36 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			36 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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| 
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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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| 
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| diff --git a/inflate.c b/inflate.c
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| index 7be8c63..7a72897 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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| -- 
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| 2.35.3
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| 
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