logfs: Prevent memory corruption
This is a bad one. I wonder whether we were so far protected by
no_free_segments(sb) usually being smaller than LOGFS_NO_AREAS.
Found by Dan Carpenter <dan.carpenter@oracle.com> using smatch.
Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
diff --git a/fs/logfs/gc.c b/fs/logfs/gc.c
index caa4419..d4efb06 100644
--- a/fs/logfs/gc.c
+++ b/fs/logfs/gc.c
@@ -367,7 +367,7 @@
int i, max_dist;
struct gc_candidate *cand = NULL, *this;
- max_dist = min(no_free_segments(sb), LOGFS_NO_AREAS);
+ max_dist = min(no_free_segments(sb), LOGFS_NO_AREAS - 1);
for (i = max_dist; i >= 0; i--) {
this = first_in_list(&super->s_low_list[i]);