linux-stable.git/drivers/net, branch v3.16.79 Linux kernel stable tree can: peak_usb: fix slab info leak 2019-12-10T18:01:38+00:00 Johan Hovold johan@kernel.org 2019-10-23T08:27:05+00:00 f13615187cd8069c0f1c492e8f244a0c69d0663e commit f7a1337f0d29b98733c8824e165fca3371d7d4fd upstream. Fix a small slab info leak due to a failure to clear the command buffer at allocation. The first 16 bytes of the command buffer are always sent to the device in pcan_usb_send_cmd() even though only the first two may have been initialised in case no argument payload is provided (e.g. when waiting for a response). Fixes: bb4785551f64 ("can: usb: PEAK-System Technik USB adapters driver core") Reported-by: syzbot+863724e7128e14b26732@syzkaller.appspotmail.com Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit f7a1337f0d29b98733c8824e165fca3371d7d4fd upstream.

Fix a small slab info leak due to a failure to clear the command buffer
at allocation.

The first 16 bytes of the command buffer are always sent to the device
in pcan_usb_send_cmd() even though only the first two may have been
initialised in case no argument payload is provided (e.g. when waiting
for a response).

Fixes: bb4785551f64 ("can: usb: PEAK-System Technik USB adapters driver core")
Reported-by: syzbot+863724e7128e14b26732@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mwifiex: pcie: Fix memory leak in mwifiex_pcie_init_evt_ring 2019-12-10T18:01:31+00:00 Navid Emamdoost navid.emamdoost@gmail.com 2019-10-04T20:16:48+00:00 914927c7bac4ecd2351bdee0cd5b2b1c11150342 commit d10dcb615c8e29d403a24d35f8310a7a53e3050c upstream. In mwifiex_pcie_init_evt_ring, a new skb is allocated which should be released if mwifiex_map_pci_memory() fails. The release for skb and card->evtbd_ring_vbase is added. Fixes: 0732484b47b5 ("mwifiex: separate ring initialization and ring creation routines") Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com> Acked-by: Ganapathi Bhat <gbhat@marvell.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit d10dcb615c8e29d403a24d35f8310a7a53e3050c upstream.

In mwifiex_pcie_init_evt_ring, a new skb is allocated which should be
released if mwifiex_map_pci_memory() fails. The release for skb and
card->evtbd_ring_vbase is added.

Fixes: 0732484b47b5 ("mwifiex: separate ring initialization and ring creation routines")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Acked-by: Ganapathi Bhat <gbhat@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mwifiex: pcie: Fix memory leak in mwifiex_pcie_alloc_cmdrsp_buf 2019-12-10T18:01:31+00:00 Navid Emamdoost navid.emamdoost@gmail.com 2019-10-04T20:08:52+00:00 f0eed3b1a34f1e7d8b2c06ad5ddf0ea60aea71ca commit db8fd2cde93227e566a412cf53173ffa227998bc upstream. In mwifiex_pcie_alloc_cmdrsp_buf, a new skb is allocated which should be released if mwifiex_map_pci_memory() fails. The release is added. Fixes: fc3314609047 ("mwifiex: use pci_alloc/free_consistent APIs for PCIe") Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com> Acked-by: Ganapathi Bhat <gbhat@marvell.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit db8fd2cde93227e566a412cf53173ffa227998bc upstream.

In mwifiex_pcie_alloc_cmdrsp_buf, a new skb is allocated which should be
released if mwifiex_map_pci_memory() fails. The release is added.

Fixes: fc3314609047 ("mwifiex: use pci_alloc/free_consistent APIs for PCIe")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Acked-by: Ganapathi Bhat <gbhat@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
can: gs_usb: gs_can_open(): prevent memory leak 2019-12-10T18:01:30+00:00 Navid Emamdoost navid.emamdoost@gmail.com 2019-09-20T02:44:38+00:00 f26d980434a06f44b693a26a87aa5300fa4016fd commit fb5be6a7b4863ecc44963bb80ca614584b6c7817 upstream. In gs_can_open() if usb_submit_urb() fails the allocated urb should be released. Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices") Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit fb5be6a7b4863ecc44963bb80ca614584b6c7817 upstream.

In gs_can_open() if usb_submit_urb() fails the allocated urb should be
released.

Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
wimax: i2400: Fix memory leak in i2400m_op_rfkill_sw_toggle 2019-12-10T18:01:30+00:00 Navid Emamdoost navid.emamdoost@gmail.com 2019-10-26T04:53:30+00:00 311edf1932ef820b3e101d52f2d79f371fd4d186 commit 6f3ef5c25cc762687a7341c18cbea5af54461407 upstream. In the implementation of i2400m_op_rfkill_sw_toggle() the allocated buffer for cmd should be released before returning. The documentation for i2400m_msg_to_dev() says when it returns the buffer can be reused. Meaning cmd should be released in either case. Move kfree(cmd) before return to be reached by all execution paths. Fixes: 2507e6ab7a9a ("wimax: i2400: fix memory leak") Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 6f3ef5c25cc762687a7341c18cbea5af54461407 upstream.

In the implementation of i2400m_op_rfkill_sw_toggle() the allocated
buffer for cmd should be released before returning. The
documentation for i2400m_msg_to_dev() says when it returns the buffer
can be reused. Meaning cmd should be released in either case. Move
kfree(cmd) before return to be reached by all execution paths.

Fixes: 2507e6ab7a9a ("wimax: i2400: fix memory leak")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
wimax: i2400: fix memory leak 2019-12-10T18:01:29+00:00 Navid Emamdoost navid.emamdoost@gmail.com 2019-09-10T23:01:40+00:00 50e479c12f37cc24fea72bcb5da64ed127395f14 commit 2507e6ab7a9a440773be476141a255934468c5ef upstream. In i2400m_op_rfkill_sw_toggle cmd buffer should be released along with skb response. Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 2507e6ab7a9a440773be476141a255934468c5ef upstream.

In i2400m_op_rfkill_sw_toggle cmd buffer should be released along with
skb response.

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
net/phy: fix DP83865 10 Mbps HDX loopback disable function 2019-12-10T18:01:23+00:00 Peter Mamonov pmamonov@gmail.com 2019-09-18T16:27:55+00:00 183fb1de1665e1d6eea989414dea657caf75e474 commit e47488b2df7f9cb405789c7f5d4c27909fc597ae upstream. According to the DP83865 datasheet "the 10 Mbps HDX loopback can be disabled in the expanded memory register 0x1C0.1". The driver erroneously used bit 0 instead of bit 1. Fixes: 4621bf129856 ("phy: Add file missed in previous commit.") Signed-off-by: Peter Mamonov <pmamonov@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit e47488b2df7f9cb405789c7f5d4c27909fc597ae upstream.

According to the DP83865 datasheet "the 10 Mbps HDX loopback can be
disabled in the expanded memory register 0x1C0.1". The driver erroneously
used bit 0 instead of bit 1.

Fixes: 4621bf129856 ("phy: Add file missed in previous commit.")
Signed-off-by: Peter Mamonov <pmamonov@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
can: mcp251x: mcp251x_hw_reset(): allow more time after a reset 2019-12-10T18:01:13+00:00 Marc Kleine-Budde mkl@pengutronix.de 2019-08-13T14:01:02+00:00 5f1ff0c72deb91961df0ba31436fc22dab411fc2 commit d84ea2123f8d27144e3f4d58cd88c9c6ddc799de upstream. Some boards take longer than 5ms to power up after a reset, so allow some retries attempts before giving up. Fixes: ff06d611a31c ("can: mcp251x: Improve mcp251x_hw_reset()") Tested-by: Sean Nyekjaer <sean@geanix.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit d84ea2123f8d27144e3f4d58cd88c9c6ddc799de upstream.

Some boards take longer than 5ms to power up after a reset, so allow
some retries attempts before giving up.

Fixes: ff06d611a31c ("can: mcp251x: Improve mcp251x_hw_reset()")
Tested-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
libertas_tf: Use correct channel range in lbtf_geo_init 2019-12-10T18:01:10+00:00 YueHaibing yuehaibing@huawei.com 2019-07-16T14:42:18+00:00 36129023c7ee588b24cd663217926fc3156ff197 commit 2ec4ad49b98e4a14147d04f914717135eca7c8b1 upstream. It seems we should use 'range' instead of 'priv->range' in lbtf_geo_init(), because 'range' is the corret one related to current regioncode. Reported-by: Hulk Robot <hulkci@huawei.com> Fixes: 691cdb49388b ("libertas_tf: command helper functions for libertas_tf") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 2ec4ad49b98e4a14147d04f914717135eca7c8b1 upstream.

It seems we should use 'range' instead of 'priv->range'
in lbtf_geo_init(), because 'range' is the corret one
related to current regioncode.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 691cdb49388b ("libertas_tf: command helper functions for libertas_tf")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tun: fix use-after-free when register netdev failed 2019-11-22T15:57:28+00:00 Yang Yingliang yangyingliang@huawei.com 2019-09-10T10:56:57+00:00 9b3bfbbfa8b5ebeff76f81d620b8a3a36bc4c1f9 commit 77f22f92dff8e7b45c7786a430626d38071d4670 upstream. I got a UAF repport in tun driver when doing fuzzy test: [ 466.269490] ================================================================== [ 466.271792] BUG: KASAN: use-after-free in tun_chr_read_iter+0x2ca/0x2d0 [ 466.271806] Read of size 8 at addr ffff888372139250 by task tun-test/2699 [ 466.271810] [ 466.271824] CPU: 1 PID: 2699 Comm: tun-test Not tainted 5.3.0-rc1-00001-g5a9433db2614-dirty #427 [ 466.271833] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 466.271838] Call Trace: [ 466.271858] dump_stack+0xca/0x13e [ 466.271871] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271890] print_address_description+0x79/0x440 [ 466.271906] ? vprintk_func+0x5e/0xf0 [ 466.271920] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271935] __kasan_report+0x15c/0x1df [ 466.271958] ? tun_chr_read_iter+0x2ca/0x2d0 [ 466.271976] kasan_report+0xe/0x20 [ 466.271987] tun_chr_read_iter+0x2ca/0x2d0 [ 466.272013] do_iter_readv_writev+0x4b7/0x740 [ 466.272032] ? default_llseek+0x2d0/0x2d0 [ 466.272072] do_iter_read+0x1c5/0x5e0 [ 466.272110] vfs_readv+0x108/0x180 [ 466.299007] ? compat_rw_copy_check_uvector+0x440/0x440 [ 466.299020] ? fsnotify+0x888/0xd50 [ 466.299040] ? __fsnotify_parent+0xd0/0x350 [ 466.299064] ? fsnotify_first_mark+0x1e0/0x1e0 [ 466.304548] ? vfs_write+0x264/0x510 [ 466.304569] ? ksys_write+0x101/0x210 [ 466.304591] ? do_preadv+0x116/0x1a0 [ 466.304609] do_preadv+0x116/0x1a0 [ 466.309829] do_syscall_64+0xc8/0x600 [ 466.309849] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.309861] RIP: 0033:0x4560f9 [ 466.309875] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 466.309889] RSP: 002b:00007ffffa5166e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000127 [ 466.322992] RAX: ffffffffffffffda RBX: 0000000000400460 RCX: 00000000004560f9 [ 466.322999] RDX: 0000000000000003 RSI: 00000000200008c0 RDI: 0000000000000003 [ 466.323007] RBP: 00007ffffa516700 R08: 0000000000000004 R09: 0000000000000000 [ 466.323014] R10: 0000000000000000 R11: 0000000000000206 R12: 000000000040cb10 [ 466.323021] R13: 0000000000000000 R14: 00000000006d7018 R15: 0000000000000000 [ 466.323057] [ 466.323064] Allocated by task 2605: [ 466.335165] save_stack+0x19/0x80 [ 466.336240] __kasan_kmalloc.constprop.8+0xa0/0xd0 [ 466.337755] kmem_cache_alloc+0xe8/0x320 [ 466.339050] getname_flags+0xca/0x560 [ 466.340229] user_path_at_empty+0x2c/0x50 [ 466.341508] vfs_statx+0xe6/0x190 [ 466.342619] __do_sys_newstat+0x81/0x100 [ 466.343908] do_syscall_64+0xc8/0x600 [ 466.345303] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.347034] [ 466.347517] Freed by task 2605: [ 466.348471] save_stack+0x19/0x80 [ 466.349476] __kasan_slab_free+0x12e/0x180 [ 466.350726] kmem_cache_free+0xc8/0x430 [ 466.351874] putname+0xe2/0x120 [ 466.352921] filename_lookup+0x257/0x3e0 [ 466.354319] vfs_statx+0xe6/0x190 [ 466.355498] __do_sys_newstat+0x81/0x100 [ 466.356889] do_syscall_64+0xc8/0x600 [ 466.358037] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 466.359567] [ 466.360050] The buggy address belongs to the object at ffff888372139100 [ 466.360050] which belongs to the cache names_cache of size 4096 [ 466.363735] The buggy address is located 336 bytes inside of [ 466.363735] 4096-byte region [ffff888372139100, ffff88837213a100) [ 466.367179] The buggy address belongs to the page: [ 466.368604] page:ffffea000dc84e00 refcount:1 mapcount:0 mapping:ffff8883df1b4f00 index:0x0 compound_mapcount: 0 [ 466.371582] flags: 0x2fffff80010200(slab|head) [ 466.372910] raw: 002fffff80010200 dead000000000100 dead000000000122 ffff8883df1b4f00 [ 466.375209] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 [ 466.377778] page dumped because: kasan: bad access detected [ 466.379730] [ 466.380288] Memory state around the buggy address: [ 466.381844] ffff888372139100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.384009] ffff888372139180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.386131] >ffff888372139200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.388257] ^ [ 466.390234] ffff888372139280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.392512] ffff888372139300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 466.394667] ================================================================== tun_chr_read_iter() accessed the memory which freed by free_netdev() called by tun_set_iff(): CPUA CPUB tun_set_iff() alloc_netdev_mqs() tun_attach() tun_chr_read_iter() tun_get() tun_do_read() tun_ring_recv() register_netdevice() <-- inject error goto err_detach tun_detach_all() <-- set RCV_SHUTDOWN free_netdev() <-- called from err_free_dev path netdev_freemem() <-- free the memory without check refcount (In this path, the refcount cannot prevent freeing the memory of dev, and the memory will be used by dev_put() called by tun_chr_read_iter() on CPUB.) (Break from tun_ring_recv(), because RCV_SHUTDOWN is set) tun_put() dev_put() <-- use the memory freed by netdev_freemem() Put the publishing of tfile->tun after register_netdevice(), so tun_get() won't get the tun pointer that freed by err_detach path if register_netdevice() failed. Fixes: eb0fb363f920 ("tuntap: attach queue 0 before registering netdevice") Reported-by: Hulk Robot <hulkci@huawei.com> Suggested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 77f22f92dff8e7b45c7786a430626d38071d4670 upstream.

I got a UAF repport in tun driver when doing fuzzy test:

[  466.269490] ==================================================================
[  466.271792] BUG: KASAN: use-after-free in tun_chr_read_iter+0x2ca/0x2d0
[  466.271806] Read of size 8 at addr ffff888372139250 by task tun-test/2699
[  466.271810]
[  466.271824] CPU: 1 PID: 2699 Comm: tun-test Not tainted 5.3.0-rc1-00001-g5a9433db2614-dirty #427
[  466.271833] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[  466.271838] Call Trace:
[  466.271858]  dump_stack+0xca/0x13e
[  466.271871]  ? tun_chr_read_iter+0x2ca/0x2d0
[  466.271890]  print_address_description+0x79/0x440
[  466.271906]  ? vprintk_func+0x5e/0xf0
[  466.271920]  ? tun_chr_read_iter+0x2ca/0x2d0
[  466.271935]  __kasan_report+0x15c/0x1df
[  466.271958]  ? tun_chr_read_iter+0x2ca/0x2d0
[  466.271976]  kasan_report+0xe/0x20
[  466.271987]  tun_chr_read_iter+0x2ca/0x2d0
[  466.272013]  do_iter_readv_writev+0x4b7/0x740
[  466.272032]  ? default_llseek+0x2d0/0x2d0
[  466.272072]  do_iter_read+0x1c5/0x5e0
[  466.272110]  vfs_readv+0x108/0x180
[  466.299007]  ? compat_rw_copy_check_uvector+0x440/0x440
[  466.299020]  ? fsnotify+0x888/0xd50
[  466.299040]  ? __fsnotify_parent+0xd0/0x350
[  466.299064]  ? fsnotify_first_mark+0x1e0/0x1e0
[  466.304548]  ? vfs_write+0x264/0x510
[  466.304569]  ? ksys_write+0x101/0x210
[  466.304591]  ? do_preadv+0x116/0x1a0
[  466.304609]  do_preadv+0x116/0x1a0
[  466.309829]  do_syscall_64+0xc8/0x600
[  466.309849]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  466.309861] RIP: 0033:0x4560f9
[  466.309875] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
[  466.309889] RSP: 002b:00007ffffa5166e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000127
[  466.322992] RAX: ffffffffffffffda RBX: 0000000000400460 RCX: 00000000004560f9
[  466.322999] RDX: 0000000000000003 RSI: 00000000200008c0 RDI: 0000000000000003
[  466.323007] RBP: 00007ffffa516700 R08: 0000000000000004 R09: 0000000000000000
[  466.323014] R10: 0000000000000000 R11: 0000000000000206 R12: 000000000040cb10
[  466.323021] R13: 0000000000000000 R14: 00000000006d7018 R15: 0000000000000000
[  466.323057]
[  466.323064] Allocated by task 2605:
[  466.335165]  save_stack+0x19/0x80
[  466.336240]  __kasan_kmalloc.constprop.8+0xa0/0xd0
[  466.337755]  kmem_cache_alloc+0xe8/0x320
[  466.339050]  getname_flags+0xca/0x560
[  466.340229]  user_path_at_empty+0x2c/0x50
[  466.341508]  vfs_statx+0xe6/0x190
[  466.342619]  __do_sys_newstat+0x81/0x100
[  466.343908]  do_syscall_64+0xc8/0x600
[  466.345303]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  466.347034]
[  466.347517] Freed by task 2605:
[  466.348471]  save_stack+0x19/0x80
[  466.349476]  __kasan_slab_free+0x12e/0x180
[  466.350726]  kmem_cache_free+0xc8/0x430
[  466.351874]  putname+0xe2/0x120
[  466.352921]  filename_lookup+0x257/0x3e0
[  466.354319]  vfs_statx+0xe6/0x190
[  466.355498]  __do_sys_newstat+0x81/0x100
[  466.356889]  do_syscall_64+0xc8/0x600
[  466.358037]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  466.359567]
[  466.360050] The buggy address belongs to the object at ffff888372139100
[  466.360050]  which belongs to the cache names_cache of size 4096
[  466.363735] The buggy address is located 336 bytes inside of
[  466.363735]  4096-byte region [ffff888372139100, ffff88837213a100)
[  466.367179] The buggy address belongs to the page:
[  466.368604] page:ffffea000dc84e00 refcount:1 mapcount:0 mapping:ffff8883df1b4f00 index:0x0 compound_mapcount: 0
[  466.371582] flags: 0x2fffff80010200(slab|head)
[  466.372910] raw: 002fffff80010200 dead000000000100 dead000000000122 ffff8883df1b4f00
[  466.375209] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
[  466.377778] page dumped because: kasan: bad access detected
[  466.379730]
[  466.380288] Memory state around the buggy address:
[  466.381844]  ffff888372139100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  466.384009]  ffff888372139180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  466.386131] >ffff888372139200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  466.388257]                                                  ^
[  466.390234]  ffff888372139280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  466.392512]  ffff888372139300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  466.394667] ==================================================================

tun_chr_read_iter() accessed the memory which freed by free_netdev()
called by tun_set_iff():

        CPUA                                           CPUB
  tun_set_iff()
    alloc_netdev_mqs()
    tun_attach()
                                                  tun_chr_read_iter()
                                                    tun_get()
                                                    tun_do_read()
                                                      tun_ring_recv()
    register_netdevice() <-- inject error
    goto err_detach
    tun_detach_all() <-- set RCV_SHUTDOWN
    free_netdev() <-- called from
                     err_free_dev path
      netdev_freemem() <-- free the memory
                        without check refcount
      (In this path, the refcount cannot prevent
       freeing the memory of dev, and the memory
       will be used by dev_put() called by
       tun_chr_read_iter() on CPUB.)
                                                     (Break from tun_ring_recv(),
                                                     because RCV_SHUTDOWN is set)
                                                   tun_put()
                                                     dev_put() <-- use the memory
                                                                   freed by netdev_freemem()

Put the publishing of tfile->tun after register_netdevice(),
so tun_get() won't get the tun pointer that freed by
err_detach path if register_netdevice() failed.

Fixes: eb0fb363f920 ("tuntap: attach queue 0 before registering netdevice")
Reported-by: Hulk Robot <hulkci@huawei.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>