From: Seth Forshee <sforshee@xxxxxxxxxx>
commit 42d0c4bdf753063b6eec55415003184d3ca24f6e upstream.
A user should be allowed to take out a lease via an idmapped mount if
the fsuid matches the mapped uid of the inode. generic_setlease() is
checking the unmapped inode uid, causing these operations to be denied.
Fix this by comparing against the mapped inode uid instead of the
unmapped uid.
Fixes: 9caccd41541a ("fs: introduce MOUNT_ATTR_IDMAP")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@xxxxxxxxxx>
Signed-off-by: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/locks.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1862,9 +1862,10 @@ int generic_setlease(struct file *filp,
void **priv)
{
struct inode *inode = locks_inode(filp);
+ vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_user_ns(filp), inode);
int error;
- if ((!uid_eq(current_fsuid(), inode->i_uid)) && !capable(CAP_LEASE))
+ if ((!vfsuid_eq_kuid(vfsuid, current_fsuid())) && !capable(CAP_LEASE))
return -EACCES;
if (!S_ISREG(inode->i_mode))
return -EINVAL;
