From: Al Viro Date: Sat, 10 Sep 2016 20:31:04 +0000 (-0400) Subject: arc: don't leak bits of kernel stack into coredump X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=7798bf2140ebcc36eafec6a4194fffd8d585d471;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git arc: don't leak bits of kernel stack into coredump 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... Cc: stable@vger.kernel.org Signed-off-by: Al Viro --- diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c index 6cb3736b6b83..d347bbc086fe 100644 --- a/arch/arc/kernel/signal.c +++ b/arch/arc/kernel/signal.c @@ -107,13 +107,13 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf) struct user_regs_struct uregs; err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); - if (!err) - set_current_blocked(&set); - err |= __copy_from_user(&uregs.scratch, &(sf->uc.uc_mcontext.regs.scratch), sizeof(sf->uc.uc_mcontext.regs.scratch)); + if (err) + return err; + set_current_blocked(&set); regs->bta = uregs.scratch.bta; regs->lp_start = uregs.scratch.lp_start; regs->lp_end = uregs.scratch.lp_end; @@ -138,7 +138,7 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf) regs->r0 = uregs.scratch.r0; regs->sp = uregs.scratch.sp; - return err; + return 0; } static inline int is_do_ss_needed(unsigned int magic)