diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2021-10-20 20:43:59 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-25 11:49:06 +0300 |
| commit | 110ae07d2268b176c470d3b26eaddd3c5f1b157b (patch) | |
| tree | 6977523b3afca00d91ed1e799d751c8555c286d9 /kernel/signal.c | |
| parent | 21d727a394f01525f26603f1ca8db7a0e77b69f6 (diff) | |
| download | linux-110ae07d2268b176c470d3b26eaddd3c5f1b157b.tar.xz | |
signal: Implement force_fatal_sig
commit 26d5badbccddcc063dc5174a2baffd13a23322aa upstream.
Add a simple helper force_fatal_sig that causes a signal to be
delivered to a process as if the signal handler was set to SIG_DFL.
Reimplement force_sigsegv based upon this new helper. This fixes
force_sigsegv so that when it forces the default signal handler
to be used the code now forces the signal to be unblocked as well.
Reusing the tested logic in force_sig_info_to_task that was built for
force_sig_seccomp this makes the implementation trivial.
This is interesting both because it makes force_sigsegv simpler and
because there are a couple of buggy places in the kernel that call
do_exit(SIGILL) or do_exit(SIGSYS) because there is no straight
forward way today for those places to simply force the exit of a
process with the chosen signal. Creating force_fatal_sig allows
those places to be implemented with normal signal exits.
Link: https://lkml.kernel.org/r/20211020174406.17889-13-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Thomas Backlund <tmb@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index ef46309a9409..f4b8ee0e6516 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1650,6 +1650,19 @@ void force_sig(int sig) } EXPORT_SYMBOL(force_sig); +void force_fatal_sig(int sig) +{ + struct kernel_siginfo info; + + clear_siginfo(&info); + info.si_signo = sig; + info.si_errno = 0; + info.si_code = SI_KERNEL; + info.si_pid = 0; + info.si_uid = 0; + force_sig_info_to_task(&info, current, true); +} + /* * When things go south during signal handling, we * will force a SIGSEGV. And if the signal that caused @@ -1658,15 +1671,10 @@ EXPORT_SYMBOL(force_sig); */ void force_sigsegv(int sig) { - struct task_struct *p = current; - - if (sig == SIGSEGV) { - unsigned long flags; - spin_lock_irqsave(&p->sighand->siglock, flags); - p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; - spin_unlock_irqrestore(&p->sighand->siglock, flags); - } - force_sig(SIGSEGV); + if (sig == SIGSEGV) + force_fatal_sig(SIGSEGV); + else + force_sig(SIGSEGV); } int force_sig_fault_to_task(int sig, int code, void __user *addr |