From 2d8b3898caf5b4875e7319cd4d71b14c46bc0923 Mon Sep 17 00:00:00 2001 From: Scott Mayhew Date: Wed, 16 Apr 2025 11:23:38 -0400 Subject: [PATCH] NFSv4: xattr handlers should check for absent nfs filehandles [ Upstream commit 6e9a2f8dbe93c8004c2af2c0158888628b7ca034 ] The nfs inodes for referral anchors that have not yet been followed have their filehandles zeroed out. Attempting to call getxattr() on one of these will cause the nfs client to send a GETATTR to the nfs server with the preceding PUTFH sans filehandle. The server will reply NFS4ERR_NOFILEHANDLE, leading to -EIO being returned to the application. For example: $ strace -e trace=getxattr getfattr -n system.nfs4_acl /mnt/t/ref getxattr("/mnt/t/ref", "system.nfs4_acl", NULL, 0) = -1 EIO (Input/output error) /mnt/t/ref: system.nfs4_acl: Input/output error +++ exited with 1 +++ Have the xattr handlers return -ENODATA instead. Signed-off-by: Scott Mayhew Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin --- fs/nfs/nfs4proc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 97a009e007f9..3085a2faab2d 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -6059,6 +6059,8 @@ static ssize_t nfs4_proc_get_acl(struct inode *inode, void *buf, size_t buflen, struct nfs_server *server = NFS_SERVER(inode); int ret; + if (unlikely(NFS_FH(inode)->size == 0)) + return -ENODATA; if (!nfs4_server_supports_acls(server, type)) return -EOPNOTSUPP; ret = nfs_revalidate_inode(inode, NFS_INO_INVALID_CHANGE); @@ -6133,6 +6135,9 @@ static int nfs4_proc_set_acl(struct inode *inode, const void *buf, { struct nfs4_exception exception = { }; int err; + + if (unlikely(NFS_FH(inode)->size == 0)) + return -ENODATA; do { err = __nfs4_proc_set_acl(inode, buf, buflen, type); trace_nfs4_set_acl(inode, err);