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* [newlib-cygwin] libm/stdlib: don't read past source in nano_realloc
@ 2020-08-17 9:45 Corinna Vinschen
0 siblings, 0 replies; only message in thread
From: Corinna Vinschen @ 2020-08-17 9:45 UTC (permalink / raw)
To: newlib-cvs
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=ce4044adeebfdc60714d3a35f67ba536edb55612
commit ce4044adeebfdc60714d3a35f67ba536edb55612
Author: Keith Packard via Newlib <newlib@sourceware.org>
Date: Thu Aug 13 17:19:01 2020 -0700
libm/stdlib: don't read past source in nano_realloc
Save the computed block size and use it to avoid reading past
the end of the source block.
Signed-off-by: Keith Packard <keithp@keithp.com>
Diff:
---
newlib/libc/stdlib/nano-mallocr.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/newlib/libc/stdlib/nano-mallocr.c b/newlib/libc/stdlib/nano-mallocr.c
index 9c59cff73..3970753a9 100644
--- a/newlib/libc/stdlib/nano-mallocr.c
+++ b/newlib/libc/stdlib/nano-mallocr.c
@@ -466,6 +466,7 @@ void * nano_realloc(RARG void * ptr, malloc_size_t size)
{
void * mem;
chunk * p_to_realloc;
+ malloc_size_t old_size;
if (ptr == NULL) return nano_malloc(RCALL size);
@@ -477,13 +478,14 @@ void * nano_realloc(RARG void * ptr, malloc_size_t size)
/* TODO: There is chance to shrink the chunk if newly requested
* size is much small */
- if (nano_malloc_usable_size(RCALL ptr) >= size)
+ old_size = nano_malloc_usable_size(RCALL ptr);
+ if (old_size >= size)
return ptr;
mem = nano_malloc(RCALL size);
if (mem != NULL)
{
- memcpy(mem, ptr, size);
+ memcpy(mem, ptr, old_size);
nano_free(RCALL ptr);
}
return mem;
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