From 92faa8b109180fa28ec899479f676e62a3a391b7 Mon Sep 17 00:00:00 2001 From: Anatolij Gustschin Date: Sat, 15 Oct 2011 06:32:52 +0000 Subject: zlib: handle overflow while calculating available stream input size If compressed data is located in sectors at the end of the flash and it's offset + input stream size > 0xFFFFFFFF, the uncompressing time is very long, since processing of the stream is done bytewise (and not blockwise) due to overflow in inflate_fast() while calculation and checking for enough input available. Check for this overflow condition and limit the available stream input size to the actually max. possible input size. This fixes the problem. The issue is easily reproduceable by placing a gziped bitmap in flash, e.g. at FFF80000, and running 'bmp' commands like 'bmp info FFF80000' or 'bmp display FFF80000'. The uncompressing can take up to 3 sec. whereas it should normaly take a fraction of a second. If the 'splashimage' environment variable points to this address, the booting time also increases significantly. Signed-off-by: Anatolij Gustschin --- lib/zlib/inffast.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'lib/zlib') diff --git a/lib/zlib/inffast.c b/lib/zlib/inffast.c index 8e823df4cf..4834b0c86e 100644 --- a/lib/zlib/inffast.c +++ b/lib/zlib/inffast.c @@ -100,6 +100,14 @@ unsigned start; /* inflate()'s starting value for strm->avail_out */ state = (struct inflate_state FAR *)strm->state; in = strm->next_in - OFF; last = in + (strm->avail_in - 5); + if (in > last && strm->avail_in > 5) { + /* + * overflow detected, limit strm->avail_in to the + * max. possible size and recalculate last + */ + strm->avail_in = 0xffffffff - (unsigned int)in; + last = in + (strm->avail_in - 5); + } out = strm->next_out - OFF; beg = out - (start - strm->avail_out); end = out + (strm->avail_out - 257); -- cgit v1.2.1