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authorMarcel Holtmann <marcel@holtmann.org>2013-11-02 13:36:31 +0400
committerGustavo Padovan <gustavo.padovan@collabora.co.uk>2013-11-13 17:36:52 +0400
commit60c7a3c9c77239d5a7430c42a2c796881716cca1 (patch)
treef732c6cd41c97e19b44f7ced0e07194389329012 /net/bluetooth/rfcomm
parent8ce9beac4661f576ea0d518b9f086bb52a171a37 (diff)
downloadlinux-60c7a3c9c77239d5a7430c42a2c796881716cca1.tar.xz
Bluetooth: Fix issue with RFCOMM getsockopt operation
The commit 94a86df01082557e2de45865e538d7fb6c46231c 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 8c1d787be4b62d2d1b6f04953eca4bcf7c839d44 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>
Diffstat (limited to 'net/bluetooth/rfcomm')
-rw-r--r--net/bluetooth/rfcomm/sock.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 30b3721dc6d7..7096cfe3bd5a 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -732,8 +732,9 @@ static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname, c
static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __user *optval, int __user *optlen)
{
struct sock *sk = sock->sk;
+ struct sock *l2cap_sk;
+ struct l2cap_conn *conn;
struct rfcomm_conninfo cinfo;
- struct l2cap_conn *conn = l2cap_pi(sk)->chan->conn;
int len, err = 0;
u32 opt;
@@ -776,6 +777,9 @@ static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __u
break;
}
+ l2cap_sk = rfcomm_pi(sk)->dlc->session->sock->sk;
+ conn = l2cap_pi(l2cap_sk)->chan->conn;
+
memset(&cinfo, 0, sizeof(cinfo));
cinfo.hci_handle = conn->hcon->handle;
memcpy(cinfo.dev_class, conn->hcon->dev_class, 3);