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| author | Scott Mayhew <smayhew@redhat.com> | 2021-11-03 11:24:40 +0100 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2021-11-03 13:47:51 +0100 |
| commit | 576acc259146af848cec0940f573f7125a116b9f (patch) | |
| tree | fbc8c76b6b3c63888bc8457725da1506da41af11 /fs/nfs | |
| parent | NFS: Add offset to nfs_aop_readahead tracepoint (diff) | |
| download | linux-576acc259146af848cec0940f573f7125a116b9f.tar.xz linux-576acc259146af848cec0940f573f7125a116b9f.zip | |
nfs4: take a reference on the nfs_client when running FREE_STATEID
During umount, the session slot tables are freed. If there are
outstanding FREE_STATEID tasks, a use-after-free and slab corruption can
occur when rpc_exit_task calls rpc_call_done -> nfs41_sequence_done ->
nfs4_sequence_process/nfs41_sequence_free_slot.
Prevent that from happening by taking a reference on the nfs_client in
nfs41_free_stateid and putting it in nfs41_free_stateid_release.
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/nfs4proc.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 1c94f54cab58..127388fabda8 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -10115,6 +10115,10 @@ static void nfs41_free_stateid_done(struct rpc_task *task, void *calldata) static void nfs41_free_stateid_release(void *calldata) { + struct nfs_free_stateid_data *data = calldata; + struct nfs_client *clp = data->server->nfs_client; + + nfs_put_client(clp); kfree(calldata); } @@ -10151,6 +10155,10 @@ static int nfs41_free_stateid(struct nfs_server *server, }; struct nfs_free_stateid_data *data; struct rpc_task *task; + struct nfs_client *clp = server->nfs_client; + + if (!refcount_inc_not_zero(&clp->cl_count)) + return -EIO; nfs4_state_protect(server->nfs_client, NFS_SP4_MACH_CRED_STATEID, &task_setup.rpc_client, &msg); |