From 0247bdee2581a6857a24c5ff297f01d3a3112b11 Mon Sep 17 00:00:00 2001
From: Reinhard Tartler <siretart@tauware.de>
Date: Wed, 27 Apr 2011 21:21:54 +0200
Subject: [PATCH] Fix races in default av_log handler
Prevent competing threads from overwriting (shared) buffers.
Original patch by: Michael Niedermayer <michaelni@gmx.at>
---
libavutil/log.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/libavutil/log.c b/libavutil/log.c
index deab11965de..cfeb21cd5a6 100644
--- a/libavutil/log.c
+++ b/libavutil/log.c
@@ -83,7 +83,8 @@ void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl)
{
static int print_prefix=1;
static int count;
- static char line[1024], prev[1024];
+ static char prev[1024];
+ char line[1024];
static int is_atty;
AVClass* avc= ptr ? *(AVClass**)ptr : NULL;
if(level>av_log_level)
@@ -108,7 +109,7 @@ void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl)
if(!is_atty) is_atty= isatty(2) ? 1 : -1;
#endif
- if(print_prefix && (flags & AV_LOG_SKIP_REPEATED) && !strcmp(line, prev)){
+ if(print_prefix && (flags & AV_LOG_SKIP_REPEATED) && !strncmp(line, prev, sizeof line)){
count++;
if(is_atty==1)
fprintf(stderr, " Last message repeated %d times\r", count);
@@ -119,7 +120,7 @@ void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl)
count=0;
}
colored_fputs(av_clip(level>>3, 0, 6), line);
- strcpy(prev, line);
+ strncpy(prev, line, sizeof line);
}
static void (*av_log_callback)(void*, int, const char*, va_list) = av_log_default_callback;
--
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