From: Wu Guanghao <wuguanghao3@xxxxxxxxxx>
In load_imsm_mpb() there is potential double free issue on super->buf.
The first location to free super->buf is from get_super_block() <==
load_and_parse_mpb() <== load_imsm_mpb():
4514 if (posix_memalign(&super->migr_rec_buf, MAX_SECTOR_SIZE,
4515 MIGR_REC_BUF_SECTORS*MAX_SECTOR_SIZE) != 0) {
4516 pr_err("could not allocate migr_rec buffer\n");
4517 free(super->buf);
4518 return 2;
4519 }
If the above error condition happens, super->buf is freed and value 2
is returned to get_super_block() eventually. Then in the following code
block inside load_imsm_mpb(),
5289 error:
5290 if (!err) {
5291 s->next = *super_list;
5292 *super_list = s;
5293 } else {
5294 if (s)
5295 free_imsm(s);
5296 close_fd(&dfd);
5297 }
at line 5295 when free_imsm() is called, super->buf is freed again from
the call chain free_imsm() <== __free_imsm(), in following code block,
4651 if (super->buf) {
4652 free(super->buf);
4653 super->buf = NULL;
4654 }
This patch sets super->buf as NULL after line 4517 in load_imsm_mpb()
to avoid the potential double free().
(Coly Li helps to re-compose the commit log)
Signed-off-by: Wu Guanghao <wuguanghao3@xxxxxxxxxx>
Reviewed-by: Mariusz Tkaczyk <mariusz.tkaczyk@xxxxxxxxxxxxxxx>
Acked-by: Coly Li <colyli@xxxxxxx>
---
super-intel.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/super-intel.c b/super-intel.c
index 89fac626..4a3da847 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -4515,6 +4515,7 @@ static int load_imsm_mpb(int fd, struct intel_super *super, char *devname)
MIGR_REC_BUF_SECTORS*MAX_SECTOR_SIZE) != 0) {
pr_err("could not allocate migr_rec buffer\n");
free(super->buf);
+ super->buf = NULL;
return 2;
}
super->clean_migration_record_by_mdmon = 0;
--
2.39.2
