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| author |   Nikolay Aleksandrov <nikolay@nvidia.com> | 2021-08-05 11:29:01 +0300 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2021-08-05 11:36:59 +0100 |
| commit | 893b195875340cb44b54c9db99e708145f1210e8 (patch) | |
| tree | f5d98a9ed881302ccbbb53865b82f7d7e9fb8b6a /net/bridge/br_if.c | |
| parent | net/ipv4: Revert use of struct_size() helper (diff) | |
| download | linux-dev-893b195875340cb44b54c9db99e708145f1210e8.tar.xz linux-dev-893b195875340cb44b54c9db99e708145f1210e8.zip | |
net: bridge: fix ioctl locking
Before commit ad2f99aedf8f ("net: bridge: move bridge ioctls out of
.ndo_do_ioctl") the bridge ioctl calls were divided in two parts:
one was deviceless called by sock_ioctl and didn't expect rtnl to be held,
the other was with a device called by dev_ifsioc() and expected rtnl to be
held. After the commit above they were united in a single ioctl stub, but
it didn't take care of the locking expectations.
For sock_ioctl now we acquire (1) br_ioctl_mutex, (2) rtnl
and for dev_ifsioc we acquire (1) rtnl, (2) br_ioctl_mutex
The fix is to get a refcnt on the netdev for dev_ifsioc calls and drop rtnl
then to reacquire it in the bridge ioctl stub after br_ioctl_mutex has
been acquired. That will avoid playing locking games and make the rules
straight-forward: we always take br_ioctl_mutex first, and then rtnl.
Reported-by: syzbot+34fe5894623c4ab1b379@syzkaller.appspotmail.com
Fixes: ad2f99aedf8f ("net: bridge: move bridge ioctls out of .ndo_do_ioctl")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge/br_if.c')
| -rw-r--r-- | net/bridge/br_if.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index 86f6d7e93ea8..67c60240b713 100644 --- a/net/bridge/br_if.c +++ b/net/bridge/br_if.c @@ -456,7 +456,7 @@ int br_add_bridge(struct net *net, const char *name) dev_net_set(dev, net); dev->rtnl_link_ops = &br_link_ops; - res = register_netdev(dev); + res = register_netdevice(dev); if (res) free_netdev(dev); return res; @@ -467,7 +467,6 @@ int br_del_bridge(struct net *net, const char *name) struct net_device *dev; int ret = 0; - rtnl_lock(); dev = __dev_get_by_name(net, name); if (dev == NULL) ret = -ENXIO; /* Could not find device */ @@ -485,7 +484,6 @@ int br_del_bridge(struct net *net, const char *name) else br_dev_delete(dev, NULL); - rtnl_unlock(); return ret; } |