From d6103b83c6c020de8a0b5e0e28bdcfd74eb1351e Mon Sep 17 00:00:00 2001 From: Lasse Collin Date: Wed, 19 Dec 2012 12:28:13 +0100 Subject: [PATCH] XZ decompressor: Fix decoding of empty LZMA2 streams From: Lasse Collin The old code considered valid empty LZMA2 streams to be corrupt. Note that a typical empty .xz file has no LZMA2 data at all, and thus most .xz files having no uncompressed data are handled correctly even without this fix. Signed-off-by: Lasse Collin Signed-off-by: Jan Beulich xen-unstable changeset: 23869:db1ea4b127cd xen-unstable date: Thu Sep 22 17:33:48 UTC 2011 --- xen/common/xz/dec_lzma2.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/xen/common/xz/dec_lzma2.c b/xen/common/xz/dec_lzma2.c index d4e8264b7b..779221dfa5 100644 --- a/xen/common/xz/dec_lzma2.c +++ b/xen/common/xz/dec_lzma2.c @@ -969,6 +969,9 @@ XZ_EXTERN enum xz_ret INIT xz_dec_lzma2_run(struct xz_dec_lzma2 *s, */ tmp = b->in[b->in_pos++]; + if (tmp == 0x00) + return XZ_STREAM_END; + if (tmp >= 0xE0 || tmp == 0x01) { s->lzma2.need_props = true; s->lzma2.need_dict_reset = false; @@ -1001,9 +1004,6 @@ XZ_EXTERN enum xz_ret INIT xz_dec_lzma2_run(struct xz_dec_lzma2 *s, lzma_reset(s); } } else { - if (tmp == 0x00) - return XZ_STREAM_END; - if (tmp > 0x02) return XZ_DATA_ERROR;