From 4148c1f67abf823099b2d7db6851e4aea407f5ee Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 24 Jun 2014 16:59:01 -0400 Subject: [PATCH] lz4: fix another possible overrun There is one other possible overrun in the lz4 code as implemented by Linux at this point in time (which differs from the upstream lz4 codebase, but will get synced at in a future kernel release.) As pointed out by Don, we also need to check the overflow in the data itself. While we are at it, replace the odd error return value with just a "simple" -1 value as the return value is never used for anything other than a basic "did this work or not" check. Reported-by: "Don A. Bailey" Reported-by: Willy Tarreau Cc: stable Signed-off-by: Greg Kroah-Hartman --- lib/lz4/lz4_decompress.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/lz4/lz4_decompress.c b/lib/lz4/lz4_decompress.c index 99a03acb7d47..b74da447e81e 100644 --- a/lib/lz4/lz4_decompress.c +++ b/lib/lz4/lz4_decompress.c @@ -108,6 +108,8 @@ static int lz4_uncompress(const char *source, char *dest, int osize) if (length == ML_MASK) { for (; *ip == 255; length += 255) ip++; + if (unlikely(length > (size_t)(length + *ip))) + goto _output_error; length += *ip++; } @@ -157,7 +159,7 @@ static int lz4_uncompress(const char *source, char *dest, int osize) /* write overflow error detected */ _output_error: - return (int) (-(((char *)ip) - source)); + return -1; } static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,