arc: don't leak bits of kernel stack into coredump (7798bf21) · Commits · 戴 / test

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 <viro@zeniv.linux.org.uk>

arch/arc/kernel/signal.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -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)

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