Mark Rutland 027d0c7101 arm64: hugetlb: avoid potential NULL dereference ... The static analyzer in GCC 10 spotted that in huge_pte_alloc() we may pass a NULL pmdp into pte_alloc_map() when pmd_alloc() returns NULL: | CC arch/arm64/mm/pageattr.o | CC arch/arm64/mm/hugetlbpage.o | from arch/arm64/mm/hugetlbpage.c:10: | arch/arm64/mm/hugetlbpage.c: In function ‘huge_pte_alloc’: | ./arch/arm64/include/asm/pgtable-types.h:28:24: warning: dereference of NULL ‘pmdp’ [CWE-690] [-Wanalyzer-null-dereference] | ./arch/arm64/include/asm/pgtable.h:436:26: note: in expansion of macro ‘pmd_val’ | arch/arm64/mm/hugetlbpage.c:242:10: note: in expansion of macro ‘pte_alloc_map’ | |arch/arm64/mm/hugetlbpage.c:232:10: | |./arch/arm64/include/asm/pgtable-types.h:28:24: | ./arch/arm64/include/asm/pgtable.h:436:26: note: in expansion of macro ‘pmd_val’ | arch/arm64/mm/hugetlbpage.c:242:10: note: in expansion of macro ‘pte_alloc_map’ This can only occur when the kernel cannot allocate a page, and so is unlikely to happen in practice before other systems start failing. We can avoid this by bailing out if pmd_alloc() fails, as we do earlier in the function if pud_alloc() fails. Fixes: 66b3923a1a ("arm64: hugetlb: add support for PTE contiguous bit") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Kyrill Tkachov <kyrylo.tkachov@arm.com> Cc: <stable@vger.kernel.org> # 4.5.x- Cc: Will Deacon <will@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>		2020-05-07 09:24:15 +01:00
..
cache.S
context.c
copypage.c
dma-mapping.c
dump.c
extable.c
fault.c
flush.c
hugetlbpage.c
init.c
ioremap.c
kasan_init.c
Makefile
mmap.c
mmu.c
numa.c
pageattr.c
pgd.c
physaddr.c
proc.S
ptdump_debugfs.c