[PATCH] NFSv4: Restore nfs4_label into copied nfs_fattr for referrals

From: Benjamin Coddington <bcodding@redhat.com>
To: trond.myklebust@hammerspace.com, anna@kernel.org
Cc: linux-nfs@vger.kernel.org, smayhew@redhat.com
Subject: [PATCH] NFSv4: Restore nfs4_label into copied nfs_fattr for referrals
Date: Fri, 13 May 2022 09:36:08 -0400	[thread overview]
Message-ID: <8ffe993a7aa39881d3e610d5424098ea7ec88180.1652448889.git.bcodding@redhat.com> (raw)

..which will fix up trying to free uninitialized nfs4_label:

PID: 790    TASK: ffff88811b43c000  CPU: 0   COMMAND: "ls"
 #0 [ffffc90000857920] panic at ffffffff81b9bfde
 #1 [ffffc900008579c0] do_trap at ffffffff81023a9b
 #2 [ffffc90000857a10] do_error_trap at ffffffff81023b78
 #3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45
 #4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de
 #5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs]
 #6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f
 #7 [ffffc90000857c60] walk_component at ffffffff813a86c4
 #8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553
 #9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b

Fixes: 9558a007dbc3 ("NFS: Remove the label from the nfs4_lookup_res struct")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
---
 fs/nfs/nfs4proc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index a79f66432bd3..4566280e6ff2 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4235,6 +4235,7 @@ static int nfs4_get_referral(struct rpc_clnt *client, struct inode *dir,
 	int status = -ENOMEM;
 	struct page *page = NULL;
 	struct nfs4_fs_locations *locations = NULL;
+	struct nfs4_label *label = fattr->label;
 
 	page = alloc_page(GFP_KERNEL);
 	if (page == NULL)
@@ -4263,6 +4264,7 @@ static int nfs4_get_referral(struct rpc_clnt *client, struct inode *dir,
 
 	/* replace the lookup nfs_fattr with the locations nfs_fattr */
 	memcpy(fattr, &locations->fattr, sizeof(struct nfs_fattr));
+	fattr->label = label;
 	memset(fhandle, 0, sizeof(struct nfs_fh));
 out:
 	if (page)
-- 
2.31.1

