kernel.git/drivers/net/hamradio/6pack.c, branch linux-5.0.y

net/hamradio/6pack: use mod_timer() to rearm timers

2019-01-02T18:27:01Z

Using del_timer() + add_timer() is generally unsafe on SMP, as noticed by syzbot. Use mod_timer() instead. kernel BUG at kernel/time/timer.c:1136! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 1026 Comm: kworker/u4:4 Not tainted 4.20.0+ #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound flush_to_ldisc RIP: 0010:add_timer kernel/time/timer.c:1136 [inline] RIP: 0010:add_timer+0xa81/0x1470 kernel/time/timer.c:1134 Code: 4d 89 7d 40 48 c7 85 70 fe ff ff 00 00 00 00 c7 85 7c fe ff ff ff ff ff ff 48 89 85 90 fe ff ff e9 e6 f7 ff ff e8 cf 42 12 00 <0f> 0b e8 c8 42 12 00 0f 0b e8 c1 42 12 00 4c 89 bd 60 fe ff ff e9 RSP: 0018:ffff8880a7fdf5a8 EFLAGS: 00010293 RAX: ffff8880a7846340 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff816f3ee1 RDI: ffff88808a514ff8 RBP: ffff8880a7fdf760 R08: 0000000000000007 R09: ffff8880a7846c58 R10: ffff8880a7846340 R11: 0000000000000000 R12: ffff88808a514ff8 R13: ffff88808a514ff8 R14: ffff88808a514dc0 R15: 0000000000000030 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000061c500 CR3: 00000000994d9000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: decode_prio_command drivers/net/hamradio/6pack.c:903 [inline] sixpack_decode drivers/net/hamradio/6pack.c:971 [inline] sixpack_receive_buf drivers/net/hamradio/6pack.c:457 [inline] sixpack_receive_buf+0xf9c/0x1470 drivers/net/hamradio/6pack.c:434 tty_ldisc_receive_buf+0x164/0x1c0 drivers/tty/tty_buffer.c:465 tty_port_default_receive_buf+0x114/0x190 drivers/tty/tty_port.c:38 receive_buf drivers/tty/tty_buffer.c:481 [inline] flush_to_ldisc+0x3b2/0x590 drivers/tty/tty_buffer.c:533 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot Cc: Andreas Koensgen Signed-off-by: David S. Miller

hamradio, ppp: change semaphore to completion

2018-12-14T21:27:10Z

ppp and hamradio have copies of the same code that uses a semaphore in place of a completion for historic reasons. Make it use the proper interface instead in all copies. Signed-off-by: Arnd Bergmann Signed-off-by: David S. Miller

change semantics of ldisc ->compat_ioctl()

2018-10-13T04:50:53Z

First of all, make it return int. Returning long when native method had never allowed that is ridiculous and inconvenient. More importantly, change the caller; if ldisc ->compat_ioctl() is NULL or returns -ENOIOCTLCMD, tty_compat_ioctl() will try to feed cmd and compat_ptr(arg) to ldisc's native ->ioctl(). That simplifies ->compat_ioctl() instances quite a bit - they only need to deal with ioctls that are neither generic tty ones (those would get shunted off to tty_ioctl()) nor simple compat pointer ones. Note that something like TCFLSH won't reach ->compat_ioctl(), even if ldisc ->ioctl() does handle it - it will be recognized earlier and passed to tty_ioctl() (and ultimately - ldisc ->ioctl()). For many ldiscs it means that NULL ->compat_ioctl() does the right thing. Those where it won't serve (see e.g. n_r3964.c) are also easily dealt with - we need to handle the numeric-argument ioctls (calling the native instance) and, if such would exist, the ioctls that need layout conversion, etc. All in-tree ldiscs dealt with. Signed-off-by: Al Viro

net/hamradio/6pack: remove redundant variable channel

2018-07-05T10:34:45Z

Variable channel is being assigned but is never used hence it is redundant and can be removed. Cleans up two clang warnings: warning: variable 'channel' set but not used [-Wunused-but-set-variable] Signed-off-by: Colin Ian King Signed-off-by: David S. Miller

drivers, net, hamradio: convert sixpack.refcnt from atomic_t to refcount_t

2017-10-22T01:22:39Z

atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable sixpack.refcnt is used as pure reference counter. Convert it to refcount_t and fix up the operations. Suggested-by: Kees Cook Reviewed-by: David Windsor Reviewed-by: Hans Liljestrand Signed-off-by: Elena Reshetova Signed-off-by: David S. Miller

net/hamradio/6pack: Convert timers to use timer_setup()

2017-10-18T11:39:37Z

In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Andreas Koensgen Cc: linux-hams@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook Signed-off-by: David S. Miller

drivers: net: hamradio: use setup_timer() helper.

2017-09-21T18:44:43Z

Use setup_timer function instead of initializing timer with the function and data fields. Signed-off-by: Allen Pais Signed-off-by: David S. Miller

net: Fix inconsistent teardown and release of private netdev state.

2017-06-07T19:53:24Z

Network devices can allocate reasources and private memory using netdev_ops->ndo_init(). However, the release of these resources can occur in one of two different places. Either netdev_ops->ndo_uninit() or netdev->destructor(). The decision of which operation frees the resources depends upon whether it is necessary for all netdev refs to be released before it is safe to perform the freeing. netdev_ops->ndo_uninit() presumably can occur right after the NETDEV_UNREGISTER notifier completes and the unicast and multicast address lists are flushed. netdev->destructor(), on the other hand, does not run until the netdev references all go away. Further complicating the situation is that netdev->destructor() almost universally does also a free_netdev(). This creates a problem for the logic in register_netdevice(). Because all callers of register_netdevice() manage the freeing of the netdev, and invoke free_netdev(dev) if register_netdevice() fails. If netdev_ops->ndo_init() succeeds, but something else fails inside of register_netdevice(), it does call ndo_ops->ndo_uninit(). But it is not able to invoke netdev->destructor(). This is because netdev->destructor() will do a free_netdev() and then the caller of register_netdevice() will do the same. However, this means that the resources that would normally be released by netdev->destructor() will not be. Over the years drivers have added local hacks to deal with this, by invoking their destructor parts by hand when register_netdevice() fails. Many drivers do not try to deal with this, and instead we have leaks. Let's close this hole by formalizing the distinction between what private things need to be freed up by netdev->destructor() and whether the driver needs unregister_netdevice() to perform the free_netdev(). netdev->priv_destructor() performs all actions to free up the private resources that used to be freed by netdev->destructor(), except for free_netdev(). netdev->needs_free_netdev is a boolean that indicates whether free_netdev() should be done at the end of unregister_netdevice(). Now, register_netdevice() can sanely release all resources after ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit() and netdev->priv_destructor(). And at the end of unregister_netdevice(), we invoke netdev->priv_destructor() and optionally call free_netdev(). Signed-off-by: David S. Miller

Replace with globally

2016-12-24T19:46:01Z

This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*' sed -i -e "s!$PATT!#include !" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro Signed-off-by: Linus Torvalds

6pack: fix buffer length mishandling

2016-09-21T02:51:30Z

Dmitry Vyukov wrote: > different runs). Looking at code, the following looks suspicious -- we > limit copy by 512 bytes, but use the original count which can be > larger than 512: > > static void sixpack_receive_buf(struct tty_struct *tty, > const unsigned char *cp, char *fp, int count) > { > unsigned char buf[512]; > .... > memcpy(buf, cp, count < sizeof(buf) ? count : sizeof(buf)); > .... > sixpack_decode(sp, buf, count1); With the sane tty locking we now have I believe the following is safe as we consume the bytes and move them into the decoded buffer before returning. Signed-off-by: Alan Cox Signed-off-by: David S. Miller