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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-07-03 16:06:57 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-07-03 16:12:04 -0700
commit4a3a99045177369700c60d074c0e525e8093b0fc (patch)
treeccadaf9779f3f84f843c971bba5fe45383be049d
parentecca47ce8294843045e7465d76fee84dbf07a004 (diff)
downloadlinux-stericsson-4a3a99045177369700c60d074c0e525e8093b0fc.tar.gz
lz4: add overrun checks to lz4_uncompress_unknownoutputsize()
Jan points out that I forgot to make the needed fixes to the lz4_uncompress_unknownoutputsize() function to mirror the changes done in lz4_decompress() with regards to potential pointer overflows. The only in-kernel user of this function is the zram code, which only takes data from a valid compressed buffer that it made itself, so it's not a big issue. But due to external kernel modules using this function, it's better to be safe here. Reported-by: Jan Beulich <JBeulich@suse.com> Cc: "Don A. Bailey" <donb@securitymouse.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--lib/lz4/lz4_decompress.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/lib/lz4/lz4_decompress.c b/lib/lz4/lz4_decompress.c
index b74da447e81e..7a85967060a5 100644
--- a/lib/lz4/lz4_decompress.c
+++ b/lib/lz4/lz4_decompress.c
@@ -192,6 +192,8 @@ static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,
int s = 255;
while ((ip < iend) && (s == 255)) {
s = *ip++;
+ if (unlikely(length > (size_t)(length + s)))
+ goto _output_error;
length += s;
}
}
@@ -232,6 +234,8 @@ static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,
if (length == ML_MASK) {
while (ip < iend) {
int s = *ip++;
+ if (unlikely(length > (size_t)(length + s)))
+ goto _output_error;
length += s;
if (s == 255)
continue;
@@ -284,7 +288,7 @@ static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,
/* write overflow error detected */
_output_error:
- return (int) (-(((char *) ip) - source));
+ return -1;
}
int lz4_decompress(const unsigned char *src, size_t *src_len,