From: Lasse Collin <lasse.collin@tukaani.org>
Date: Mon, 7 Mar 2022 08:06:31 +0000 (+0100)
Subject: xz: fix XZ_DYNALLOC to avoid useless memory reallocations
X-Git-Tag: archive/raspbian/4.17.0-1+rpi1^2~33^2~857
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=22d5d1c0d18893d9cb92b322f95d7ebab6c0cfd9;p=xen.git

xz: fix XZ_DYNALLOC to avoid useless memory reallocations

s->dict.allocated was initialized to 0 but never set after a successful
allocation, thus the code always thought that the dictionary buffer has
to be reallocated.

Link: http://lkml.kernel.org/r/20191104185107.3b6330df@tukaani.org
Reported-by: Yu Sun <yusun2@cisco.com>
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Acked-by: Daniel Walker <danielwa@cisco.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 8e20ba2e53fc
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/common/xz/dec_lzma2.c b/xen/common/xz/dec_lzma2.c
index 6b07722e3c..68bcf0f29a 100644
--- a/xen/common/xz/dec_lzma2.c
+++ b/xen/common/xz/dec_lzma2.c
@@ -1146,6 +1146,7 @@ XZ_EXTERN enum xz_ret __init xz_dec_lzma2_reset(struct xz_dec_lzma2 *s, uint8_t
 
 		if (DEC_IS_DYNALLOC(s->dict.mode)) {
 			if (s->dict.allocated < s->dict.size) {
+				s->dict.allocated = s->dict.size;
 				large_free(s->dict.buf);
 				s->dict.buf = large_malloc(s->dict.size);
 				if (s->dict.buf == NULL) {