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[NET]: Take dev_base_lock when moving device name hash list entry
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When we added name-based hashing the dev_base_lock was designated as the
lock to take when changing the name hash list.  Unfortunately, because
it was a preexisting lock that just happened to be taken in the right
spots we neglected to take it in dev_change_name.

The race can affect calles of __dev_get_by_name that do so without taking
the RTNL.  They may end up walking down the wrong hash chain and end up
missing the device that they're looking for.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Herbert Xu authored and David S. Miller committed Jul 31, 2007
1 parent 7ce1b0e commit 7f988ea
Showing 1 changed file with 4 additions and 0 deletions.
4 changes: 4 additions & 0 deletions net/core/dev.c
Original file line number Diff line number Diff line change
Expand Up @@ -839,8 +839,12 @@ int dev_change_name(struct net_device *dev, char *newname)
strlcpy(dev->name, newname, IFNAMSIZ);

device_rename(&dev->dev, dev->name);

write_lock_bh(&dev_base_lock);
hlist_del(&dev->name_hlist);
hlist_add_head(&dev->name_hlist, dev_name_hash(dev->name));
write_unlock_bh(&dev_base_lock);

raw_notifier_call_chain(&netdev_chain, NETDEV_CHANGENAME, dev);

return err;
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