[PATCH RFC 01/24] filelock: push the S_ISREG check down to ->setlease handlers

Jeff Layton
2024-03-15T16:53:10Z

When nfsd starts requesting directory delegations, setlease handlers may
see requests for leases on directories. Push the !S_ISREG check down
into the non-trivial setlease handlers, so we can selectively enable
them where they're supported.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/locks.c | 5 +++--
fs/nfs/nfs4file.c | 2 ++
fs/smb/client/cifsfs.c | 3 +++
3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index 90c8746874de..cb4b35d26162 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1925,6 +1925,9 @@ static int generic_delete_lease(struct file *filp, void *owner)
int generic_setlease(struct file *filp, int arg, struct file_lease **flp,
void **priv)
{
+ if (!S_ISREG(file_inode(filp)->i_mode))
+ return -EINVAL;
+
switch (arg) {
case F_UNLCK:
return generic_delete_lease(filp, *priv);
@@ -2014,8 +2017,6 @@ vfs_setlease(struct file *filp, int arg, struct file_lease **lease, void **priv)

if ((!vfsuid_eq_kuid(vfsuid, current_fsuid())) && !capable(CAP_LEASE))
return -EACCES;
- if (!S_ISREG(inode->i_mode))
- return -EINVAL;
error = security_file_lock(filp, arg);
if (error)
return error;
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 1cd9652f3c28..b7630a437ad2 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -442,6 +442,8 @@ void nfs42_ssc_unregister_ops(void)
static int nfs4_setlease(struct file *file, int arg, struct file_lease **lease,
void **priv)
{
+ if (!S_ISREG(file_inode(file)->i_mode))
+ return -EINVAL;
return nfs4_proc_setlease(file, arg, lease, priv);
}

diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index fb368b191eef..81a96fbfa3ed 100644
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -1094,6 +1094,9 @@ cifs_setlease(struct file *file, int arg, struct file_lease **lease, void **priv
struct inode *inode = file_inode(file);
struct cifsFileInfo *cfile = file->private_data;

+ if (!S_ISREG(inode->i_mode))
+ return -EINVAL;
+
/* Check if file is oplocked if this is request for new lease */
if (arg == F_UNLCK ||
((arg == F_RDLCK) && CIFS_CACHE_READ(CIFS_I(inode))) ||

--
2.44.0