From: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
To: srikar@linux.vnet.ibm.com, oleg@redhat.com, rostedt@goodmis.org,
mhiramat@kernel.org, liu.song.a23@gmail.com
Cc: peterz@infradead.org, mingo@redhat.com, acme@kernel.org,
alexander.shishkin@linux.intel.com, jolsa@redhat.com,
namhyung@kernel.org, linux-kernel@vger.kernel.org,
ananth@linux.vnet.ibm.com, alexis.berlemont@gmail.com,
naveen.n.rao@linux.vnet.ibm.com,
linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org,
linux@armlinux.org.uk, ralf@linux-mips.org, paul.burton@mips.com,
Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Subject: [PATCH] Uprobes: Fix kernel oops with delayed_uprobe_remove()
Date: Wed, 14 Nov 2018 13:49:21 +0530 [thread overview]
Message-ID: <20181114081921.26484-1-ravi.bangoria@linux.ibm.com> (raw)
syzbot reported a kernel crash with delayed_uprobe_remove():
https://lkml.org/lkml/2018/11/1/1244
Backtrace mentioned in the link points to a race between process
exit and uprobe_unregister(). Fix it by locking delayed_uprobe_lock
before calling delayed_uprobe_remove() from put_uprobe().
Reported-by: syzbot+cb1fb754b771caca0a88@syzkaller.appspotmail.com
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
---
kernel/events/uprobes.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 96fb51f3994f..e527c4753d4f 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -572,7 +572,9 @@ static void put_uprobe(struct uprobe *uprobe)
* gets called, we don't get a chance to remove uprobe from
* delayed_uprobe_list from remove_breakpoint(). Do it here.
*/
+ mutex_lock(&delayed_uprobe_lock);
delayed_uprobe_remove(uprobe, NULL);
+ mutex_unlock(&delayed_uprobe_lock);
kfree(uprobe);
}
}
--
2.19.1
next reply other threads:[~2018-11-14 8:19 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-14 8:19 Ravi Bangoria [this message]
2018-11-14 16:06 ` [PATCH] Uprobes: Fix kernel oops with delayed_uprobe_remove() Oleg Nesterov
2018-11-15 4:06 ` Ravi Bangoria
2018-11-15 12:43 ` Oleg Nesterov
2018-12-03 6:22 ` Ravi Bangoria
2018-12-04 5:58 ` Steven Rostedt
2018-12-05 3:34 ` [PATCH v2] " Ravi Bangoria
2018-12-05 10:01 ` Srikar Dronamraju
2018-12-05 14:39 ` Oleg Nesterov
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