[PATCH 6.1 407/473] NFSv4: Fixup smatch warning for ambiguous return

Greg Kroah-Hartman
2024-06-06T14:18:49Z

From: Benjamin Coddington <bcodding@redhat.com>

[ Upstream commit 37ffe06537af3e3ec212e7cbe941046fce0a822f ]

Dan Carpenter reports smatch warning for nfs4_try_migration() when a memory
allocation failure results in a zero return value. In this case, a
transient allocation failure error will likely be retried the next time the
server responds with NFS4ERR_MOVED.

We can fixup the smatch warning with a small refactor: attempt all three
allocations before testing and returning on a failure.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: c3ed222745d9 ("NFSv4: Fix free of uninitialized nfs4_label on referral lookup.")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/nfs4state.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 457b2b2f804ab..2b19ddc2c39ad 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -2113,6 +2113,7 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred
{
struct nfs_client *clp = server->nfs_client;
struct nfs4_fs_locations *locations = NULL;
+ struct nfs_fattr *fattr;
struct inode *inode;
struct page *page;
int status, result;
@@ -2122,19 +2123,16 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred
(unsigned long long)server->fsid.minor,
clp->cl_hostname);

- result = 0;
page = alloc_page(GFP_KERNEL);
locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
- if (page == NULL || locations == NULL) {
- dprintk("<-- %s: no memory\n", __func__);
- goto out;
- }
- locations->fattr = nfs_alloc_fattr();
- if (locations->fattr == NULL) {
+ fattr = nfs_alloc_fattr();
+ if (page == NULL || locations == NULL || fattr == NULL) {
dprintk("<-- %s: no memory\n", __func__);
+ result = 0;
goto out;
}

+ locations->fattr = fattr;
inode = d_inode(server->super->s_root);
result = nfs4_proc_get_locations(server, NFS_FH(inode), locations,
page, cred);
--
2.43.0