From: Tianyang Zhang <zhangtianyang@loongson.cn> LoongArch inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICB2S5 CVE: NA -------------------------------- Fixes: bd51834d1cf6 ("LoongArch: Return NULL from huge_pte_offset() for invalid PMD") ERROR INFO: CPU 25 Unable to handle kernel paging request at virtual address 0x0 ... Call Trace: [<900000000023c30c>] huge_pte_offset+0x3c/0x58 [<900000000057fd4c>] hugetlb_follow_page_mask+0x74/0x438 [<900000000051fee8>] __get_user_pages+0xe0/0x4c8 [<9000000000522414>] faultin_page_range+0x84/0x380 [<9000000000564e8c>] madvise_vma_behavior+0x534/0xa48 [<900000000056689c>] do_madvise+0x1bc/0x3e8 [<9000000000566df4>] sys_madvise+0x24/0x38 [<90000000015b9e88>] do_syscall+0x78/0x98 [<9000000000221f18>] handle_syscall+0xb8/0x158 In some cases, pmd may be NULL and rely on NULL as the return value for processing, so it is necessary to determine this situation here Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn> Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn> --- arch/loongarch/mm/hugetlbpage.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/loongarch/mm/hugetlbpage.c b/arch/loongarch/mm/hugetlbpage.c index aca52c42e94e..fb09fb70661e 100644 --- a/arch/loongarch/mm/hugetlbpage.c +++ b/arch/loongarch/mm/hugetlbpage.c @@ -47,7 +47,8 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, pmd = pmd_offset(pud, addr); } } - return pmd_none(pmdp_get(pmd)) ? NULL : (pte_t *) pmd; + + return (!pmd || pmd_none(pmdp_get(pmd))) ? NULL : (pte_t *) pmd; } int pmd_huge(pmd_t pmd) -- 2.33.0