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authorMike Snitzer <snitzer@kernel.org>2024-10-03 15:34:58 -0400
committerAnna Schumaker <anna.schumaker@oracle.com>2024-10-03 16:19:43 -0400
commit65f2a5c366353da6fa724c68347e1de954928143 (patch)
tree3dbc942931e5b9c55c54519e9fcf846b841cd8be /fs/nfs
parenta848c29e3486189aaabd5663bc11aea50c5bd144 (diff)
nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()
Add nfs_to_nfsd_file_put_local() interface to fix race with nfsd module unload. Similarly, use RCU around nfs_open_local_fh()'s error path call to nfs_to->nfsd_serv_put(). Holding RCU ensures that NFS will safely _call and return_ from its nfs_to calls into the NFSD functions nfsd_file_put_local() and nfsd_serv_put(). Otherwise, if RCU isn't used then there is a narrow window when NFS's reference for the nfsd_file and nfsd_serv are dropped and the NFSD module could be unloaded, which could result in a crash from the return instruction for either nfs_to->nfsd_file_put_local() or nfs_to->nfsd_serv_put(). Reported-by: NeilBrown <neilb@suse.de> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/localio.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index c5922b1a77c0..d0aa680ec816 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -340,7 +340,7 @@ nfs_local_pgio_release(struct nfs_local_kiocb *iocb)
{
struct nfs_pgio_header *hdr = iocb->hdr;
- nfs_to->nfsd_file_put_local(iocb->localio);
+ nfs_to_nfsd_file_put_local(iocb->localio);
nfs_local_iocb_free(iocb);
nfs_local_hdr_release(hdr, hdr->task.tk_ops);
}
@@ -621,7 +621,7 @@ int nfs_local_doio(struct nfs_client *clp, struct nfsd_file *localio,
}
out:
if (status != 0) {
- nfs_to->nfsd_file_put_local(localio);
+ nfs_to_nfsd_file_put_local(localio);
hdr->task.tk_status = status;
nfs_local_hdr_release(hdr, call_ops);
}
@@ -672,7 +672,7 @@ nfs_local_release_commit_data(struct nfsd_file *localio,
struct nfs_commit_data *data,
const struct rpc_call_ops *call_ops)
{
- nfs_to->nfsd_file_put_local(localio);
+ nfs_to_nfsd_file_put_local(localio);
call_ops->rpc_call_done(&data->task, data);
call_ops->rpc_release(data);
}