From cf0d44d513f275be9ce42158079d4257e8973889 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Mon, 23 May 2016 15:35:51 +0200 Subject: [PATCH] s390: fix info leak in do_sigsegv Aleksa has reported incorrect si_errno value when stracing task which received SIGSEGV: [pid 20799] --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_errno=2510266, si_addr=0x100000000000000} The reason seems to be that do_sigsegv is not initializing siginfo structure defined on the stack completely so it will leak 4B of the previous stack content. Fix it simply by initializing si_errno to 0 (same as do_sigbus does already). Cc: stable # introduced pre-git times Reported-by: Aleksa Sarai Signed-off-by: Michal Hocko Signed-off-by: Martin Schwidefsky --- arch/s390/mm/fault.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 7a3144017301..19288c1b36d3 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -250,6 +250,7 @@ static noinline void do_sigsegv(struct pt_regs *regs, int si_code) report_user_fault(regs, SIGSEGV, 1); si.si_signo = SIGSEGV; + si.si_errno = 0; si.si_code = si_code; si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK); force_sig_info(SIGSEGV, &si, current); -- 2.20.1