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authorMasami Hiramatsu <mhiramat@kernel.org>2020-05-12 17:02:56 +0900
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2020-06-16 21:21:01 -0400
commit1a0aa991a6274161c95a844c58cfb801d681eb59 (patch)
treea90f727b5b0b1406ffbc7ae50cc90ec1c0bb4f2e /kernel
parent7e6a71d8e60187726e29b13d9e9b23b77026c17a (diff)
downloadlinux-1a0aa991a6274161c95a844c58cfb801d681eb59.tar.gz
kprobes: Fix to protect kick_kprobe_optimizer() by kprobe_mutex
In kprobe_optimizer() kick_kprobe_optimizer() is called
without kprobe_mutex, but this can race with other caller
which is protected by kprobe_mutex.

To fix that, expand kprobe_mutex protected area to protect
kick_kprobe_optimizer() call.

Link: http://lkml.kernel.org/r/158927057586.27680.5036330063955940456.stgit@devnote2

Fixes: cd7ebe2298ff ("kprobes: Use text_poke_smp_batch for optimizing")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ziqian SUN <zsun@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kprobes.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index ceb0e273bd69..0e185763578b 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -592,11 +592,12 @@ static void kprobe_optimizer(struct work_struct *work)
 	mutex_unlock(&module_mutex);
 	mutex_unlock(&text_mutex);
 	cpus_read_unlock();
-	mutex_unlock(&kprobe_mutex);
 
 	/* Step 5: Kick optimizer again if needed */
 	if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list))
 		kick_kprobe_optimizer();
+
+	mutex_unlock(&kprobe_mutex);
 }
 
 /* Wait for completing optimization and unoptimization */