kernel/git/stable/linux.git/drivers/net/tun.c, branch linux-4.13.y

tun/tap: sanitize TUNSETSNDBUF input

2017-11-18T10:30:39+00:00

[ Upstream commit 93161922c658c714715686cd0cf69b090cb9bf1d ] Syzkaller found several variants of the lockup below by setting negative values with the TUNSETSNDBUF ioctl. This patch adds a sanity check to both the tun and tap versions of this ioctl. watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [repro:2389] Modules linked in: irq event stamp: 329692056 hardirqs last enabled at (329692055): [] _raw_spin_unlock_irqrestore+0x31/0x75 hardirqs last disabled at (329692056): [] apic_timer_interrupt+0x98/0xb0 softirqs last enabled at (35659740): [] __do_softirq+0x328/0x48c softirqs last disabled at (35659731): [] irq_exit+0xbc/0xd0 CPU: 0 PID: 2389 Comm: repro Not tainted 4.14.0-rc7 #23 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff880009452140 task.stack: ffff880006a20000 RIP: 0010:_raw_spin_lock_irqsave+0x11/0x80 RSP: 0018:ffff880006a27c50 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: ffff880009ac68d0 RBX: ffff880006a27ce0 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffff880006a27ce0 RDI: ffff880009ac6900 RBP: ffff880006a27c60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 000000000063ff00 R12: ffff880009ac6900 R13: ffff880006a27cf8 R14: 0000000000000001 R15: ffff880006a27cf8 FS: 00007f4be4838700(0000) GS:ffff88000cc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020101000 CR3: 0000000009616000 CR4: 00000000000006f0 Call Trace: prepare_to_wait+0x26/0xc0 sock_alloc_send_pskb+0x14e/0x270 ? remove_wait_queue+0x60/0x60 tun_get_user+0x2cc/0x19d0 ? __tun_get+0x60/0x1b0 tun_chr_write_iter+0x57/0x86 __vfs_write+0x156/0x1e0 vfs_write+0xf7/0x230 SyS_write+0x57/0xd0 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x7f4be4356df9 RSP: 002b:00007ffc18101c08 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4be4356df9 RDX: 0000000000000046 RSI: 0000000020101000 RDI: 0000000000000005 RBP: 00007ffc18101c40 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000293 R12: 0000559c75f64780 R13: 00007ffc18101d30 R14: 0000000000000000 R15: 0000000000000000 Fixes: 33dccbb050bb ("tun: Limit amount of queued packets per device") Fixes: 20d29d7a916a ("net: macvtap driver") Signed-off-by: Craig Gallek Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tun: allow positive return values on dev_get_valid_name() call

2017-11-18T10:30:38+00:00

[ Upstream commit 5c25f65fd1e42685f7ccd80e0621829c105785d9 ] If the name argument of dev_get_valid_name() contains "%d", it will try to assign it a unit number in __dev__alloc_name() and return either the unit number (>= 0) or an error code (< 0). Considering positive values as error values prevent tun device creations relying this mechanism, therefor we should only consider negative values as errors here. Signed-off-by: Julien Gomes Acked-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tun: call dev_get_valid_name() before register_netdevice()

2017-11-18T10:30:36+00:00

[ Upstream commit 0ad646c81b2182f7fa67ec0c8c825e0ee165696d ] register_netdevice() could fail early when we have an invalid dev name, in which case ->ndo_uninit() is not called. For tun device, this is a problem because a timer etc. are already initialized and it expects ->ndo_uninit() to clean them up. We could move these initializations into a ->ndo_init() so that register_netdevice() knows better, however this is still complicated due to the logic in tun_detach(). Therefore, I choose to just call dev_get_valid_name() before register_netdevice(), which is quicker and much easier to audit. And for this specific case, it is already enough. Fixes: 96442e42429e ("tuntap: choose the txq based on rxq") Reported-by: Dmitry Alexeev Cc: Jason Wang Cc: "Michael S. Tsirkin" Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tun: bail out from tun_get_user() if the skb is empty

2017-10-12T09:56:05+00:00

[ Upstream commit 2580c4c17aee3ad58e9751012bad278dd074ccae ] KMSAN (https://github.com/google/kmsan) reported accessing uninitialized skb->data[0] in the case the skb is empty (i.e. skb->len is 0): ================================================ BUG: KMSAN: use of uninitialized memory in tun_get_user+0x19ba/0x3770 CPU: 0 PID: 3051 Comm: probe Not tainted 4.13.0+ #3140 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: ... __msan_warning_32+0x66/0xb0 mm/kmsan/kmsan_instr.c:477 tun_get_user+0x19ba/0x3770 drivers/net/tun.c:1301 tun_chr_write_iter+0x19f/0x300 drivers/net/tun.c:1365 call_write_iter ./include/linux/fs.h:1743 new_sync_write fs/read_write.c:457 __vfs_write+0x6c3/0x7f0 fs/read_write.c:470 vfs_write+0x3e4/0x770 fs/read_write.c:518 SYSC_write+0x12f/0x2b0 fs/read_write.c:565 SyS_write+0x55/0x80 fs/read_write.c:557 do_syscall_64+0x242/0x330 arch/x86/entry/common.c:284 entry_SYSCALL64_slow_path+0x25/0x25 arch/x86/entry/entry_64.S:245 ... origin: ... kmsan_poison_shadow+0x6e/0xc0 mm/kmsan/kmsan.c:211 slab_alloc_node mm/slub.c:2732 __kmalloc_node_track_caller+0x351/0x370 mm/slub.c:4351 __kmalloc_reserve net/core/skbuff.c:138 __alloc_skb+0x26a/0x810 net/core/skbuff.c:231 alloc_skb ./include/linux/skbuff.h:903 alloc_skb_with_frags+0x1d7/0xc80 net/core/skbuff.c:4756 sock_alloc_send_pskb+0xabf/0xfe0 net/core/sock.c:2037 tun_alloc_skb drivers/net/tun.c:1144 tun_get_user+0x9a8/0x3770 drivers/net/tun.c:1274 tun_chr_write_iter+0x19f/0x300 drivers/net/tun.c:1365 call_write_iter ./include/linux/fs.h:1743 new_sync_write fs/read_write.c:457 __vfs_write+0x6c3/0x7f0 fs/read_write.c:470 vfs_write+0x3e4/0x770 fs/read_write.c:518 SYSC_write+0x12f/0x2b0 fs/read_write.c:565 SyS_write+0x55/0x80 fs/read_write.c:557 do_syscall_64+0x242/0x330 arch/x86/entry/common.c:284 return_from_SYSCALL_64+0x0/0x6a arch/x86/entry/entry_64.S:245 ================================================ Make sure tun_get_user() doesn't touch skb->data[0] unless there is actual data. C reproducer below: ========================== // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include int main() { int sock = socket(PF_INET, SOCK_STREAM, IPPROTO_IP); int tun_fd = open("/dev/net/tun", O_RDWR); struct ifreq req; memset(&req, 0, sizeof(struct ifreq)); strcpy((char*)&req.ifr_name, "gre0"); req.ifr_flags = IFF_UP | IFF_MULTICAST; ioctl(tun_fd, TUNSETIFF, &req); ioctl(sock, SIOCSIFFLAGS, "gre0"); write(tun_fd, "hi", 0); return 0; } ========================== Signed-off-by: Alexander Potapenko Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tun: handle register_netdevice() failures properly

2017-08-18T22:55:35+00:00

syzkaller reported a double free [1], caused by the fact that tun driver was not updated properly when priv_destructor was added. When/if register_netdevice() fails, priv_destructor() must have been called already. [1] BUG: KASAN: double-free or invalid-free in selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023 CPU: 0 PID: 2919 Comm: syzkaller227220 Not tainted 4.13.0-rc4+ #23 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_address_description+0x7f/0x260 mm/kasan/report.c:252 kasan_report_double_free+0x55/0x80 mm/kasan/report.c:333 kasan_slab_free+0xa0/0xc0 mm/kasan/kasan.c:514 __cache_free mm/slab.c:3503 [inline] kfree+0xd3/0x260 mm/slab.c:3820 selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023 security_tun_dev_free_security+0x48/0x80 security/security.c:1512 tun_set_iff drivers/net/tun.c:1884 [inline] __tun_chr_ioctl+0x2ce6/0x3d50 drivers/net/tun.c:2064 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x443ff9 RSP: 002b:00007ffc34271f68 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443ff9 RDX: 0000000020533000 RSI: 00000000400454ca RDI: 0000000000000003 RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000401ce0 R13: 0000000000401d70 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 2919: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x101/0x6f0 mm/slab.c:3627 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:666 [inline] selinux_tun_dev_alloc_security+0x49/0x170 security/selinux/hooks.c:5012 security_tun_dev_alloc_security+0x6d/0xa0 security/security.c:1506 tun_set_iff drivers/net/tun.c:1839 [inline] __tun_chr_ioctl+0x1730/0x3d50 drivers/net/tun.c:2064 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 2919: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x6e/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kfree+0xd3/0x260 mm/slab.c:3820 selinux_tun_dev_free_security+0x15/0x20 security/selinux/hooks.c:5023 security_tun_dev_free_security+0x48/0x80 security/security.c:1512 tun_free_netdev+0x13b/0x1b0 drivers/net/tun.c:1563 register_netdevice+0x8d0/0xee0 net/core/dev.c:7605 tun_set_iff drivers/net/tun.c:1859 [inline] __tun_chr_ioctl+0x1caf/0x3d50 drivers/net/tun.c:2064 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2309 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe The buggy address belongs to the object at ffff8801d2843b40 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff8801d2843b40, ffff8801d2843b60) The buggy address belongs to the page: page:ffffea000660cea8 count:1 mapcount:0 mapping:ffff8801d2843000 index:0xffff8801d2843fc1 flags: 0x200000000000100(slab) raw: 0200000000000100 ffff8801d2843000 ffff8801d2843fc1 000000010000003f raw: ffffea0006626a40 ffffea00066141a0 ffff8801dbc00100 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d2843a00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8801d2843a80: 00 00 00 fc fc fc fc fc fb fb fb fb fc fc fc fc >ffff8801d2843b00: 00 00 00 00 fc fc fc fc fb fb fb fb fc fc fc fc ^ ffff8801d2843b80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8801d2843c00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ================================================================== Fixes: cf124db566e6 ("net: Fix inconsistent teardown and release of private netdev state.") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tun/tap: Add the missed return value check of register_netdevice_notifier

2017-07-24T20:44:31+00:00

There is some codes of tun/tap module which did not check the return value of register_netdevice_notifier. Add the check now. Signed-off-by: Tonghao Zhang Signed-off-by: David S. Miller

net: add netlink_ext_ack argument to rtnl_link_ops.validate

2017-06-27T03:13:22+00:00

Add support for extended error reporting. Signed-off-by: Matthias Schiffer Acked-by: David Ahern Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-06-15T15:59:32+00:00

The conflicts were two cases of overlapping changes in batman-adv and the qed driver. Signed-off-by: David S. Miller

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

2017-06-07T19:53:24+00:00

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

tun: use symmetric hash

2017-06-06T20:23:31+00:00

Tun actually expects a symmetric hash for queue selecting to work correctly, otherwise packets belongs to a single flow may be redirected to the wrong queue. So this patch switch to use __skb_get_hash_symmetric(). Signed-off-by: Jason Wang Signed-off-by: David S. Miller