From: Eric Biggers <ebiggers@kernel.org>
To: Anmol Karn <anmol.karan123@gmail.com>
Cc: syzbot+0bef568258653cff272f@syzkaller.appspotmail.com,
johan.hedberg@gmail.com, netdev@vger.kernel.org,
marcel@holtmann.org, syzkaller-bugs@googlegroups.com,
linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org,
kuba@kernel.org, linux-kernel-mentees@lists.linuxfoundation.org,
davem@davemloft.net
Subject: Re: [Linux-kernel-mentees] [PATCH] net: bluetooth: Fix null pointer dereference in hci_event_packet()
Date: Wed, 9 Sep 2020 22:06:59 -0700 [thread overview]
Message-ID: <20200910050659.GD828@sol.localdomain> (raw)
In-Reply-To: <20200910043424.19894-1-anmol.karan123@gmail.com>
On Thu, Sep 10, 2020 at 10:04:24AM +0530, Anmol Karn wrote:
> Prevent hci_phy_link_complete_evt() from dereferencing 'hcon->amp_mgr'
> as NULL. Fix it by adding pointer check for it.
>
> Reported-and-tested-by: syzbot+0bef568258653cff272f@syzkaller.appspotmail.com
> Link: https://syzkaller.appspot.com/bug?extid=0bef568258653cff272f
> Signed-off-by: Anmol Karn <anmol.karan123@gmail.com>
> ---
> net/bluetooth/hci_event.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 4b7fc430793c..871e16804433 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -4936,6 +4936,11 @@ static void hci_phy_link_complete_evt(struct hci_dev *hdev,
> return;
> }
>
> + if (IS_ERR_OR_NULL(hcon->amp_mgr)) {
> + hci_dev_unlock(hdev);
> + return;
> + }
> +
In patches that fix a NULL pointer dereference, please include a brief
explanation of why the pointer can be NULL, including what it means
semantically; and why the proposed change is the best fix for the problem.
Also, why IS_ERR_OR_NULL()?
- Eric
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next prev parent reply other threads:[~2020-09-10 5:07 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-10 4:34 [Linux-kernel-mentees] [PATCH] net: bluetooth: Fix null pointer dereference in hci_event_packet() Anmol Karn
2020-09-10 5:06 ` Eric Biggers [this message]
2020-09-10 6:02 ` Anmol Karn
2020-09-10 10:49 ` Dan Carpenter
2020-09-10 14:58 ` Anmol Karn
2020-09-12 9:10 ` Anmol Karn
2020-09-14 15:44 ` Dan Carpenter
2020-09-14 18:37 ` Anmol Karn
2020-09-29 17:32 ` Anmol Karn
2020-09-30 14:18 ` Anmol Karn
2020-10-01 7:06 ` Marcel Holtmann
2020-10-01 7:45 ` Anmol Karn
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