Hi!
FFmpeg has an arbitrary allocation limit (2G iirc), av_fast_realloc()
increases the allocation even if the requested is equal the already
allocated size. I believe this can lead to unnecessary OOM (no
testcase) if the requested (and already allocated) size is close to
our limit.
Additionally, this avoids an over-allocation for the mov stts patch I just sent.
Attached patch changes the behaviour introduced 15 years ago.
Please comment, Carl Eugen
From 0ad7a0517c69d04a4443e66eeec802bda21aea55 Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <ceffm...@gmail.com>
Date: Sat, 30 Dec 2017 14:38:33 +0100
Subject: [PATCH] lavu/mem: Do not realloc in av_fast_realloc() if size ==
min_size.
This can avoid OOM for min_size close to FFmpeg's arbitrary alloc limits.
---
libavutil/mem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libavutil/mem.c b/libavutil/mem.c
index 79e8b59..0729e1d 100644
--- a/libavutil/mem.c
+++ b/libavutil/mem.c
@@ -463,7 +463,7 @@ void av_memcpy_backptr(uint8_t *dst, int back, int cnt)
void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size)
{
- if (min_size < *size)
+ if (min_size <= *size)
return ptr;
min_size = FFMAX(min_size + min_size / 16 + 32, min_size);
--
1.7.10.4
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