diff options
| author | Ruoyu Wang <ruoyuw560@gmail.com> | 2026-06-24 11:58:58 +0800 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2026-08-17 09:02:07 -0700 |
| commit | d05c2007b3d84ccba11dc6e9cb3202768cc72f14 (patch) | |
| tree | cb904341177ac4821377ac7408c4d787217148bc | |
| parent | 187bfc974eefa9e5d88a0b4ee9d08ae8fe485df4 (diff) | |
NFSv4: remove callback IDR entry on client allocation failure
nfs4_alloc_client() allocates an NFSv4.0 callback identifier before it
finishes setting up the client. If any later initialization step fails,
the error path frees the nfs_client directly with nfs_free_client(). That
bypasses nfs_put_client(), which is where the callback IDR entry is
removed during normal teardown.
A failed allocation can therefore leave cb_ident_idr pointing at a freed
nfs_client. A later NFSv4.0 callback lookup by cb_ident would find the
stale pointer and take a reference to it.
Make the callback IDR removal helper callable by the allocation failure
path, and remove the callback identifier before freeing the client.
This was found by a local static-analysis checker for publish-before-free
lifetime bugs and confirmed by manual inspection.
Fixes: f4eecd5da342 ("NFS implement v4.0 callback_ident")
Signed-off-by: Ruoyu Wang <ruoyuw560@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
| -rw-r--r-- | fs/nfs/client.c | 14 | ||||
| -rw-r--r-- | fs/nfs/internal.h | 1 | ||||
| -rw-r--r-- | fs/nfs/nfs4client.c | 1 |
3 files changed, 15 insertions, 1 deletions
diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 4dcb91ab3039..60386330aeec 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -215,9 +215,21 @@ static void nfs_cb_idr_remove_locked(struct nfs_client *clp) { struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id); - if (clp->cl_cb_ident) + if (clp->cl_cb_ident) { idr_remove(&nn->cb_ident_idr, clp->cl_cb_ident); + clp->cl_cb_ident = 0; + } +} + +void nfs_cb_idr_remove(struct nfs_client *clp) +{ + struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id); + + spin_lock(&nn->nfs_client_lock); + nfs_cb_idr_remove_locked(clp); + spin_unlock(&nn->nfs_client_lock); } +EXPORT_SYMBOL_GPL(nfs_cb_idr_remove); static void pnfs_init_server(struct nfs_server *server) { diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index e4533f583632..864fa092bcea 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -225,6 +225,7 @@ void nfs_server_copy_userdata(struct nfs_server *, struct nfs_server *); extern void nfs_put_client(struct nfs_client *); extern void nfs_free_client(struct nfs_client *); +void nfs_cb_idr_remove(struct nfs_client *clp); extern struct nfs_client *nfs4_find_client_ident(struct net *, int); extern struct nfs_client * nfs4_find_client_sessionid(struct net *, const struct sockaddr *, diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c index 71c271a1700a..aff019d2842d 100644 --- a/fs/nfs/nfs4client.c +++ b/fs/nfs/nfs4client.c @@ -261,6 +261,7 @@ struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init) return clp; error: + nfs_cb_idr_remove(clp); nfs_free_client(clp); return ERR_PTR(err); } |