| From f058d09604dc4469c0d7875ed102572c45dae8d9 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 19 Jul 2018 20:33:53 -0500 |
| Subject: signal: Properly deliver SIGILL from uprobes |
| |
| From: Eric W. Biederman <ebiederm@xmission.com> |
| |
| [ Upstream commit 55a3235fc71bf34303e34a95eeee235b2d2a35dd ] |
| |
| 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") |
| Reviewed-by: Thomas Gleixner <tglx@linutronix.de> |
| Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| 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 578d4ac54484f..c173e4131df88 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); |
| |
| } |
| |
| @@ -1974,7 +1974,7 @@ 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); |
| } |
| } |
| |
| -- |
| 2.20.1 |
| |