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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.


  reply	other threads:[~2018-11-14 16:06 UTC|newest]

Thread overview: 9+ 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 16:06 ` Oleg Nesterov [this message]
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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