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-Tag: v3.12.67~29 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9b2f30c7fa84247064d8095e57caed630476475a;p=thirdparty%2Fkernel%2Fstable.git 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 Signed-off-by: Jiri Slaby --- diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c index a0c63fc48457d..ca6bcd132a149 100644 --- a/arch/arc/kernel/signal.c +++ b/arch/arc/kernel/signal.c @@ -80,13 +80,14 @@ 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; - return err; + set_current_blocked(&set); + + return 0; } static inline int is_do_ss_needed(unsigned int magic)