7df6795d4c
zlib through 1.2.12 has a heap-based buffer over-read or buffer overflow in inflate in inflate.c via a large gzip header extra field. NOTE: only applications that call inflateGetHeader are affected. Some common applications bundle the affected zlib source code but may be unable to call inflateGetHeader. Fixes: CVE-2022-37434 References: https://github.com/ivd38/zlib_overflow Signed-off-by: Petr Štetiar <ynezz@true.cz>
33 lines
1.4 KiB
Diff
33 lines
1.4 KiB
Diff
From eff308af425b67093bab25f80f1ae950166bece1 Mon Sep 17 00:00:00 2001
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From: Mark Adler <fork@madler.net>
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Date: Sat, 30 Jul 2022 15:51:11 -0700
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Subject: [PATCH] Fix a bug when getting a gzip header extra field with
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inflate().
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If the extra field was larger than the space the user provided with
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inflateGetHeader(), and if multiple calls of inflate() delivered
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the extra header data, then there could be a buffer overflow of the
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provided space. This commit assures that provided space is not
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exceeded.
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---
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inflate.c | 5 +++--
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1 file changed, 3 insertions(+), 2 deletions(-)
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diff --git a/inflate.c b/inflate.c
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index 7be8c6366..7a7289749 100644
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--- a/inflate.c
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+++ b/inflate.c
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@@ -763,9 +763,10 @@ int flush;
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copy = state->length;
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if (copy > have) copy = have;
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if (copy) {
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+ len = state->head->extra_len - state->length;
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if (state->head != Z_NULL &&
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- state->head->extra != Z_NULL) {
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- len = state->head->extra_len - state->length;
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+ state->head->extra != Z_NULL &&
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+ len < state->head->extra_max) {
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zmemcpy(state->head->extra + len, next,
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len + copy > state->head->extra_max ?
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state->head->extra_max - len : copy);
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