MIPS: Fix bounds check virt_addr_valid
diff mbox series

Message ID 20190616223039.28158-1-hauke@hauke-m.de
State Mainlined
Commit d6ed083f5cc621e15c15b56c3b585fd524dbcb0f
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Series
  • MIPS: Fix bounds check virt_addr_valid
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Commit Message

Hauke Mehrtens June 16, 2019, 10:30 p.m. UTC
The bounds check used the uninitialized variable vaddr, it should use
the given parameter kaddr instead. When using the uninitialized value
the compiler assumed it to be 0 and optimized this function to just
return 0 in all cases.

This should make the function check the range of the given address and
only do the page map check in case it is in the expected range of
virtual addresses.

Fixes: 074a1e1167af ("MIPS: Bounds check virt_addr_valid")
Cc: stable@vger.kernel.org # v4.12+
Cc: Paul Burton <paul.burton@mips.com>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
 arch/mips/mm/mmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Paul Burton June 16, 2019, 10:52 p.m. UTC | #1
Hello,

Hauke Mehrtens wrote:
> The bounds check used the uninitialized variable vaddr, it should use
> the given parameter kaddr instead. When using the uninitialized value
> the compiler assumed it to be 0 and optimized this function to just
> return 0 in all cases.
> 
> This should make the function check the range of the given address and
> only do the page map check in case it is in the expected range of
> virtual addresses.
> 
> Fixes: 074a1e1167af ("MIPS: Bounds check virt_addr_valid")
> Cc: stable@vger.kernel.org # v4.12+
> Cc: Paul Burton <paul.burton@mips.com>
> Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

Applied to mips-fixes.

Thanks,
    Paul

[ This message was auto-generated; if you believe anything is incorrect
  then please email paul.burton@mips.com to report it. ]

Patch
diff mbox series

diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
index 50ee7213b432..d79f2b432318 100644
--- a/arch/mips/mm/mmap.c
+++ b/arch/mips/mm/mmap.c
@@ -203,7 +203,7 @@  unsigned long arch_randomize_brk(struct mm_struct *mm)
 
 bool __virt_addr_valid(const volatile void *kaddr)
 {
-	unsigned long vaddr = (unsigned long)vaddr;
+	unsigned long vaddr = (unsigned long)kaddr;
 
 	if ((vaddr < PAGE_OFFSET) || (vaddr >= MAP_BASE))
 		return false;