From: Oleg Nesterov <oleg@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Deepa Dinamani <deepa.kernel@gmail.com>
Cc: linux-kernel@vger.kernel.org, arnd@arndb.de, dbueso@suse.de,
axboe@kernel.dk, dave@stgolabs.net, e@80x24.org,
jbaron@akamai.com, linux-fsdevel@vger.kernel.org,
linux-aio@kvack.org, omar.kilani@gmail.com, tglx@linutronix.de,
stable@vger.kernel.org, Al Viro <viro@ZenIV.linux.org.uk>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
David Laight <David.Laight@ACULAB.COM>
Subject: [PATCH] signal: remove the wrong signal_pending() check in restore_user_sigmask()
Date: Tue, 4 Jun 2019 15:41:17 +0200 [thread overview]
Message-ID: <20190604134117.GA29963@redhat.com> (raw)
In-Reply-To: <20190529161157.GA27659@redhat.com>
This is the minimal fix for stable, I'll send cleanups later.
The commit 854a6ed56839a40f6b5d02a2962f48841482eec4 ("signal: Add
restore_user_sigmask()") introduced the visible change which breaks
user-space: a signal temporary unblocked by set_user_sigmask() can
be delivered even if the caller returns success or timeout.
Change restore_user_sigmask() to accept the additional "interrupted"
argument which should be used instead of signal_pending() check, and
update the callers.
Reported-by: Eric Wong <e@80x24.org>
Fixes: 854a6ed56839a40f6b5d02a2962f48841482eec4 ("signal: Add restore_user_sigmask()")
cc: stable@vger.kernel.org (v5.0+)
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
fs/aio.c | 28 ++++++++++++++++++++--------
fs/eventpoll.c | 4 ++--
fs/io_uring.c | 7 ++++---
fs/select.c | 18 ++++++------------
include/linux/signal.h | 2 +-
kernel/signal.c | 5 +++--
6 files changed, 36 insertions(+), 28 deletions(-)
diff --git a/fs/aio.c b/fs/aio.c
index 3490d1f..c1e581d 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -2095,6 +2095,7 @@ SYSCALL_DEFINE6(io_pgetevents,
struct __aio_sigset ksig = { NULL, };
sigset_t ksigmask, sigsaved;
struct timespec64 ts;
+ bool interrupted;
int ret;
if (timeout && unlikely(get_timespec64(&ts, timeout)))
@@ -2108,8 +2109,10 @@ SYSCALL_DEFINE6(io_pgetevents,
return ret;
ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL);
- restore_user_sigmask(ksig.sigmask, &sigsaved);
- if (signal_pending(current) && !ret)
+
+ interrupted = signal_pending(current);
+ restore_user_sigmask(ksig.sigmask, &sigsaved, interrupted);
+ if (interrupted && !ret)
ret = -ERESTARTNOHAND;
return ret;
@@ -2128,6 +2131,7 @@ SYSCALL_DEFINE6(io_pgetevents_time32,
struct __aio_sigset ksig = { NULL, };
sigset_t ksigmask, sigsaved;
struct timespec64 ts;
+ bool interrupted;
int ret;
if (timeout && unlikely(get_old_timespec32(&ts, timeout)))
@@ -2142,8 +2146,10 @@ SYSCALL_DEFINE6(io_pgetevents_time32,
return ret;
ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL);
- restore_user_sigmask(ksig.sigmask, &sigsaved);
- if (signal_pending(current) && !ret)
+
+ interrupted = signal_pending(current);
+ restore_user_sigmask(ksig.sigmask, &sigsaved, interrupted);
+ if (interrupted && !ret)
ret = -ERESTARTNOHAND;
return ret;
@@ -2193,6 +2199,7 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents,
struct __compat_aio_sigset ksig = { NULL, };
sigset_t ksigmask, sigsaved;
struct timespec64 t;
+ bool interrupted;
int ret;
if (timeout && get_old_timespec32(&t, timeout))
@@ -2206,8 +2213,10 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents,
return ret;
ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL);
- restore_user_sigmask(ksig.sigmask, &sigsaved);
- if (signal_pending(current) && !ret)
+
+ interrupted = signal_pending(current);
+ restore_user_sigmask(ksig.sigmask, &sigsaved, interrupted);
+ if (interrupted && !ret)
ret = -ERESTARTNOHAND;
return ret;
@@ -2226,6 +2235,7 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents_time64,
struct __compat_aio_sigset ksig = { NULL, };
sigset_t ksigmask, sigsaved;
struct timespec64 t;
+ bool interrupted;
int ret;
if (timeout && get_timespec64(&t, timeout))
@@ -2239,8 +2249,10 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents_time64,
return ret;
ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL);
- restore_user_sigmask(ksig.sigmask, &sigsaved);
- if (signal_pending(current) && !ret)
+
+ interrupted = signal_pending(current);
+ restore_user_sigmask(ksig.sigmask, &sigsaved, interrupted);
+ if (interrupted && !ret)
ret = -ERESTARTNOHAND;
return ret;
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index c6f5131..4c74c76 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -2325,7 +2325,7 @@ SYSCALL_DEFINE6(epoll_pwait, int, epfd, struct epoll_event __user *, events,
error = do_epoll_wait(epfd, events, maxevents, timeout);
- restore_user_sigmask(sigmask, &sigsaved);
+ restore_user_sigmask(sigmask, &sigsaved, error == -EINTR);
return error;
}
@@ -2350,7 +2350,7 @@ COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd,
err = do_epoll_wait(epfd, events, maxevents, timeout);
- restore_user_sigmask(sigmask, &sigsaved);
+ restore_user_sigmask(sigmask, &sigsaved, err == -EINTR);
return err;
}
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 0fbb486..1147c5d 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2201,11 +2201,12 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
}
ret = wait_event_interruptible(ctx->wait, io_cqring_events(ring) >= min_events);
- if (ret == -ERESTARTSYS)
- ret = -EINTR;
if (sig)
- restore_user_sigmask(sig, &sigsaved);
+ restore_user_sigmask(sig, &sigsaved, ret == -ERESTARTSYS);
+
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
return READ_ONCE(ring->r.head) == READ_ONCE(ring->r.tail) ? ret : 0;
}
diff --git a/fs/select.c b/fs/select.c
index 6cbc9ff..a4d8f6e 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -758,10 +758,9 @@ static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp,
return ret;
ret = core_sys_select(n, inp, outp, exp, to);
+ restore_user_sigmask(sigmask, &sigsaved, ret == -ERESTARTNOHAND);
ret = poll_select_copy_remaining(&end_time, tsp, type, ret);
- restore_user_sigmask(sigmask, &sigsaved);
-
return ret;
}
@@ -1106,8 +1105,7 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,
ret = do_sys_poll(ufds, nfds, to);
- restore_user_sigmask(sigmask, &sigsaved);
-
+ restore_user_sigmask(sigmask, &sigsaved, ret == -EINTR);
/* We can restart this syscall, usually */
if (ret == -EINTR)
ret = -ERESTARTNOHAND;
@@ -1142,8 +1140,7 @@ SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds,
ret = do_sys_poll(ufds, nfds, to);
- restore_user_sigmask(sigmask, &sigsaved);
-
+ restore_user_sigmask(sigmask, &sigsaved, ret == -EINTR);
/* We can restart this syscall, usually */
if (ret == -EINTR)
ret = -ERESTARTNOHAND;
@@ -1350,10 +1347,9 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp,
return ret;
ret = compat_core_sys_select(n, inp, outp, exp, to);
+ restore_user_sigmask(sigmask, &sigsaved, ret == -ERESTARTNOHAND);
ret = poll_select_copy_remaining(&end_time, tsp, type, ret);
- restore_user_sigmask(sigmask, &sigsaved);
-
return ret;
}
@@ -1425,8 +1421,7 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds,
ret = do_sys_poll(ufds, nfds, to);
- restore_user_sigmask(sigmask, &sigsaved);
-
+ restore_user_sigmask(sigmask, &sigsaved, ret == -EINTR);
/* We can restart this syscall, usually */
if (ret == -EINTR)
ret = -ERESTARTNOHAND;
@@ -1461,8 +1456,7 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds,
ret = do_sys_poll(ufds, nfds, to);
- restore_user_sigmask(sigmask, &sigsaved);
-
+ restore_user_sigmask(sigmask, &sigsaved, ret == -EINTR);
/* We can restart this syscall, usually */
if (ret == -EINTR)
ret = -ERESTARTNOHAND;
diff --git a/include/linux/signal.h b/include/linux/signal.h
index 9702016..78c2bb3 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -276,7 +276,7 @@ extern int sigprocmask(int, sigset_t *, sigset_t *);
extern int set_user_sigmask(const sigset_t __user *usigmask, sigset_t *set,
sigset_t *oldset, size_t sigsetsize);
extern void restore_user_sigmask(const void __user *usigmask,
- sigset_t *sigsaved);
+ sigset_t *sigsaved, bool interrupted);
extern void set_current_blocked(sigset_t *);
extern void __set_current_blocked(const sigset_t *);
extern int show_unhandled_signals;
diff --git a/kernel/signal.c b/kernel/signal.c
index 328a01e..aa6a6f1 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2912,7 +2912,8 @@ EXPORT_SYMBOL(set_compat_user_sigmask);
* This is useful for syscalls such as ppoll, pselect, io_pgetevents and
* epoll_pwait where a new sigmask is passed in from userland for the syscalls.
*/
-void restore_user_sigmask(const void __user *usigmask, sigset_t *sigsaved)
+void restore_user_sigmask(const void __user *usigmask, sigset_t *sigsaved,
+ bool interrupted)
{
if (!usigmask)
@@ -2922,7 +2923,7 @@ void restore_user_sigmask(const void __user *usigmask, sigset_t *sigsaved)
* Restoring sigmask here can lead to delivering signals that the above
* syscalls are intended to block because of the sigmask passed in.
*/
- if (signal_pending(current)) {
+ if (interrupted) {
current->saved_sigmask = *sigsaved;
set_restore_sigmask();
return;
--
2.5.0
next prev parent reply other threads:[~2019-06-04 13:41 UTC|newest]
Thread overview: 123+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-22 3:21 [PATCH v2] signal: Adjust error codes according to restore_user_sigmask() Deepa Dinamani
2019-05-22 15:05 ` Oleg Nesterov
2019-05-22 15:55 ` Deepa Dinamani
2019-05-22 16:14 ` Oleg Nesterov
2019-05-22 16:33 ` Deepa Dinamani
2019-05-23 9:03 ` David Laight
2019-05-23 14:59 ` Oleg Nesterov
2019-05-23 16:18 ` David Laight
2019-05-23 16:36 ` Oleg Nesterov
2019-05-23 16:56 ` David Laight
2019-05-23 18:06 ` Deepa Dinamani
2019-05-23 20:41 ` Deepa Dinamani
2019-05-23 21:06 ` Deepa Dinamani
2019-05-24 9:58 ` David Laight
2019-05-24 14:10 ` Oleg Nesterov
2019-05-24 15:16 ` Deepa Dinamani
2019-05-24 16:33 ` Oleg Nesterov
2019-05-24 17:01 ` Deepa Dinamani
2019-05-27 15:04 ` Oleg Nesterov
2019-05-28 20:47 ` Deepa Dinamani
2019-05-29 16:57 ` Oleg Nesterov
2019-05-29 18:42 ` Deepa Dinamani
2019-05-28 9:02 ` David Laight
2019-05-28 9:12 ` David Laight
2019-05-28 11:37 ` Deepa Dinamani
2019-05-28 12:04 ` David Laight
2019-05-24 14:19 ` Oleg Nesterov
2019-05-24 14:29 ` Deepa Dinamani
2019-05-24 14:51 ` Oleg Nesterov
2019-05-24 13:29 ` Oleg Nesterov
2019-05-24 14:59 ` David Laight
2019-05-24 15:09 ` David Laight
2019-05-24 15:46 ` Oleg Nesterov
2019-05-24 15:44 ` Oleg Nesterov
2019-05-24 16:40 ` David Laight
2019-05-23 14:33 ` Oleg Nesterov
2019-05-22 22:18 ` Chris Down
2019-05-22 22:52 ` Deepa Dinamani
2019-05-29 16:11 ` pselect/etc semantics (Was: [PATCH v2] signal: Adjust error codes according to restore_user_sigmask()) Oleg Nesterov
2019-05-29 16:54 ` David Laight
2019-05-29 18:50 ` Eric Wong
2019-05-30 9:34 ` David Laight
2019-05-30 13:04 ` pselect/etc semantics Eric W. Biederman
2019-05-29 16:56 ` pselect/etc semantics (Was: [PATCH v2] signal: Adjust error codes according to restore_user_sigmask()) Deepa Dinamani
2019-05-29 18:26 ` Deepa Dinamani
2019-05-29 22:32 ` Arnd Bergmann
2019-05-30 1:54 ` pselect/etc semantics Eric W. Biederman
2019-05-30 18:28 ` Arnd Bergmann
2019-05-30 14:40 ` pselect/etc semantics (Was: [PATCH v2] signal: Adjust error codes according to restore_user_sigmask()) Oleg Nesterov
2019-05-30 18:37 ` Arnd Bergmann
2019-05-30 13:01 ` pselect/etc semantics Eric W. Biederman
2019-05-30 15:18 ` David Laight
2019-05-30 16:13 ` Oleg Nesterov
2019-05-30 15:38 ` Eric W. Biederman
2019-05-30 15:48 ` Deepa Dinamani
2019-05-30 16:59 ` Deepa Dinamani
2019-05-30 16:08 ` Oleg Nesterov
2019-05-30 17:20 ` Eric W. Biederman
2019-05-30 16:22 ` David Laight
2019-05-30 15:57 ` Oleg Nesterov
2019-05-30 21:03 ` Eric Wong
2019-06-04 13:41 ` Oleg Nesterov [this message]
2019-06-04 15:31 ` [PATCH] signal: remove the wrong signal_pending() check in restore_user_sigmask() Eric W. Biederman
2019-06-04 15:57 ` David Laight
2019-06-04 16:37 ` Arnd Bergmann
2019-06-04 18:14 ` Deepa Dinamani
2019-06-04 18:35 ` Eric Wong
2019-06-04 21:26 ` Linus Torvalds
2019-06-04 22:24 ` Eric Wong
2019-06-04 23:51 ` Eric W. Biederman
2019-06-05 9:04 ` Oleg Nesterov
2019-06-05 8:56 ` Oleg Nesterov
2019-06-05 9:02 ` David Laight
2019-06-05 9:25 ` Oleg Nesterov
2019-06-05 9:58 ` David Laight
2019-06-05 15:58 ` [PATCH -mm 0/1] signal: simplify set_user_sigmask/restore_user_sigmask Oleg Nesterov
2019-06-05 15:58 ` [PATCH -mm 1/1] " Oleg Nesterov
2019-06-06 0:14 ` kbuild test robot
2019-06-06 1:06 ` kbuild test robot
2019-06-06 7:25 ` Oleg Nesterov
2019-06-06 7:30 ` Sedat Dilek
2019-06-05 17:24 ` [PATCH -mm 0/1] " Linus Torvalds
2019-06-06 9:05 ` David Laight
2019-06-06 11:05 ` Oleg Nesterov
2019-06-06 11:29 ` David Laight
2019-06-06 12:41 ` Oleg Nesterov
2019-06-06 13:23 ` David Laight
2019-06-06 10:22 ` Oleg Nesterov
2019-06-06 11:32 ` [PATCH -mm V2 1/1] " Oleg Nesterov
2019-06-06 14:08 ` [PATCH 0/2] select: simplify the usage of restore_saved_sigmask_unless() Oleg Nesterov
2019-06-06 14:08 ` [PATCH 1/2] select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR Oleg Nesterov
2019-06-07 18:05 ` Linus Torvalds
2019-06-06 14:09 ` [PATCH 2/2] select: shift restore_saved_sigmask_unless() into poll_select_copy_remaining() Oleg Nesterov
2019-06-07 21:39 ` [RFC PATCH 0/5]: Removing saved_sigmask Eric W. Biederman
2019-06-07 21:41 ` [RFC PATCH 1/5] signal: Teach sigsuspend to use set_user_sigmask Eric W. Biederman
2019-06-07 22:07 ` Linus Torvalds
2019-06-10 16:22 ` Oleg Nesterov
2019-06-10 21:20 ` Eric W. Biederman
2019-06-11 9:52 ` David Laight
2019-06-11 11:14 ` David Laight
2019-06-12 12:55 ` Eric W. Biederman
2019-06-12 13:24 ` David Laight
2019-06-12 13:35 ` Oleg Nesterov
2019-06-12 13:39 ` David Laight
2019-06-11 15:46 ` David Laight
2019-06-12 12:40 ` Eric W. Biederman
2019-06-12 13:45 ` Oleg Nesterov
2019-06-12 14:18 ` David Laight
2019-06-12 15:11 ` Eric W. Biederman
2019-06-12 15:37 ` Oleg Nesterov
2019-06-13 8:48 ` David Laight
2019-06-13 9:43 ` Oleg Nesterov
2019-06-13 10:56 ` David Laight
2019-06-13 12:43 ` Oleg Nesterov
2019-06-11 18:55 ` Oleg Nesterov
2019-06-11 19:02 ` Eric W. Biederman
2019-06-12 8:39 ` David Laight
2019-06-12 13:09 ` Eric W. Biederman
2019-06-07 21:41 ` [RFC PATCH 2/5] signal/kvm: Stop using sigprocmask in kvm_sigset_(activate|deactivate) Eric W. Biederman
2019-06-07 21:42 ` [RFC PATCH 3/5] signal: Always keep real_blocked in sync with blocked Eric W. Biederman
2019-06-07 21:43 ` [RFC PATCH 4/5] signal: Remove saved_sigmask Eric W. Biederman
2019-06-07 21:44 ` [RFC PATCH 5/5] signal: Remove the unnecessary restore_sigmask flag Eric W. Biederman
2019-06-11 18:58 ` [RFC PATCH 0/5]: Removing saved_sigmask Oleg Nesterov
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