Commit 9bf148cb authored by Colin Ian King's avatar Colin Ian King Committed by Thomas Gleixner

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: default avatarColin Ian King <colin.king@canonical.com>
Acked-by: default avatarDave 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.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent bf70e551
...@@ -123,7 +123,7 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs, ...@@ -123,7 +123,7 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs,
break; break;
} }
if (regno > nr_registers) { if (regno >= nr_registers) {
WARN_ONCE(1, "decoded an instruction with an invalid register"); WARN_ONCE(1, "decoded an instruction with an invalid register");
return -EINVAL; return -EINVAL;
} }
......
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