From: SeongJae Park sj@kernel.org
stable inclusion from stable-v6.6.3 commit 0bf5055d5d33133c3a7cc5e4032eeb0ba7832c44 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8LBQP
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit ae636ae2bbfd9279f5681dbf320d1da817e52b68 upstream.
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 sj@kernel.org Cc: stable@vger.kernel.org [6.2+] Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- 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 527e7d17eb3b..13e29fe065ab 100644 --- a/mm/damon/sysfs-schemes.c +++ b/mm/damon/sysfs-schemes.c @@ -1752,6 +1752,8 @@ 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,