From: Masami Hiramatsu <[email protected]> commit 1a0aa991a6274161c95a844c58cfb801d681eb59 upstream.
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 <[email protected]> Cc: "Gustavo A . R . Silva" <[email protected]> Cc: Anders Roxell <[email protected]> Cc: "Naveen N . Rao" <[email protected]> Cc: Anil S Keshavamurthy <[email protected]> Cc: David Miller <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ziqian SUN <[email protected]> Cc: [email protected] Signed-off-by: Masami Hiramatsu <[email protected]> Signed-off-by: Steven Rostedt (VMware) <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- kernel/kprobes.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -599,11 +599,12 @@ static void kprobe_optimizer(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 */
