lzma/gzip: fix potential oops when input data is truncated
If the lzma/gzip decompressors are called with insufficient input data
(len > 0 & fill = NULL), they will attempt to call the fill function to
obtain more data, leading to a kernel oops.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/decompress_unlzma.c b/lib/decompress_unlzma.c
index 0b954e0..ca82fde 100644
--- a/lib/decompress_unlzma.c
+++ b/lib/decompress_unlzma.c
@@ -82,6 +82,11 @@
#define RC_MODEL_TOTAL_BITS 11
+static int nofill(void *buffer, unsigned int len)
+{
+ return -1;
+}
+
/* Called twice: once at startup and once in rc_normalize() */
static void INIT rc_read(struct rc *rc)
{
@@ -97,7 +102,10 @@
int (*fill)(void*, unsigned int),
char *buffer, int buffer_size)
{
- rc->fill = fill;
+ if (fill)
+ rc->fill = fill;
+ else
+ rc->fill = nofill;
rc->buffer = (uint8_t *)buffer;
rc->buffer_size = buffer_size;
rc->buffer_end = rc->buffer + rc->buffer_size;