From 7fbeab3c65e91069096a7a5811abf91262d67ec0 Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Mon, 6 Nov 2023 23:34:06 +0000 Subject: [PATCH] UPSTREAM: 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: 19467a950b49 ("mm/damon/sysfs: remove requested targets when online-commit inputs") Signed-off-by: SeongJae Park Cc: [5.19+] Signed-off-by: Andrew Morton (cherry picked from commit b4936b544b08ed44949055b92bd25f77759ebafc) Bug: 300502883 Change-Id: I9bfea66f76ad094ed73defee5ff3fdb3794e8162 Signed-off-by: cui yangpei --- mm/damon/sysfs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c index 6545a46da606..0a6b4625de9f 100644 --- a/mm/damon/sysfs.c +++ b/mm/damon/sysfs.c @@ -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);