mm/damon/sysfs: check error from damon_sysfs_update_target()

Patch series "mm/damon/sysfs: fix unhandled return values".

Some of DAMON sysfs interface code is not handling return values from some
functions.  As a result, confusing user input handling or NULL-dereference
is possible.  Check those properly.


This patch (of 3):

damon_sysfs_update_target() returns error code for failures, but its
caller, damon_sysfs_set_targets() is ignoring that.  The update function
seems making no critical change in case of such failures, but the behavior
will look like DAMON sysfs is silently ignoring or only partially
accepting the user input.  Fix it.

Link: https://lkml.kernel.org/r/20231106233408.51159-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20231106233408.51159-2-sj@kernel.org
Fixes: 19467a950b ("mm/damon/sysfs: remove requested targets when online-commit inputs")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>	[5.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
SeongJae Park 2023-11-06 23:34:06 +00:00 committed by Andrew Morton
parent a48d5bdc87
commit b4936b544b
1 changed files with 3 additions and 1 deletions

View File

@ -1203,8 +1203,10 @@ static int damon_sysfs_set_targets(struct damon_ctx *ctx,
damon_for_each_target_safe(t, next, ctx) {
if (i < sysfs_targets->nr) {
damon_sysfs_update_target(t, ctx,
err = damon_sysfs_update_target(t, ctx,
sysfs_targets->targets_arr[i]);
if (err)
return err;
} else {
if (damon_target_has_pid(ctx))
put_pid(t->pid);