Commit d4c9dbc6 authored Sep 07, 2012 by Jan Beulich Committed by Ingo Molnar Sep 07, 2012

x86/mm: Fix range check in tlbflush debugfs interface



Since the shift count settable there is used for shifting values
of type "unsigned long", its value must not match or exceed
BITS_PER_LONG (otherwise the shift operations are undefined).

Similarly, the value must not be negative (but -1 must be
permitted, as that's the value used to distinguish the case of
the fine grained flushing being disabled).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Alex Shi <alex.shi@intel.com>
Link: http://lkml.kernel.org/r/5049B65C020000780009990C@nat28.tlf.novell.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 057237bb

arch/x86/mm/tlb.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -320,7 +320,7 @@ static ssize_t tlbflush_write_file(struct file *file,
		if (kstrtos8(buf, 0, &shift))
		return -EINVAL;

		if (shift > 64)
		if (shift < -1 \|\| shift >= BITS_PER_LONG)
		return -EINVAL;

		tlb_flushall_shift = shift;

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