzma(unsigned char * src, unsigned char * dst)
+size_t ulzman(const void *src, size_t srcn, void *dst, size_t dstn)
{
unsigned char properties[LZMA_PROPERTIES_SIZE];
+ const int data_offset = LZMA_PROPERTIES_SIZE + 8;
UInt32 outSize;
SizeT inProcessed;
SizeT outProcessed;
@@ -26,7 +27,7 @@
CLzmaDecoderState state;
SizeT mallocneeds;
MAYBE_STATIC unsigned char scratchpad[15980];
- unsigned char *cp;
+ const unsigned char *cp;
/* Note: these timestamps aren't useful for memory-mapped media (x86) */
timestamp_add_now(TS_START_ULZMA);
@@ -37,7 +38,8 @@
* byte and re-construct. */
cp = src + LZMA_PROPERTIES_SIZE;
outSize = cp[3] << 24 | cp[2] << 16 | cp[1] << 8 | cp[0];
- if (LzmaDecodeProperties(&state.Properties, properties, LZMA_PROPERTIES_SIZE) != LZMA_RESULT_OK) {
+ if (LzmaDecodeProperties(&state.Properties, properties,
+ LZMA_PROPERTIES_SIZE) != LZMA_RESULT_OK) {
printk(BIOS_WARNING, "lzma: Incorrect stream properties.\n");
return 0;
}
@@ -47,8 +49,8 @@
return 0;
}
state.Probs = (CProb *)scratchpad;
- res = LzmaDecode(&state, src + LZMA_PROPERTIES_SIZE + 8, (SizeT)0xffffffff, &inProcessed,
- dst, outSize, &outProcessed);
+ res = LzmaDecode(&state, src + data_offset, srcn - data_offset,
+ &inProcessed, dst, outSize, &outProcessed);
if (res != 0) {
printk(BIOS_WARNING, "lzma: Decoding error = %d\n", res);
return 0;
@@ -56,3 +58,8 @@
timestamp_add_now(TS_END_ULZMA);
return outProcessed;
}
+
+size_t ulzma(const void *src, void *dst)
+{
+ return ulzman(src, ~(size_t)0, dst, ~(size_t)0);
+}
diff --git a/src/lib/lzmadecode.c b/src/lib/lzmadecode.c
index ada7226..fbf1596 100644
--- a/src/lib/lzmadecode.c
+++ b/src/lib/lzmadecode.c
@@ -29,9 +29,12 @@
#define kBitModelTotal (1 << kNumBitModelTotalBits)
#define kNumMoveBits 5
-/* Use 32-bit reads whenever possible to avoid bad flash performance. */
+/* Use 32-bit reads whenever possible to avoid bad flash performance. Fall back
+ * to byte reads for last 4 bytes since RC_TEST returns an error when BufferLim
+ * is *reached* (not surpassed!), meaning we can't allow that to happen while
+ * there are still bytes to decode from the algorithm's point of view. */
#define RC_READ_BYTE (look_ahead_ptr < 4 ? look_ahead.raw[look_ahead_ptr++] \
- : ((((uintptr_t) Buffer & 3) || ((SizeT) (BufferLim - Buffer) < 4)) ? (*Buffer++) \
+ : ((((uintptr_t) Buffer & 3) || ((SizeT) (BufferLim - Buffer) <= 4)) ? (*Buffer++) \
: ((look_ahead.dw = *(UInt32 *)Buffer), (Buffer += 4), (look_ahead_ptr = 1), look_ahead.raw[0])))
#define RC_INIT2 Code = 0; Range = 0xFFFFFFFF; \
diff --git a/src/lib/rmodule.c b/src/lib/rmodule.c
index 13eb324a..628195c 100644
--- a/src/lib/rmodule.c
+++ b/src/lib/rmodule.c
@@ -295,7 +295,7 @@
if (map == NULL)
return -1;
- fsize = ulzma(map, rmod_loc);
+ fsize = ulzman(map, stage.len, rmod_loc, stage.memlen);
rdev_munmap(fh, map);
diff --git a/src/lib/selfboot.c b/src/lib/selfboot.c
index 60cda6a..6d86159 100644
--- a/src/lib/selfboot.c
+++ b/src/lib/selfboot.c
@@ -378,12 +378,12 @@
/* Copy data from the initial buffer */
if (ptr->s_filesz) {
unsigned char *middle, *end;
- size_t len;
- len = ptr->s_filesz;
+ size_t len = ptr->s_filesz;
+ size_t memsz = ptr->s_memsz;
switch(ptr->compression) {
case CBFS_COMPRESS_LZMA: {
printk(BIOS_DEBUG, "using LZMA\n");
- len = ulzma(src, dest);
+ len = ulzman(src, len, dest, memsz);
if (!len) /* Decompression Error. */
return 0;
break;
@@ -397,7 +397,7 @@
printk(BIOS_INFO, "CBFS: Unknown compression type %d\n", ptr->compression);
return -1;
}
- end = dest + ptr->s_memsz;
+ end = dest + memsz;
middle = dest + len;
printk(BIOS_SPEW, "[ 0x%08lx, %08lx, 0x%08lx) <- %08lx\n",
(unsigned long)dest,