linux/net
Marcel Holtmann 60c7a3c9c7 Bluetooth: Fix issue with RFCOMM getsockopt operation
The commit 94a86df010 seem to have
uncovered a long standing bug that did not trigger so far.

BUG: unable to handle kernel paging request at 00000009dd503502
IP: [<ffffffff815b1868>] rfcomm_sock_getsockopt+0x128/0x200
PGD 0
Oops: 0000 [#1] SMP
Modules linked in: ath5k ath mac80211 cfg80211
CPU: 2 PID: 1459 Comm: bluetoothd Not tainted 3.11.0-133163-gcebd830 #2
Hardware name: System manufacturer System Product Name/P6T DELUXE V2, BIOS
1202    12/22/2010
task: ffff8803304106a0 ti: ffff88033046a000 task.ti: ffff88033046a000
RIP: 0010:[<ffffffff815b1868>]  [<ffffffff815b1868>]
rfcomm_sock_getsockopt+0x128/0x200
RSP: 0018:ffff88033046bed8  EFLAGS: 00010246
RAX: 00000009dd503502 RBX: 0000000000000003 RCX: 00007fffa2ed5548
RDX: 0000000000000003 RSI: 0000000000000012 RDI: ffff88032fd37480
RBP: ffff88033046bf28 R08: 00007fffa2ed554c R09: ffff88032f5707d8
R10: 00007fffa2ed5548 R11: 0000000000000202 R12: ffff880330bbd000
R13: 00007fffa2ed5548 R14: 0000000000000003 R15: 00007fffa2ed554c
FS:  00007fc44cfac700(0000) GS:ffff88033fc80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000009dd503502 CR3: 00000003304c2000 CR4: 00000000000007e0
Stack:
ffff88033046bf28 ffffffff815b0f2f ffff88033046bf18 0002ffff81105ef6
0000000600000000 ffff88032fd37480 0000000000000012 00007fffa2ed5548
0000000000000003 00007fffa2ed554c ffff88033046bf78 ffffffff814c0380
Call Trace:
[<ffffffff815b0f2f>] ? rfcomm_sock_setsockopt+0x5f/0x190
[<ffffffff814c0380>] SyS_getsockopt+0x60/0xb0
[<ffffffff815e0852>] system_call_fastpath+0x16/0x1b
Code: 02 00 00 00 0f 47 d0 4c 89 ef e8 74 13 cd ff 83 f8 01 19 c9 f7 d1 83 e1
f2 e9 4b ff ff ff 0f 1f 44 00 00 49 8b 84 24 70 02 00 00 <4c> 8b 30 4c 89 c0 e8
2d 19 cd ff 85 c0 49 89 d7 b9 f2 ff ff ff
RIP  [<ffffffff815b1868>] rfcomm_sock_getsockopt+0x128/0x200
RSP <ffff88033046bed8>
CR2: 00000009dd503502

It triggers in the following segment of the code:

0x1313 is in rfcomm_sock_getsockopt (net/bluetooth/rfcomm/sock.c:743).
738
739	static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __user *optval, int __user *optlen)
740	{
741		struct sock *sk = sock->sk;
742		struct rfcomm_conninfo cinfo;
743		struct l2cap_conn *conn = l2cap_pi(sk)->chan->conn;
744		int len, err = 0;
745		u32 opt;
746
747		BT_DBG("sk %p", sk);

The l2cap_pi(sk) is wrong here since it should have been rfcomm_pi(sk),
but that socket of course does not contain the low-level connection
details requested here.

Tracking down the actual offending commit, it seems that this has been
introduced when doing some L2CAP refactoring:

commit 8c1d787be4
Author: Gustavo F. Padovan <padovan@profusion.mobi>
Date:   Wed Apr 13 20:23:55 2011 -0300

@@ -743,6 +743,7 @@ static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __u
        struct sock *sk = sock->sk;
        struct sock *l2cap_sk;
        struct rfcomm_conninfo cinfo;
+       struct l2cap_conn *conn = l2cap_pi(sk)->chan->conn;
        int len, err = 0;
        u32 opt;

@@ -787,8 +788,8 @@ static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __u

                l2cap_sk = rfcomm_pi(sk)->dlc->session->sock->sk;

-               cinfo.hci_handle = l2cap_pi(l2cap_sk)->conn->hcon->handle;
-               memcpy(cinfo.dev_class, l2cap_pi(l2cap_sk)->conn->hcon->dev_class, 3);
+               cinfo.hci_handle = conn->hcon->handle;
+               memcpy(cinfo.dev_class, conn->hcon->dev_class, 3);

The l2cap_sk got accidentally mixed into the sk (which is RFCOMM) and
now causing a problem within getsocketopt() system call. To fix this,
just re-introduce l2cap_sk and make sure the right socket is used for
the low-level connection details.

Reported-by: Fabio Rossi <rossi.f@inwind.it>
Reported-by: Janusz Dziedzic <janusz.dziedzic@gmail.com>
Tested-by: Janusz Dziedzic <janusz.dziedzic@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
2013-11-13 11:36:52 -02:00
..
9p for-linus-3.12-merge minor 9p fixes and tweaks for 3.12 merge window 2013-09-11 12:34:13 -07:00
802 net/802/mrp: fix lockdep splat 2013-05-14 13:02:30 -07:00
8021q net: vlan: inherit addr_assign_type along with dev_addr 2013-09-03 20:57:49 -04:00
appletalk net: proc_fs: trivial: print UIDs as unsigned int 2013-08-15 14:37:46 -07:00
atm net: always pass struct netdev_notifier_info to netdevice notifiers 2013-05-28 21:58:54 -07:00
ax25 net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
batman-adv batman-adv: set the TAG flag for the vid passed to BLA 2013-09-17 21:15:16 +02:00
bluetooth Bluetooth: Fix issue with RFCOMM getsockopt operation 2013-11-13 11:36:52 -02:00
bridge bridge: fix NULL pointer deref of br_port_get_rcu 2013-09-15 22:03:33 -04:00
caif caif: Add missing braces to multiline if in cfctrl_linkup_request 2013-09-05 14:31:02 -04:00
can can: gw: add a per rule limitation of frame hops 2013-08-29 22:58:24 +02:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2013-09-19 12:50:37 -05:00
core netpoll: fix NULL pointer dereference in netpoll_cleanup 2013-09-19 14:15:53 -04:00
dcb rtnetlink: Remove passing of attributes into rtnl_doit functions 2013-03-22 10:31:16 -04:00
dccp net:dccp: do not report ICMP redirects to user space 2013-09-18 12:33:44 -04:00
decnet net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
dns_resolver net: strict_strtoul is obsolete, use kstrtoul instead 2013-07-12 16:09:14 -07:00
dsa net: dsa: inherit addr_assign_type along with dev_addr 2013-09-03 20:57:49 -04:00
ethernet net: Fix sysfs_format_mac() code duplication. 2013-07-16 17:09:22 -07:00
ieee802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-09-05 14:54:29 -07:00
ipv4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-09-19 13:57:28 -05:00
ipv6 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2013-09-17 20:22:53 -04:00
ipx net: proc_fs: trivial: print UIDs as unsigned int 2013-08-15 14:37:46 -07:00
irda net/irda: fixed style issues in irttp 2013-07-19 17:34:40 -07:00
iucv net: delete __cpuinit usage from all net files 2013-07-14 19:36:58 -04:00
key xfrm: Remove rebundant address family checking 2013-08-07 10:12:58 +02:00
l2tp l2tp: make datapath resilient to packet loss when sequence numbers enabled 2013-07-02 16:33:25 -07:00
lapb
llc llc: Use normal etherdevice.h tests 2013-09-03 22:34:47 -04:00
mac80211 mac80211: disable WMM with invalid parameters 2013-10-17 15:38:22 +02:00
mac802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-04-30 03:55:20 -04:00
mpls MPLS: Add limited GSO support 2013-05-27 22:50:59 -07:00
netfilter ip: generate unique IP identificator if local fragmentation is allowed 2013-09-19 14:11:15 -04:00
netlabel netlabel: use domain based selectors when address based selectors are not available 2013-08-02 16:57:01 -07:00
netlink net: netlink: filter particular protocols from analyzers 2013-09-06 14:43:48 -04:00
netrom net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
nfc NFC: Update secure element state 2013-08-14 01:13:40 +02:00
openvswitch net: ovs: flow: fix potential illegal memory access in __parse_flow_nlattrs 2013-09-11 16:09:58 -04:00
packet net: packet: use reciprocal_divide in fanout_demux_hash 2013-08-29 16:43:29 -04:00
phonet net: proc_fs: trivial: print UIDs as unsigned int 2013-08-15 14:37:46 -07:00
rds net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
rfkill Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-09-05 14:54:29 -07:00
rose net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
rxrpc
sched net_sched: htb: fix a typo in htb_change_class() 2013-09-11 17:16:22 -04:00
sctp net: sctp: rfc4443: do not report ICMP redirects to user space 2013-09-16 21:40:15 -04:00
sunrpc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-09-12 15:01:38 -07:00
tipc tipc: set sk_err correctly when connection fails 2013-08-30 16:06:57 -04:00
unix af_unix: fix bug on large send() 2013-08-11 22:02:36 -07:00
vmw_vsock Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-08-16 15:37:26 -07:00
wimax
wireless wireless: radiotap: fix parsing buffer overrun 2013-10-14 09:47:00 +02:00
x25 x25: add a sanity check parsing X.25 facilities 2013-09-04 00:27:27 -04:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-09-05 14:58:52 -04:00
compat.c net: Unbreak compat_sys_{send,recv}msg 2013-06-06 11:52:14 -07:00
Kconfig Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
Makefile MPLS: Add limited GSO support 2013-05-27 22:50:59 -07:00
nonet.c
socket.c Merge git://git.kvack.org/~bcrl/aio-next 2013-09-13 10:55:58 -07:00
sysctl_net.c