MIPS: traps: Fix SIGFPE information leak from `do_ov' and `do_trap_or_bp'

Avoid sending a partially initialised `siginfo_t' structure along SIGFPE
signals issued from `do_ov' and `do_trap_or_bp', leading to information
leaking from the kernel stack.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 6 insertions, 7 deletions

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index ae790c575d4f..bf14da9f3e33 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -690,15 +690,15 @@ static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
 asmlinkage void do_ov(struct pt_regs *regs)
 {
         enum ctx_state prev_state;
-        siginfo_t info;
+        siginfo_t info = {
+                .si_signo = SIGFPE,
+                .si_code = FPE_INTOVF,
+                .si_addr = (void __user *)regs->cp0_epc,
+        };
 
         prev_state = exception_enter();
         die_if_kernel("Integer overflow", regs);
 
-        info.si_code = FPE_INTOVF;
-        info.si_signo = SIGFPE;
-        info.si_errno = 0;
-        info.si_addr = (void __user *) regs->cp0_epc;
         force_sig_info(SIGFPE, &info, current);
         exception_exit(prev_state);
 }
@@ -874,7 +874,7 @@ out:
 void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
         const char *str)
 {
-        siginfo_t info;
+        siginfo_t info = { 0 };
         char b[40];
 
 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
@@ -903,7 +903,6 @@ void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
                 else
                         info.si_code = FPE_INTOVF;
                 info.si_signo = SIGFPE;
-                info.si_errno = 0;
                 info.si_addr = (void __user *) regs->cp0_epc;
                 force_sig_info(SIGFPE, &info, current);
                 break;