From: Oleg Nesterov <oleg@redhat.com>
To: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: srikar@linux.vnet.ibm.com, rostedt@goodmis.org,
mhiramat@kernel.org, liu.song.a23@gmail.com,
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
Subject: Re: [PATCH] Uprobes: Fix kernel oops with delayed_uprobe_remove()
Date: Wed, 14 Nov 2018 17:06:01 +0100 [thread overview]
Message-ID: <20181114160600.GD13885@redhat.com> (raw)
In-Reply-To: <20181114081921.26484-1-ravi.bangoria@linux.ibm.com>
On 11/14, Ravi Bangoria wrote:
>
> 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().
The patch looks good to me, but could you update the changelog?
Please explain that the exiting task calls uprobe_clear_state() which
can race with delayed_uprobe_remove(). IIUC this is the only problem
solved by this patch, right?
Oleg.
WARNING: multiple messages have this Message-ID (diff)
From: oleg@redhat.com (Oleg Nesterov)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] Uprobes: Fix kernel oops with delayed_uprobe_remove()
Date: Wed, 14 Nov 2018 17:06:01 +0100 [thread overview]
Message-ID: <20181114160600.GD13885@redhat.com> (raw)
In-Reply-To: <20181114081921.26484-1-ravi.bangoria@linux.ibm.com>
On 11/14, Ravi Bangoria wrote:
>
> 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().
The patch looks good to me, but could you update the changelog?
Please explain that the exiting task calls uprobe_clear_state() which
can race with delayed_uprobe_remove(). IIUC this is the only problem
solved by this patch, right?
Oleg.
next prev parent reply other threads:[~2018-11-14 16:08 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-14 8:19 [PATCH] Uprobes: Fix kernel oops with delayed_uprobe_remove() Ravi Bangoria
2018-11-14 8:19 ` Ravi Bangoria
2018-11-14 16:06 ` Oleg Nesterov [this message]
2018-11-14 16:06 ` Oleg Nesterov
2018-11-15 4:06 ` Ravi Bangoria
2018-11-15 4:06 ` Ravi Bangoria
2018-11-15 12:43 ` Oleg Nesterov
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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