Re: [PATCH v2 04/12] ss_add_info_dir: fix memory leak and check whether
From: "Theodore Y. Ts'o" <tytso@mit.edu>
Date: 2021-07-16 03:27:56
On Wed, Jun 30, 2021 at 04:27:16PM +0800, wuguanghao wrote:
quoted hunk ↗ jump to hunk
In ss_add_info_dir(), need free info->info_dirs before return, otherwise it will cause memory leak. At the same time, it is necessary to check whether dirs[n_dirs] is a null pointer, otherwise a segmentation fault will occur. Signed-off-by: Wu Guanghao <redacted> Signed-off-by: Zhiqiang Liu <redacted> Reviewed-by: Wu Bo <redacted> --- lib/ss/help.c | 5 +++++ 1 file changed, 5 insertions(+)diff --git a/lib/ss/help.c b/lib/ss/help.c index 5204401b..6768b9b1 100644 --- a/lib/ss/help.c +++ b/lib/ss/help.c@@ -148,6 +148,7 @@ void ss_add_info_dir(int sci_idx, char *info_dir, int *code_ptr) dirs = (char **)realloc((char *)dirs, (unsigned)(n_dirs + 2)*sizeof(char *)); if (dirs == (char **)NULL) { + free(info->info_dirs); info->info_dirs = (char **)NULL; *code_ptr = errno; return;
Adding the free() isn't right fix. The real problem is that this line
should be removed:
info->info_dirs = (char **)NULL;
The function is trying to add a string (a directory name) to list, and
the realloc() is trying to extend the list. If the realloc fils, we
shouldn't be zapping the original list. We should just be returning,
and leaving the original list of directories unchanged and untouched.
- Ted