Commit Graph

5 Commits

Author SHA1 Message Date
Oleksij Rempel feaa85d4b9 net: introduce CAN specific pointer in the struct net_device
[ Upstream commit 4e096a18867a5a989b510f6999d9c6b6622e8f7b ]

Since 20dd3850bcf8 ("can: Speed up CAN frame receiption by using
ml_priv") the CAN framework uses per device specific data in the AF_CAN
protocol. For this purpose the struct net_device->ml_priv is used. Later
the ml_priv usage in CAN was extended for other users, one of them being
CAN_J1939.

Later in the kernel ml_priv was converted to an union, used by other
drivers. E.g. the tun driver started storing it's stats pointer.

Since tun devices can claim to be a CAN device, CAN specific protocols
will wrongly interpret this pointer, which will cause system crashes.
Mostly this issue is visible in the CAN_J1939 stack.

To fix this issue, we request a dedicated CAN pointer within the
net_device struct.

Reported-by: syzbot+5138c4dd15a0401bec7b@syzkaller.appspotmail.com
Fixes: 20dd3850bcf8 ("can: Speed up CAN frame receiption by using ml_priv")
Fixes: ffd956eef69b ("can: introduce CAN midlayer private and allocate it automatically")
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Fixes: 497a5757ce4e ("tun: switch to net core provided statistics counters")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20210223070127.4538-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-20 16:06:48 +08:00
Cong Wang 7f1af5b7d8 net: fix dev_ifsioc_locked() race condition
commit 3b23a32a63219f51a5298bc55a65ecee866e79d0 upstream.

dev_ifsioc_locked() is called with only RCU read lock, so when
there is a parallel writer changing the mac address, it could
get a partially updated mac address, as shown below:

Thread 1			Thread 2
// eth_commit_mac_addr_change()
memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
				// dev_ifsioc_locked()
				memcpy(ifr->ifr_hwaddr.sa_data,
					dev->dev_addr,...);

Close this race condition by guarding them with a RW semaphore,
like netdev_get_name(). We can not use seqlock here as it does not
allow blocking. The writers already take RTNL anyway, so this does
not affect the slow path. To avoid bothering existing
dev_set_mac_address() callers in drivers, introduce a new wrapper
just for user-facing callers on ioctl and rtnetlink paths.

Note, bonding also changes slave mac addresses but that requires
a separate patch due to the complexity of bonding code.

Fixes: 3710becf8a58 ("net: RCU locking for simple ioctl()")
Reported-by: "Gong, Sishuai" <sishuai@purdue.edu>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-12 12:52:45 +08:00
Edwin Peer c7b6692299 net: watchdog: hold device global xmit lock during tx disable
commit 3aa6bce9af0e25b735c9c1263739a5639a336ae8 upstream.

Prevent netif_tx_disable() running concurrently with dev_watchdog() by
taking the device global xmit lock. Otherwise, the recommended:

	netif_carrier_off(dev);
	netif_tx_disable(dev);

driver shutdown sequence can happen after the watchdog has already
checked carrier, resulting in possible false alarms. This is because
netif_tx_lock() only sets the frozen bit without maintaining the locks
on the individual queues.

Fixes: c3f26a269c24 ("netdev: Fix lockdep warnings in multiqueue configurations.")
Signed-off-by: Edwin Peer <edwin.peer@broadcom.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-12 12:52:06 +08:00
Taehee Yoo 2e4049428a net: core: reduce recursion limit value
[ Upstream commit fb7861d14c8d7edac65b2fcb6e8031cb138457b2 ]

In the current code, ->ndo_start_xmit() can be executed recursively only
10 times because of stack memory.
But, in the case of the vxlan, 10 recursion limit value results in
a stack overflow.
In the current code, the nested interface is limited by 8 depth.
There is no critical reason that the recursion limitation value should
be 10.
So, it would be good to be the same value with the limitation value of
nesting interface depth.

Test commands:
    ip link add vxlan10 type vxlan vni 10 dstport 4789 srcport 4789 4789
    ip link set vxlan10 up
    ip a a 192.168.10.1/24 dev vxlan10
    ip n a 192.168.10.2 dev vxlan10 lladdr fc:22:33:44:55:66 nud permanent

    for i in {9..0}
    do
        let A=$i+1
	ip link add vxlan$i type vxlan vni $i dstport 4789 srcport 4789 4789
	ip link set vxlan$i up
	ip a a 192.168.$i.1/24 dev vxlan$i
	ip n a 192.168.$i.2 dev vxlan$i lladdr fc:22:33:44:55:66 nud permanent
	bridge fdb add fc:22:33:44:55:66 dev vxlan$A dst 192.168.$i.2 self
    done
    hping3 192.168.10.2 -2 -d 60000

Splat looks like:
[  103.814237][ T1127] =============================================================================
[  103.871955][ T1127] BUG kmalloc-2k (Tainted: G    B            ): Padding overwritten. 0x00000000897a2e4f-0x000
[  103.873187][ T1127] -----------------------------------------------------------------------------
[  103.873187][ T1127]
[  103.874252][ T1127] INFO: Slab 0x000000005cccc724 objects=5 used=5 fp=0x0000000000000000 flags=0x10000000001020
[  103.881323][ T1127] CPU: 3 PID: 1127 Comm: hping3 Tainted: G    B             5.7.0+ #575
[  103.882131][ T1127] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  103.883006][ T1127] Call Trace:
[  103.883324][ T1127]  dump_stack+0x96/0xdb
[  103.883716][ T1127]  slab_err+0xad/0xd0
[  103.884106][ T1127]  ? _raw_spin_unlock+0x1f/0x30
[  103.884620][ T1127]  ? get_partial_node.isra.78+0x140/0x360
[  103.885214][ T1127]  slab_pad_check.part.53+0xf7/0x160
[  103.885769][ T1127]  ? pskb_expand_head+0x110/0xe10
[  103.886316][ T1127]  check_slab+0x97/0xb0
[  103.886763][ T1127]  alloc_debug_processing+0x84/0x1a0
[  103.887308][ T1127]  ___slab_alloc+0x5a5/0x630
[  103.887765][ T1127]  ? pskb_expand_head+0x110/0xe10
[  103.888265][ T1127]  ? lock_downgrade+0x730/0x730
[  103.888762][ T1127]  ? pskb_expand_head+0x110/0xe10
[  103.889244][ T1127]  ? __slab_alloc+0x3e/0x80
[  103.889675][ T1127]  __slab_alloc+0x3e/0x80
[  103.890108][ T1127]  __kmalloc_node_track_caller+0xc7/0x420
[ ... ]

Fixes: 11a766ce915f ("net: Increase xmit RECURSION_LIMIT to 10.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:30:46 +08:00
Kaixu Xia 590eaf1fec Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
2021-03-16 11:01:34 +08:00