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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2020-03-07 10:09:15 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-03-13 21:13:05 +1100 |
| commit | cc6f0e39000900e5dd1448103a9571f0eccd7d4e (patch) | |
| tree | 09f51e44728fe42929e2fd9e6aeff1a62890c4fb | |
| parent | 819723a8a2fb66678fe15d177ae56af38163f364 (diff) | |
| download | linux-cc6f0e39000900e5dd1448103a9571f0eccd7d4e.tar.gz linux-cc6f0e39000900e5dd1448103a9571f0eccd7d4e.tar.bz2 linux-cc6f0e39000900e5dd1448103a9571f0eccd7d4e.zip | |
powerpc/32: Fix missing NULL pmd check in virt_to_kpte()
Commit 2efc7c085f05 ("powerpc/32: drop get_pteptr()"),
replaced get_pteptr() by virt_to_kpte(). But virt_to_kpte() lacks a
NULL pmd check and returns an invalid non NULL pointer when there
is no page table.
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Fixes: 2efc7c085f05 ("powerpc/32: drop get_pteptr()")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b1177cdfc6af74a3e277bba5d9e708c4b3315ebe.1583575707.git.christophe.leroy@c-s.fr
| -rw-r--r-- | arch/powerpc/include/asm/pgtable.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index b80bfd41828d..b1f1d5339735 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -54,7 +54,9 @@ static inline pmd_t *pmd_ptr_k(unsigned long va) static inline pte_t *virt_to_kpte(unsigned long vaddr) { - return pte_offset_kernel(pmd_ptr_k(vaddr), vaddr); + pmd_t *pmd = pmd_ptr_k(vaddr); + + return pmd_none(*pmd) ? NULL : pte_offset_kernel(pmd, vaddr); } #endif |