Commit 9bf148cb authored Feb 26, 2016 by Colin Ian King Committed by Thomas Gleixner Feb 26, 2016

x86/mpx: Fix off-by-one comparison with nr_registers



In the unlikely event that regno == nr_registers then we get an array
overrun on regoff because the invalid register check is currently
off-by-one. Fix this with a check that regno is >= nr_registers instead.

Detected with static analysis using CoverityScan.

Fixes: fcc7ffd6 "x86, mpx: Decode MPX instruction to get bound violation information"
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1456512931-3388-1-git-send-email-colin.king@canonical.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent bf70e551

arch/x86/mm/mpx.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -123,7 +123,7 @@ static int get_reg_offset(struct insn insn, struct pt_regs regs,
		break;
		}

		if (regno > nr_registers) {
		if (regno >= nr_registers) {
		WARN_ONCE(1, "decoded an instruction with an invalid register");
		return -EINVAL;
		}

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