From: Peter Zijlstra <peterz@infradead.org>
To: mingo@kernel.org
Cc: linux-kernel@vger.kernel.org, acme@kernel.org,
mathieu.desnoyers@efficios.com,
alexander.shishkin@linux.intel.com, dvyukov@google.com,
fweisbec@gmail.com, oleg@redhat.com, peterz@infradead.org,
stable@vger.kernel.org
Subject: [PATCH 2/4] perf: Fix event inheritance on fork()
Date: Thu, 16 Mar 2017 13:47:49 +0100 [thread overview]
Message-ID: <20170316125823.190342547@infradead.org> (raw)
In-Reply-To: 20170316124747.804596354@infradead.org
[-- Attachment #1: peterz-perf-fix-perf_event_init_context.patch --]
[-- Type: text/plain, Size: 1556 bytes --]
While hunting for clues to a use-after-free, Oleg spotted that
perf_event_init_context() can loose an error value with the result
that fork() can succeed even though we did not fully inherit the perf
event context.
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: stable@vger.kernel.org
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Spotted-by: Oleg Nesterov <oleg@redhat.com>
Fixes: 889ff0150661 ("perf/core: Split context's event group list into pinned and non-pinned lists")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
kernel/events/core.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10820,7 +10819,7 @@ static int perf_event_init_context(struc
ret = inherit_task_group(event, parent, parent_ctx,
child, ctxn, &inherited_all);
if (ret)
- break;
+ goto out_unlock;
}
/*
@@ -10836,7 +10835,7 @@ static int perf_event_init_context(struc
ret = inherit_task_group(event, parent, parent_ctx,
child, ctxn, &inherited_all);
if (ret)
- break;
+ goto out_unlock;
}
raw_spin_lock_irqsave(&parent_ctx->lock, flags);
@@ -10864,6 +10863,7 @@ static int perf_event_init_context(struc
}
raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
+out_unlock:
mutex_unlock(&parent_ctx->mutex);
perf_unpin_context(parent_ctx);
next prev parent reply other threads:[~2017-03-16 13:01 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-16 12:47 [PATCH 0/4] perf patches Peter Zijlstra
2017-03-16 12:47 ` [PATCH 1/4] perf: Fix use-after-free in perf_release() Peter Zijlstra
2017-03-16 15:19 ` [tip:perf/urgent] perf/core: " tip-bot for Peter Zijlstra
2017-03-16 12:47 ` Peter Zijlstra [this message]
2017-03-16 15:19 ` [tip:perf/urgent] perf/core: Fix event inheritance on fork() tip-bot for Peter Zijlstra
2017-03-16 12:47 ` [PATCH 3/4] perf: Simplify perf_event_free_task() Peter Zijlstra
2017-03-16 15:20 ` [tip:perf/urgent] perf/core: " tip-bot for Peter Zijlstra
2017-03-16 12:47 ` [PATCH 4/4] perf: Better explain the inherit magic Peter Zijlstra
2017-03-16 15:21 ` [tip:perf/urgent] perf/core: " tip-bot for Peter Zijlstra
2017-03-16 13:20 ` [PATCH 0/4] perf patches Ingo Molnar
-- strict thread matches above, loose matches on Subject: below --
2017-03-06 9:57 perf: use-after-free in perf_release Dmitry Vyukov
2017-03-06 12:13 ` Peter Zijlstra
2017-03-06 12:17 ` Dmitry Vyukov
2017-03-06 12:23 ` Peter Zijlstra
2017-03-06 12:27 ` Dmitry Vyukov
2017-03-06 12:47 ` Peter Zijlstra
2017-03-06 13:14 ` Peter Zijlstra
2017-03-06 13:34 ` Dmitry Vyukov
2017-03-07 9:08 ` Peter Zijlstra
2017-03-07 9:26 ` Dmitry Vyukov
2017-03-07 9:37 ` Peter Zijlstra
2017-03-07 9:43 ` Dmitry Vyukov
2017-03-07 10:00 ` Peter Zijlstra
2017-03-07 13:16 ` Peter Zijlstra
2017-03-07 13:27 ` Peter Zijlstra
2017-03-07 14:04 ` Oleg Nesterov
2017-03-07 14:17 ` Dmitry Vyukov
2017-03-07 16:51 ` Oleg Nesterov
2017-03-07 17:29 ` Peter Zijlstra
2017-03-14 12:55 ` Peter Zijlstra
2017-03-14 13:24 ` Oleg Nesterov
2017-03-14 13:47 ` Peter Zijlstra
2017-03-14 14:03 ` Oleg Nesterov
2017-03-14 14:07 ` Peter Zijlstra
2017-03-14 14:30 ` Oleg Nesterov
2017-03-14 15:02 ` Peter Zijlstra
2017-03-14 15:07 ` Peter Zijlstra
2017-03-14 15:37 ` Oleg Nesterov
2017-03-14 15:46 ` Peter Zijlstra
2017-03-14 15:19 ` Oleg Nesterov
2017-03-14 15:26 ` Peter Zijlstra
2017-03-14 15:59 ` Peter Zijlstra
2017-03-15 16:43 ` Oleg Nesterov
2017-03-16 12:05 ` Peter Zijlstra
2017-03-16 13:57 ` Peter Zijlstra
2017-03-16 16:41 ` Oleg Nesterov
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