On Tue, Jun 23, 2020 at 01:57:26PM +0200, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1a0aa991a6274161c95a844c58cfb801d681eb59 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu mhiramat@kernel.org Date: Tue, 12 May 2020 17:02:56 +0900 Subject: [PATCH] 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@devnot...
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
The conflict happened because we don't have 2d1e38f56622 ("kprobes: Cure hotplug lock ordering issues") on 4.9 and 4.4. I've fixed it up and queued for both branches.