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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2015-03-15 21:12:04 +1100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-03-15 22:22:08 -0400 |
| commit | 963ecbd41a1026d99ec7537c050867428c397b89 (patch) | |
| tree | b1735fd0d424222d31fb72f51d860b51e417dac5 /lib | |
| parent | 0034de4193e4aad30bbbef4e74ca5e0631ba08a7 (diff) | |
| download | linux-963ecbd41a1026d99ec7537c050867428c397b89.tar.bz2 | |
rhashtable: Fix use-after-free in rhashtable_walk_stop
The commit c4db8848af6af92f90462258603be844baeab44d ("rhashtable:
Move future_tbl into struct bucket_table") introduced a use-after-
free bug in rhashtable_walk_stop because it dereferences tbl after
droping the RCU read lock.
This patch fixes it by moving the RCU read unlock down to the bottom
of rhashtable_walk_stop. In fact this was how I had it originally
but it got dropped while rearranging patches because this one
depended on the async freeing of bucket_table.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/rhashtable.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/lib/rhashtable.c b/lib/rhashtable.c index 9d53a46dcca9..b916679b3e3b 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -854,10 +854,8 @@ void rhashtable_walk_stop(struct rhashtable_iter *iter) struct rhashtable *ht; struct bucket_table *tbl = iter->walker->tbl; - rcu_read_unlock(); - if (!tbl) - return; + goto out; ht = iter->ht; @@ -869,6 +867,9 @@ void rhashtable_walk_stop(struct rhashtable_iter *iter) mutex_unlock(&ht->mutex); iter->p = NULL; + +out: + rcu_read_unlock(); } EXPORT_SYMBOL_GPL(rhashtable_walk_stop); |