From 5974db8fe4a54a6d490f5b9121250fb5105c4157 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 10 Sep 2016 16:31:04 -0400 Subject: [PATCH] arc: don't leak bits of kernel stack into coredump commit 7798bf2140ebcc36eafec6a4194fffd8d585d471 upstream. On faulting sigreturn we do get SIGSEGV, all right, but anything we'd put into pt_regs could end up in the coredump. And since __copy_from_user() never zeroed on arc, we'd better bugger off on its failure without copying random uninitialized bits of kernel stack into pt_regs... Signed-off-by: Al Viro [bwh: Backported to 3.16: - Adjust context - Don't change the single return statement] Signed-off-by: Ben Hutchings --- arch/arc/kernel/signal.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c index a0c63fc48457d..0943ff84f28fb 100644 --- a/arch/arc/kernel/signal.c +++ b/arch/arc/kernel/signal.c @@ -80,11 +80,12 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf) int err; err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); - if (!err) - set_current_blocked(&set); - err |= __copy_from_user(regs, &(sf->uc.uc_mcontext.regs.scratch), sizeof(sf->uc.uc_mcontext.regs.scratch)); + if (err) + return err; + + set_current_blocked(&set); return err; } -- 2.47.3