lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 28 Nov 2022 17:48:43 +0900 From: Masami Hiramatsu (Google) <mhiramat@...nel.org> To: Li Huafei <lihuafei1@...wei.com> Cc: <naveen.n.rao@...ux.ibm.com>, <anil.s.keshavamurthy@...el.com>, <rostedt@...dmis.org>, <linux-kernel@...r.kernel.org> Subject: Re: [PATCH] kprobes: Fix check for probe enabled in kill_kprobe() On Sat, 26 Nov 2022 19:43:16 +0800 Li Huafei <lihuafei1@...wei.com> wrote: > In kill_kprobe(), the check whether disarm_kprobe_ftrace() needs to be > called always fails. This is because before that we set the > KPROBE_FLAG_GONE flag for kprobe so that "!kprobe_disabled(p)" is always > false. Good catch! Acked-by: Masami Hiramatsu (Google) <mhiramat@...nel.org> Thank you! > > The disarm_kprobe_ftrace() call introduced by commit: > > 0cb2f1372baa ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler") > > to fix the NULL pointer reference problem. When the probe is enabled, if > we do not disarm it, this problem still exists. > > Fix it by putting the probe enabled check before setting the > KPROBE_FLAG_GONE flag. > > Fixes: 3031313eb3d54 ("kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()") > Signed-off-by: Li Huafei <lihuafei1@...wei.com> > --- > kernel/kprobes.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 3050631e528d..a35074f0daa1 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -2364,6 +2364,14 @@ static void kill_kprobe(struct kprobe *p) > > lockdep_assert_held(&kprobe_mutex); > > + /* > + * The module is going away. We should disarm the kprobe which > + * is using ftrace, because ftrace framework is still available at > + * 'MODULE_STATE_GOING' notification. > + */ > + if (kprobe_ftrace(p) && !kprobe_disabled(p) && !kprobes_all_disarmed) > + disarm_kprobe_ftrace(p); > + > p->flags |= KPROBE_FLAG_GONE; > if (kprobe_aggrprobe(p)) { > /* > @@ -2380,14 +2388,6 @@ static void kill_kprobe(struct kprobe *p) > * the original probed function (which will be freed soon) any more. > */ > arch_remove_kprobe(p); > - > - /* > - * The module is going away. We should disarm the kprobe which > - * is using ftrace, because ftrace framework is still available at > - * 'MODULE_STATE_GOING' notification. > - */ > - if (kprobe_ftrace(p) && !kprobe_disabled(p) && !kprobes_all_disarmed) > - disarm_kprobe_ftrace(p); > } > > /* Disable one kprobe */ > -- > 2.17.1 > -- Masami Hiramatsu (Google) <mhiramat@...nel.org>
Powered by blists - more mailing lists