From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric W. Biederman" Subject: [PATCH 02/10] signal: Properly deliver SIGILL from uprobes Date: Mon, 3 Sep 2018 22:44:22 +0200 Message-ID: <20180903204430.25473-2-ebiederm@xmission.com> References: <87musyl3fa.fsf@xmission.com> Return-path: In-Reply-To: <87musyl3fa.fsf@xmission.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Oleg Nesterov , Linus Torvalds , linux-api@vger.kernel.org, "Eric W. Biederman" List-Id: linux-api@vger.kernel.org For userspace to tell the difference between a random signal and an exception, the exception must include siginfo information. Using SEND_SIG_FORCED for SIGILL is thus wrong, and it will result in userspace seeing si_code == SI_USER (like a random signal) instead of si_code == SI_KERNEL or a more specific si_code as all exceptions deliver. Therefore replace force_sig_info(SIGILL, SEND_SIG_FORCE, current) with force_sig(SIG_ILL, current) which gets this right and is shorter and easier to type. Fixes: 014940bad8e4 ("uprobes/x86: Send SIGILL if arch_uprobe_post_xol() fails") Fixes: 0b5256c7f173 ("uprobes: Send SIGILL if handle_trampoline() fails") Signed-off-by: "Eric W. Biederman" --- kernel/events/uprobes.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 3207a4d26849..2bf792d22087 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1858,7 +1858,7 @@ static void handle_trampoline(struct pt_regs *regs) sigill: uprobe_warn(current, "handle uretprobe, sending SIGILL."); - force_sig_info(SIGILL, SEND_SIG_FORCED, current); + force_sig(SIGILL, current); } @@ -1966,7 +1966,7 @@ static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs) if (unlikely(err)) { uprobe_warn(current, "execute the probed insn, sending SIGILL."); - force_sig_info(SIGILL, SEND_SIG_FORCED, current); + force_sig(SIGILL, current); } } -- 2.17.1