lkml.org 
[lkml]   [2020]   [Jun]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.14 132/136] kprobes: Fix to protect kick_kprobe_optimizer() by kprobe_mutex
    Date
    From: Masami Hiramatsu <mhiramat@kernel.org>

    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 <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>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    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 */

    \
     
     \ /
      Last update: 2020-06-23 22:49    [W:4.062 / U:0.376 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site