Messages in this thread Patch in this message |  | | From | Artem Savkov <> | Subject | [PATCH] Fix suspicious RCU usage in nfs_idmap_get_key. | Date | Tue, 4 Oct 2016 15:37:40 +0200 |
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nfs_idmap_get_key doesn't hold rkey->sem when calling user_key_payload resulting in a "suspicious RCU usage" lockdep splat. It does, however hold rcu_read_lock, so it either needs to use unprotected rcu_dereference, or take rkey->sem instead of rcu_read_lock.
Signed-off-by: Artem Savkov <asavkov@redhat.com> --- fs/nfs/nfs4idmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/nfs4idmap.c b/fs/nfs/nfs4idmap.c index c444285..a67d1c0 100644 --- a/fs/nfs/nfs4idmap.c +++ b/fs/nfs/nfs4idmap.c @@ -309,7 +309,7 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen, goto out; } - rcu_read_lock(); + down_read(&rkey->sem); rkey->perm |= KEY_USR_VIEW; ret = key_validate(rkey); @@ -329,7 +329,7 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen, ret = -EINVAL; out_up: - rcu_read_unlock(); + up_read(&rkey->sem); key_put(rkey); out: return ret; -- 2.7.4
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