[PATCH 6.1 013/473] tools/nolibc/stdlib: fix memory error in realloc()

Greg Kroah-Hartman
2024-06-06T14:12:21Z

From: Brennan Xavier McManus <bxmcmanus@gmail.com>

commit 791f4641142e2aced85de082e5783b4fb0b977c2 upstream.

Pass user_p_len to memcpy() instead of heap->len to prevent realloc()
from copying an extra sizeof(heap) bytes from beyond the allocated
region.

Signed-off-by: Brennan Xavier McManus <bxmcmanus@gmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Fixes: 0e0ff638400be8f497a35b51a4751fd823f6bd6a ("tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`")
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/include/nolibc/stdlib.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/include/nolibc/stdlib.h
+++ b/tools/include/nolibc/stdlib.h
@@ -166,7 +166,7 @@ void *realloc(void *old_ptr, size_t new_
if (__builtin_expect(!ret, 0))
return NULL;

- memcpy(ret, heap->user_p, heap->len);
+ memcpy(ret, heap->user_p, user_p_len);
munmap(heap, heap->len);
return ret;
}