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| author |  Christophe Leroy <christophe.leroy@c-s.fr>
| 2020-01-24 11:54:40 +0000 |
|---|---|---|
| committer |  Michael Ellerman <mpe@ellerman.id.au>
| 2020-01-28 23:13:17 +1100 |
| commit | 6ec20aa2e510b6297906c45f009aa08b2d97269a (patch) | |
| tree | 0f2bb05b0963cd7aa4666aa21fa49d01c049bbf1 /arch/powerpc/include/asm/nohash/32/kup-8xx.h | |
| parent | readdir: make user_access_begin() use the real access range (diff) | |
| download | linux-6ec20aa2e510b6297906c45f009aa08b2d97269a.tar.gz linux-6ec20aa2e510b6297906c45f009aa08b2d97269a.tar.bz2 linux-6ec20aa2e510b6297906c45f009aa08b2d97269a.zip | |
powerpc/32s: Fix bad_kuap_fault()
At the moment, bad_kuap_fault() reports a fault only if a bad access
to userspace occurred while access to userspace was not granted.
But if a fault occurs for a write outside the allowed userspace
segment(s) that have been unlocked, bad_kuap_fault() fails to
detect it and the kernel loops forever in do_page_fault().
Fix it by checking that the accessed address is within the allowed
range.
Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f48244e9485ada0a304ed33ccbb8da271180c80d.1579866752.git.christophe.leroy@c-s.fr
Diffstat (limited to 'arch/powerpc/include/asm/nohash/32/kup-8xx.h')
| -rw-r--r-- | arch/powerpc/include/asm/nohash/32/kup-8xx.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h index 1006a427e99c..f2fea603b929 100644 --- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h +++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h @@ -46,7 +46,8 @@ static inline void prevent_user_access(void __user *to, const void __user *from, mtspr(SPRN_MD_AP, MD_APG_KUAP); } -static inline bool bad_kuap_fault(struct pt_regs *regs, bool is_write) +static inline bool +bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) { return WARN(!((regs->kuap ^ MD_APG_KUAP) & 0xf0000000), "Bug: fault blocked by AP register !"); |