diff options
| author | Trond Myklebust <trond.myklebust@hammerspace.com> | 2020-04-02 15:27:09 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2020-04-03 18:26:02 -0400 |
| commit | fc51b1cf391dd91ff9362861ed226ef51048e863 (patch) | |
| tree | 4b71836ccd7b74efcd72964427ab95389654e953 /fs/nfs/nfs4proc.c | |
| parent | f30a6ea0f3a582cea72b0373612d4b38f383fbd9 (diff) | |
NFS: Beware when dereferencing the delegation cred
When we look up the delegation cred, we are usually doing so in
conjunction with a read of the stateid, and we want to ensure
that the look up is atomic with that read.
Fixes: 57f188e04773 ("NFSv4: nfs_update_inplace_delegation() should update delegation cred")
[sfr@canb.auug.org.au: Fixed up borken Fixes: line from Trond :-)]
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Diffstat (limited to 'fs/nfs/nfs4proc.c')
| -rw-r--r-- | fs/nfs/nfs4proc.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 905c7d1bc277..e4f8311e506c 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2790,16 +2790,19 @@ static int nfs41_check_delegation_stateid(struct nfs4_state *state) return NFS_OK; } + spin_lock(&delegation->lock); nfs4_stateid_copy(&stateid, &delegation->stateid); if (!test_and_clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags)) { + spin_unlock(&delegation->lock); rcu_read_unlock(); return NFS_OK; } if (delegation->cred) cred = get_cred(delegation->cred); + spin_unlock(&delegation->lock); rcu_read_unlock(); status = nfs41_test_and_free_expired_stateid(server, &stateid, cred); trace_nfs4_test_delegation_stateid(state, NULL, status); |