@@ -353,6 +353,7 @@ static ssize_t dbgfs_target_ids_write(st
const char __user *buf, size_t count, loff_t *ppos)
{
struct damon_ctx *ctx = file->private_data;
+ struct damon_target *t, *next_t;
bool id_is_pid = true;
char *kbuf, *nrs;
unsigned long *targets;
@@ -397,8 +398,12 @@ static ssize_t dbgfs_target_ids_write(st
goto unlock_out;
}
- /* remove targets with previously-set primitive */
- damon_set_targets(ctx, NULL, 0);
+ /* remove previously set targets */
+ damon_for_each_target_safe(t, next_t, ctx) {
+ if (targetid_is_pid(ctx))
+ put_pid((struct pid *)t->id);
+ damon_destroy_target(t);
+ }
/* Configure the context for the address space type */
if (id_is_pid)
The patch titled Subject: mm/damon/dbgfs: fix 'struct pid' leaks in 'dbgfs_target_ids_write()' has been added to the -mm tree. Its filename is mm-damon-dbgfs-fix-struct-pid-leaks-in-dbgfs_target_ids_write.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-damon-dbgfs-fix-struct-pid-leaks-in-dbgfs_target_ids_write.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-damon-dbgfs-fix-struct-pid-leaks-in-dbgfs_target_ids_write.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: SeongJae Park <sj@kernel.org> Subject: mm/damon/dbgfs: fix 'struct pid' leaks in 'dbgfs_target_ids_write()' DAMON debugfs interface increases the reference counts of 'struct pid's for targets from the 'target_ids' file write callback ('dbgfs_target_ids_write()'), but decreases the counts only in DAMON monitoring termination callback ('dbgfs_before_terminate()'). Therefore, when 'target_ids' file is repeatedly written without DAMON monitoring start/termination, the reference count is not decreased and therefore memory for the 'struct pid' cannot be freed. This commit fixes this issue by decreasing the reference counts when 'target_ids' is written. Link: https://lkml.kernel.org/r/20211229124029.23348-1-sj@kernel.org Fixes: 4bc05954d007 ("mm/damon: implement a debugfs-based user space interface") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [5.15+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- mm/damon/dbgfs.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)