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authorSteven Price <steven.price@arm.com>2020-02-03 17:35:58 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-02-04 03:05:25 +0000
commitc02a98753e0a36ba65a05818626fa6adeb4e7c97 (patch)
treedb22aa64fa6cd58d009d97169abf270cd5dbb534
parentfbf56346b855872db45af7c1274180f9d91f46cd (diff)
mm: pagewalk: fix termination condition in walk_pte_range()
If walk_pte_range() is called with a 'end' argument that is beyond the last page of memory (e.g. ~0UL) then the comparison between 'addr' and 'end' will always fail and the loop will be infinite. Instead change the comparison to >= while accounting for overflow. Link: http://lkml.kernel.org/r/20191218162402.45610-15-steven.price@arm.com Signed-off-by: Steven Price <steven.price@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Liang, Kan" <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Zong Li <zong.li@sifive.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/pagewalk.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 4b5ee92ba079..6732fc7ac4c8 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -14,9 +14,9 @@ static int walk_pte_range_inner(pte_t *pte, unsigned long addr,
err = ops->pte_entry(pte, addr, addr + PAGE_SIZE, walk);
if (err)
break;
- addr += PAGE_SIZE;
- if (addr == end)
+ if (addr >= end - PAGE_SIZE)
break;
+ addr += PAGE_SIZE;
pte++;
}
return err;