From 6e9a2f8dbe93c8004c2af2c0158888628b7ca034 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 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 --- fs/nfs/nfs4proc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index b1d2122bd5a74..f837ed7ad90c0 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -6211,6 +6211,8 @@ 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); @@ -6285,6 +6287,9 @@ 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); -- 2.47.2