diff mbox series

Bluetooth: check for zapped sk before connecting

Message ID 20210322140046.1.I6c4306f6e8ba3ccc9106067d4eb70092f8cb2a49@changeid (mailing list archive)
State New, archived
Headers show
Series Bluetooth: check for zapped sk before connecting | expand

Commit Message

Archie Pusaka March 22, 2021, 6:01 a.m. UTC
From: Archie Pusaka <apusaka@chromium.org>

There is a possibility of receiving a zapped sock on
l2cap_sock_connect(). This could lead to interesting crashes, one
such case is tearing down an already tore l2cap_sock as is happened
with this call trace:

__dump_stack lib/dump_stack.c:15 [inline]
dump_stack+0xc4/0x118 lib/dump_stack.c:56
register_lock_class kernel/locking/lockdep.c:792 [inline]
register_lock_class+0x239/0x6f6 kernel/locking/lockdep.c:742
__lock_acquire+0x209/0x1e27 kernel/locking/lockdep.c:3105
lock_acquire+0x29c/0x2fb kernel/locking/lockdep.c:3599
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:137 [inline]
_raw_spin_lock_bh+0x38/0x47 kernel/locking/spinlock.c:175
spin_lock_bh include/linux/spinlock.h:307 [inline]
lock_sock_nested+0x44/0xfa net/core/sock.c:2518
l2cap_sock_teardown_cb+0x88/0x2fb net/bluetooth/l2cap_sock.c:1345
l2cap_chan_del+0xa3/0x383 net/bluetooth/l2cap_core.c:598
l2cap_chan_close+0x537/0x5dd net/bluetooth/l2cap_core.c:756
l2cap_chan_timeout+0x104/0x17e net/bluetooth/l2cap_core.c:429
process_one_work+0x7e3/0xcb0 kernel/workqueue.c:2064
worker_thread+0x5a5/0x773 kernel/workqueue.c:2196
kthread+0x291/0x2a6 kernel/kthread.c:211
ret_from_fork+0x4e/0x80 arch/x86/entry/entry_64.S:604

Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reported-by: syzbot+abfc0f5e668d4099af73@syzkaller.appspotmail.com
Reviewed-by: Alain Michaud <alainm@chromium.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
---

 net/bluetooth/l2cap_sock.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

bluez.test.bot@gmail.com March 22, 2021, 7:33 a.m. UTC | #1
This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=452547

---Test result---

##############################
Test: CheckPatch - PASS


##############################
Test: CheckGitLint - PASS


##############################
Test: CheckBuildK - PASS


##############################
Test: CheckTestRunner: Setup - PASS


##############################
Test: CheckTestRunner: l2cap-tester - PASS
Total: 40, Passed: 34 (85.0%), Failed: 0, Not Run: 6

##############################
Test: CheckTestRunner: bnep-tester - PASS
Total: 1, Passed: 1 (100.0%), Failed: 0, Not Run: 0

##############################
Test: CheckTestRunner: mgmt-tester - PASS
Total: 416, Passed: 402 (96.6%), Failed: 0, Not Run: 14

##############################
Test: CheckTestRunner: rfcomm-tester - PASS
Total: 9, Passed: 9 (100.0%), Failed: 0, Not Run: 0

##############################
Test: CheckTestRunner: sco-tester - PASS
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0

##############################
Test: CheckTestRunner: smp-tester - PASS
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0

##############################
Test: CheckTestRunner: userchan-tester - PASS
Total: 3, Passed: 3 (100.0%), Failed: 0, Not Run: 0



---
Regards,
Linux Bluetooth
Marcel Holtmann March 22, 2021, 3:53 p.m. UTC | #2
Hi Archie,

> There is a possibility of receiving a zapped sock on
> l2cap_sock_connect(). This could lead to interesting crashes, one
> such case is tearing down an already tore l2cap_sock as is happened
> with this call trace:
> 
> __dump_stack lib/dump_stack.c:15 [inline]
> dump_stack+0xc4/0x118 lib/dump_stack.c:56
> register_lock_class kernel/locking/lockdep.c:792 [inline]
> register_lock_class+0x239/0x6f6 kernel/locking/lockdep.c:742
> __lock_acquire+0x209/0x1e27 kernel/locking/lockdep.c:3105
> lock_acquire+0x29c/0x2fb kernel/locking/lockdep.c:3599
> __raw_spin_lock_bh include/linux/spinlock_api_smp.h:137 [inline]
> _raw_spin_lock_bh+0x38/0x47 kernel/locking/spinlock.c:175
> spin_lock_bh include/linux/spinlock.h:307 [inline]
> lock_sock_nested+0x44/0xfa net/core/sock.c:2518
> l2cap_sock_teardown_cb+0x88/0x2fb net/bluetooth/l2cap_sock.c:1345
> l2cap_chan_del+0xa3/0x383 net/bluetooth/l2cap_core.c:598
> l2cap_chan_close+0x537/0x5dd net/bluetooth/l2cap_core.c:756
> l2cap_chan_timeout+0x104/0x17e net/bluetooth/l2cap_core.c:429
> process_one_work+0x7e3/0xcb0 kernel/workqueue.c:2064
> worker_thread+0x5a5/0x773 kernel/workqueue.c:2196
> kthread+0x291/0x2a6 kernel/kthread.c:211
> ret_from_fork+0x4e/0x80 arch/x86/entry/entry_64.S:604
> 
> Signed-off-by: Archie Pusaka <apusaka@chromium.org>
> Reported-by: syzbot+abfc0f5e668d4099af73@syzkaller.appspotmail.com
> Reviewed-by: Alain Michaud <alainm@chromium.org>
> Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> Reviewed-by: Guenter Roeck <groeck@chromium.org>
> ---
> 
> net/bluetooth/l2cap_sock.c | 7 +++++++
> 1 file changed, 7 insertions(+)
> 
> diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
> index f1b1edd0b697..b86fd8cc4dc1 100644
> --- a/net/bluetooth/l2cap_sock.c
> +++ b/net/bluetooth/l2cap_sock.c
> @@ -182,6 +182,13 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr,
> 
> 	BT_DBG("sk %p", sk);
> 
> +	lock_sock(sk);
> +	if (sock_flag(sk, SOCK_ZAPPED)) {
> +		release_sock(sk);
> +		return -EINVAL;
> +	}
> +	release_sock(sk);
> +

hmmm. I wonder if this would look better and easy to see that the locking is done correctly.

	lock_sock(sk);
	zapped = sock_flag(sk, SOCK_ZAPPED);
	release_sock(sk);

	if (zapped)
		return -EINVAL;

Regards

Marcel
Archie Pusaka March 23, 2021, 8:42 a.m. UTC | #3
Hi Marcel,

Thanks for your suggestion. I implemented it in v2, please take another look.


On Mon, 22 Mar 2021 at 23:53, Marcel Holtmann <marcel@holtmann.org> wrote:
>
> Hi Archie,
>
> > There is a possibility of receiving a zapped sock on
> > l2cap_sock_connect(). This could lead to interesting crashes, one
> > such case is tearing down an already tore l2cap_sock as is happened
> > with this call trace:
> >
> > __dump_stack lib/dump_stack.c:15 [inline]
> > dump_stack+0xc4/0x118 lib/dump_stack.c:56
> > register_lock_class kernel/locking/lockdep.c:792 [inline]
> > register_lock_class+0x239/0x6f6 kernel/locking/lockdep.c:742
> > __lock_acquire+0x209/0x1e27 kernel/locking/lockdep.c:3105
> > lock_acquire+0x29c/0x2fb kernel/locking/lockdep.c:3599
> > __raw_spin_lock_bh include/linux/spinlock_api_smp.h:137 [inline]
> > _raw_spin_lock_bh+0x38/0x47 kernel/locking/spinlock.c:175
> > spin_lock_bh include/linux/spinlock.h:307 [inline]
> > lock_sock_nested+0x44/0xfa net/core/sock.c:2518
> > l2cap_sock_teardown_cb+0x88/0x2fb net/bluetooth/l2cap_sock.c:1345
> > l2cap_chan_del+0xa3/0x383 net/bluetooth/l2cap_core.c:598
> > l2cap_chan_close+0x537/0x5dd net/bluetooth/l2cap_core.c:756
> > l2cap_chan_timeout+0x104/0x17e net/bluetooth/l2cap_core.c:429
> > process_one_work+0x7e3/0xcb0 kernel/workqueue.c:2064
> > worker_thread+0x5a5/0x773 kernel/workqueue.c:2196
> > kthread+0x291/0x2a6 kernel/kthread.c:211
> > ret_from_fork+0x4e/0x80 arch/x86/entry/entry_64.S:604
> >
> > Signed-off-by: Archie Pusaka <apusaka@chromium.org>
> > Reported-by: syzbot+abfc0f5e668d4099af73@syzkaller.appspotmail.com
> > Reviewed-by: Alain Michaud <alainm@chromium.org>
> > Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > Reviewed-by: Guenter Roeck <groeck@chromium.org>
> > ---
> >
> > net/bluetooth/l2cap_sock.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
> > index f1b1edd0b697..b86fd8cc4dc1 100644
> > --- a/net/bluetooth/l2cap_sock.c
> > +++ b/net/bluetooth/l2cap_sock.c
> > @@ -182,6 +182,13 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr,
> >
> >       BT_DBG("sk %p", sk);
> >
> > +     lock_sock(sk);
> > +     if (sock_flag(sk, SOCK_ZAPPED)) {
> > +             release_sock(sk);
> > +             return -EINVAL;
> > +     }
> > +     release_sock(sk);
> > +
>
> hmmm. I wonder if this would look better and easy to see that the locking is done correctly.
>
>         lock_sock(sk);
>         zapped = sock_flag(sk, SOCK_ZAPPED);
>         release_sock(sk);
>
>         if (zapped)
>                 return -EINVAL;
>
> Regards
>
> Marcel
>
diff mbox series

Patch

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index f1b1edd0b697..b86fd8cc4dc1 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -182,6 +182,13 @@  static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr,
 
 	BT_DBG("sk %p", sk);
 
+	lock_sock(sk);
+	if (sock_flag(sk, SOCK_ZAPPED)) {
+		release_sock(sk);
+		return -EINVAL;
+	}
+	release_sock(sk);
+
 	if (!addr || alen < offsetofend(struct sockaddr, sa_family) ||
 	    addr->sa_family != AF_BLUETOOTH)
 		return -EINVAL;