diff options
| author | Trond Myklebust <trond.myklebust@hammerspace.com> | 2024-11-08 12:13:31 -0500 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2024-11-09 11:01:35 -0500 |
| commit | 2fdb05dc0931250574f0cb0ebeb5ed8e20f4a889 (patch) | |
| tree | 9d16fa0c4294a128a9331e3a9fe50d318213053f /fs/nfs | |
| parent | c968fd23c68e9929ab6cad4faffc8ea603e98e5d (diff) | |
NFSv4.0: Fix a use-after-free problem in the asynchronous open()
Yang Erkun reports that when two threads are opening files at the same
time, and are forced to abort before a reply is seen, then the call to
nfs_release_seqid() in nfs4_opendata_free() can result in a
use-after-free of the pointer to the defunct rpc task of the other
thread.
The fix is to ensure that if the RPC call is aborted before the call to
nfs_wait_on_sequence() is complete, then we must call nfs_release_seqid()
in nfs4_open_release() before the rpc_task is freed.
Reported-by: Yang Erkun <yangerkun@huawei.com>
Fixes: 24ac23ab88df ("NFSv4: Convert open() into an asynchronous RPC call")
Reviewed-by: Yang Erkun <yangerkun@huawei.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, 5 insertions, 3 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 9d40319e063d..405f17e6e0b4 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2603,12 +2603,14 @@ static void nfs4_open_release(void *calldata) struct nfs4_opendata *data = calldata; struct nfs4_state *state = NULL; + /* In case of error, no cleanup! */ + if (data->rpc_status != 0 || !data->rpc_done) { + nfs_release_seqid(data->o_arg.seqid); + goto out_free; + } /* If this request hasn't been cancelled, do nothing */ if (!data->cancelled) goto out_free; - /* In case of error, no cleanup! */ - if (data->rpc_status != 0 || !data->rpc_done) - goto out_free; /* In case we need an open_confirm, no cleanup! */ if (data->o_res.rflags & NFS4_OPEN_RESULT_CONFIRM) goto out_free; |