Add check for the return value of __pgd_alloc() in pgd_alloc() to prevent null pointer dereference.

Fixes: a9b3c355c2e6 ("asm-generic: pgalloc: provide generic __pgd_{alloc,free}") Cc: stable@vger.kernel.org Signed-off-by: Haoxiang Li haoxiang_li2024@163.com --- arch/m68k/include/asm/sun3_pgalloc.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/m68k/include/asm/sun3_pgalloc.h b/arch/m68k/include/asm/sun3_pgalloc.h index f1ae4ed890db..80afc3a18724 100644 --- a/arch/m68k/include/asm/sun3_pgalloc.h +++ b/arch/m68k/include/asm/sun3_pgalloc.h @@ -44,8 +44,10 @@ static inline pgd_t * pgd_alloc(struct mm_struct *mm) pgd_t *new_pgd;

new_pgd = __pgd_alloc(mm, 0); - memcpy(new_pgd, swapper_pg_dir, PAGE_SIZE); - memset(new_pgd, 0, (PAGE_OFFSET >> PGDIR_SHIFT)); + if (likely(new_pgd != NULL)) { + memcpy(new_pgd, swapper_pg_dir, PAGE_SIZE); + memset(new_pgd, 0, (PAGE_OFFSET >> PGDIR_SHIFT)); + } return new_pgd; }