diff options
| author | Trond Myklebust <trond.myklebust@hammerspace.com> | 2024-11-08 12:13:31 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-12-05 13:54:27 +0100 |
| commit | e2277a1d9d5cd0d625a4fd7c04fce2b53e66df77 (patch) | |
| tree | da99fd6ff7e67477177cb39d860336f34cf816cf | |
| parent | 7e8cf283d25f3acf247d6e2d5f72f0a07db81ada (diff) | |
NFSv4.0: Fix a use-after-free problem in the asynchronous open()
[ Upstream commit 2fdb05dc0931250574f0cb0ebeb5ed8e20f4a889 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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; |