From: Anmol Karn <anmol.karan123@gmail.com>
To: marcel@holtmann.org, johan.hedberg@gmail.com
Cc: netdev@vger.kernel.org,
syzbot+0bef568258653cff272f@syzkaller.appspotmail.com,
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: [Linux-kernel-mentees] [PATCH] net: bluetooth: Fix null pointer dereference in hci_event_packet()
Date: Wed, 30 Sep 2020 19:48:13 +0530 [thread overview]
Message-ID: <20200930141813.410209-1-anmol.karan123@gmail.com> (raw)
In-Reply-To: <20200929173231.396261-1-anmol.karan123@gmail.com>
AMP_MGR is getting derefernced in hci_phy_link_complete_evt(), when called from hci_event_packet() and there is a possibility, that hcon->amp_mgr may not be found when accessing after initialization of hcon.
- net/bluetooth/hci_event.c:4945
The bug seems to get triggered in this line:
bredr_hcon = hcon->amp_mgr->l2cap_conn->hcon;
Fix it by adding a NULL check for the hcon->amp_mgr before checking the ev-status.
Fixes: d5e911928bd8 ("Bluetooth: AMP: Process Physical Link Complete evt")
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>
---
Change in v3:
- changed return o; to return; (Reported-by: kernel test robot <lkp@intel.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..bbe0ca42cad2 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 (!hcon->amp_mgr) {
+ hci_dev_unlock(hdev);
+ return;
+ }
+
if (ev->status) {
hci_conn_del(hcon);
hci_dev_unlock(hdev);
--
2.28.0
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next prev parent reply other threads:[~2020-09-30 14:18 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
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 [this message]
2020-10-01 7:06 ` Marcel Holtmann
2020-10-01 7:45 ` Anmol Karn
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