The patch titled Subject: mm/damon/sysfs: check error from damon_sysfs_update_target() has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-damon-sysfs-check-error-from-damon_sysfs_update_target.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-sysfs-check-error-from-damon_sysfs_update_target.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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 via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: SeongJae Park <sj@xxxxxxxxxx> Subject: mm/damon/sysfs: check error from damon_sysfs_update_target() Date: Mon, 6 Nov 2023 23:34:06 +0000 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@xxxxxxxxxx Link: https://lkml.kernel.org/r/20231106233408.51159-2-sj@xxxxxxxxxx Fixes: 19467a950b49 ("mm/damon/sysfs: remove requested targets when online-commit inputs") Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [5.19+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/damon/sysfs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/mm/damon/sysfs.c~mm-damon-sysfs-check-error-from-damon_sysfs_update_target +++ a/mm/damon/sysfs.c @@ -1203,8 +1203,10 @@ static int damon_sysfs_set_targets(struc 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); _ Patches currently in -mm which might be from sj@xxxxxxxxxx are mm-damon-sysfs-check-error-from-damon_sysfs_update_target.patch mm-damon-sysfs-schemes-handle-tried-regions-sysfs-directory-allocation-failure.patch mm-damon-sysfs-schemes-handle-tried-region-directory-allocation-failure.patch