From 31c59d59c7a7963e0ceec6c35f166d19ebabf8fd Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Mon, 6 Nov 2023 23:34:08 +0000 Subject: [PATCH] UPSTREAM: mm/damon/sysfs-schemes: handle tried region directory allocation failure DAMON sysfs interface's before_damos_apply callback (damon_sysfs_before_damos_apply()), which creates the DAMOS tried regions for each DAMOS action applied region, is not handling the allocation failure for the sysfs directory data. As a result, NULL pointer derefeence is possible. Fix it by handling the case. Link: https://lkml.kernel.org/r/20231106233408.51159-4-sj@kernel.org Fixes: f1d13cacabe1 ("mm/damon/sysfs: implement DAMOS tried regions update command") Signed-off-by: SeongJae Park Cc: [6.2+] Signed-off-by: Andrew Morton (cherry picked from commit ae636ae2bbfd9279f5681dbf320d1da817e52b68) Bug: 300502883 Change-Id: I98568f4b0cee9fea82f4fe6d3e7a505370c3c304 Signed-off-by: cui yangpei --- mm/damon/sysfs-schemes.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c index b79b7c0eb9d0..12b2c903b0a0 100644 --- a/mm/damon/sysfs-schemes.c +++ b/mm/damon/sysfs-schemes.c @@ -1344,6 +1344,8 @@ static int damon_sysfs_before_damos_apply(struct damon_ctx *ctx, return 0; region = damon_sysfs_scheme_region_alloc(r); + if (!region) + return 0; list_add_tail(®ion->list, &sysfs_regions->regions_list); sysfs_regions->nr_regions++; if (kobject_init_and_add(®ion->kobj,