Messages in this thread Patch in this message | | | Date | Fri, 26 Feb 2016 13:15:43 -0800 | From | tip-bot for Colin Ian King <> | Subject | [tip:x86/urgent] x86/mpx: Fix off-by-one comparison with nr_registers |
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Commit-ID: 9bf148cb0812595bfdf5100bd2c07e9bec9c6ef5 Gitweb: http://git.kernel.org/tip/9bf148cb0812595bfdf5100bd2c07e9bec9c6ef5 Author: Colin Ian King <colin.king@canonical.com> AuthorDate: Fri, 26 Feb 2016 18:55:31 +0000 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Fri, 26 Feb 2016 22:12:47 +0100
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: fcc7ffd67991 "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> --- arch/x86/mm/mpx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c index b2fd67d..ef05755 100644 --- a/arch/x86/mm/mpx.c +++ b/arch/x86/mm/mpx.c @@ -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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