From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>,
syzbot+a1c743815982d9496393@syzkaller.appspotmail.com,
Anmol Karn <anmol.karan123@gmail.com>
Subject: [PATCH 4.14 02/20] rose: Fix Null pointer dereference in rose_send_frame()
Date: Sun, 6 Dec 2020 12:17:05 +0100 [thread overview]
Message-ID: <20201206111555.683328733@linuxfoundation.org> (raw)
In-Reply-To: <20201206111555.569713359@linuxfoundation.org>
From: Anmol Karn <anmol.karan123@gmail.com>
[ Upstream commit 3b3fd068c56e3fbea30090859216a368398e39bf ]
rose_send_frame() dereferences `neigh->dev` when called from
rose_transmit_clear_request(), and the first occurrence of the
`neigh` is in rose_loopback_timer() as `rose_loopback_neigh`,
and it is initialized in rose_add_loopback_neigh() as NULL.
i.e when `rose_loopback_neigh` used in rose_loopback_timer()
its `->dev` was still NULL and rose_loopback_timer() was calling
rose_rx_call_request() without checking for NULL.
- net/rose/rose_link.c
This bug seems to get triggered in this line:
rose_call = (ax25_address *)neigh->dev->dev_addr;
Fix it by adding NULL checking for `rose_loopback_neigh->dev`
in rose_loopback_timer().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Reported-by: syzbot+a1c743815982d9496393@syzkaller.appspotmail.com
Tested-by: syzbot+a1c743815982d9496393@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=9d2a7ca8c7f2e4b682c97578dfa3f236258300b3
Signed-off-by: Anmol Karn <anmol.karan123@gmail.com>
Link: https://lore.kernel.org/r/20201119191043.28813-1-anmol.karan123@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/rose/rose_loopback.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
--- a/net/rose/rose_loopback.c
+++ b/net/rose/rose_loopback.c
@@ -99,10 +99,19 @@ static void rose_loopback_timer(struct t
}
if (frametype == ROSE_CALL_REQUEST) {
- if ((dev = rose_dev_get(dest)) != NULL) {
- if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0)
- kfree_skb(skb);
- } else {
+ if (!rose_loopback_neigh->dev) {
+ kfree_skb(skb);
+ continue;
+ }
+
+ dev = rose_dev_get(dest);
+ if (!dev) {
+ kfree_skb(skb);
+ continue;
+ }
+
+ if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) {
+ dev_put(dev);
kfree_skb(skb);
}
} else {
next prev parent reply other threads:[~2020-12-06 11:38 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-06 11:17 [PATCH 4.14 00/20] 4.14.211-rc1 review Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 01/20] net/af_iucv: set correct sk_protocol for child sockets Greg Kroah-Hartman
2020-12-06 11:17 ` Greg Kroah-Hartman [this message]
2020-12-06 11:17 ` [PATCH 4.14 03/20] sock: set sk_err to ee_errno on dequeue from errq Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 04/20] tcp: Set INET_ECN_xmit configuration in tcp_reinit_congestion_control Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 05/20] tun: honor IOCB_NOWAIT flag Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 06/20] usbnet: ipheth: fix connectivity with iOS 14 Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 07/20] bonding: wait for sysfs kobject destruction before freeing struct slave Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 08/20] netfilter: bridge: reset skb->pkt_type after NF_INET_POST_ROUTING traversal Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 09/20] ipv4: Fix tos mask in inet_rtm_getroute() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 10/20] ibmvnic: Ensure that SCRQ entry reads are correctly ordered Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 11/20] ibmvnic: Fix TX completion error handling Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 12/20] net/x25: prevent a couple of overflows Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 13/20] cxgb3: fix error return code in t3_sge_alloc_qset() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 14/20] net: pasemi: fix error return code in pasemi_mac_open() Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 15/20] net/mlx5: Fix wrong address reclaim when command interface is down Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 16/20] dt-bindings: net: correct interrupt flags in examples Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 17/20] ALSA: usb-audio: US16x08: fix value count for level meters Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 18/20] Input: xpad - support Ardwiino Controllers Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 19/20] Input: i8042 - add ByteSpeed touchpad to noloop table Greg Kroah-Hartman
2020-12-06 11:17 ` [PATCH 4.14 20/20] RDMA/i40iw: Address an mmap handler exploit in i40iw Greg Kroah-Hartman
2020-12-07 10:04 ` [PATCH 4.14 00/20] 4.14.211-rc1 review Naresh Kamboju
2020-12-07 15:54 ` Guenter Roeck
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