Unverified Commit cdac497b authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!10697 mm: prevent derefencing NULL ptr in pfn_section_valid() 

Merge Pull Request from: @ci-robot 
 
PR sync from: Tong Tiangen <tongtiangen@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/ZTZQO5DJUTZA4PX2TYGKUB5QFWWZL5J4/ 
 
https://gitee.com/src-openeuler/kernel/issues/IAGEL6 
 
Link:https://gitee.com/openeuler/kernel/pulls/10697

 

Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
parents aeeb8bf5 5682f391

include/linux/mmzone.h

+2 −1
Original line number Diff line number Diff line
@@ -1391,8 +1391,9 @@ static inline int subsection_map_index(unsigned long pfn) 
static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)

{

	int idx = subsection_map_index(pfn);

	struct mem_section_usage *usage = READ_ONCE(ms->usage);



	return test_bit(idx, READ_ONCE(ms->usage)->subsection_map);

	return usage ? test_bit(idx, usage->subsection_map) : 0;

}

#else

static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)