From: Steven Price <steven.pr...@arm.com> [ Upstream commit c02a98753e0a36ba65a05818626fa6adeb4e7c97 ]
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.pr...@arm.com Signed-off-by: Steven Price <steven.pr...@arm.com> Cc: Albert Ou <a...@eecs.berkeley.edu> Cc: Alexandre Ghiti <a...@ghiti.fr> Cc: Andy Lutomirski <l...@kernel.org> Cc: Ard Biesheuvel <ard.biesheu...@linaro.org> Cc: Arnd Bergmann <a...@arndb.de> Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> Cc: Borislav Petkov <b...@alien8.de> Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Christian Borntraeger <borntrae...@de.ibm.com> Cc: Dave Hansen <dave.han...@linux.intel.com> Cc: David S. Miller <da...@davemloft.net> Cc: Heiko Carstens <heiko.carst...@de.ibm.com> Cc: "H. Peter Anvin" <h...@zytor.com> Cc: Ingo Molnar <mi...@redhat.com> Cc: James Hogan <jho...@kernel.org> Cc: James Morse <james.mo...@arm.com> Cc: Jerome Glisse <jgli...@redhat.com> Cc: "Liang, Kan" <kan.li...@linux.intel.com> Cc: Mark Rutland <mark.rutl...@arm.com> Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Paul Burton <paul.bur...@mips.com> Cc: Paul Mackerras <pau...@samba.org> Cc: Paul Walmsley <paul.walms...@sifive.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Ralf Baechle <r...@linux-mips.org> Cc: Russell King <li...@armlinux.org.uk> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Vasily Gorbik <g...@linux.ibm.com> Cc: Vineet Gupta <vgu...@synopsys.com> Cc: Will Deacon <w...@kernel.org> Cc: Zong Li <zong...@sifive.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Sasha Levin <sas...@kernel.org> --- mm/pagewalk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/pagewalk.c b/mm/pagewalk.c index c2cbd26201696..a024667a9c041 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -14,9 +14,9 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, err = walk->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++; } -- 2.25.1
