From 8bcd64423836bad3638684677f6d740bc7c9297f Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 28 Jan 2015 10:56:04 +0100 Subject: [PATCH] ppp: deflate: never return len larger than output buffer [ Upstream commit e2a4800e75780ccf4e6c2487f82b688ba736eb18 ] When we've run out of space in the output buffer to store more data, we will call zlib_deflate with a NULL output buffer until we've consumed remaining input. When this happens, olen contains the size the output buffer would have consumed iff we'd have had enough room. This can later cause skb_over_panic when ppp_generic skb_put()s the returned length. Reported-by: Iain Douglas Signed-off-by: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- drivers/net/ppp/ppp_deflate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ppp/ppp_deflate.c b/drivers/net/ppp/ppp_deflate.c index 1dbdf82a6dfd..43764cca8dac 100644 --- a/drivers/net/ppp/ppp_deflate.c +++ b/drivers/net/ppp/ppp_deflate.c @@ -268,7 +268,7 @@ static int z_compress(void *arg, unsigned char *rptr, unsigned char *obuf, /* * See if we managed to reduce the size of the packet. */ - if (olen < isize) { + if (olen < isize && olen <= osize) { state->stats.comp_bytes += olen; state->stats.comp_packets++; } else { -- 2.39.2