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")
Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@xxxxxxxxxx>
---
fs/locks.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/locks.c b/fs/locks.c
index 66b4eef09db5..cf07f72eaf45 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1863,9 +1863,10 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp,
void **priv)
{
struct inode *inode = file_inode(filp);
+ vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_idmap(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;
---
base-commit: fe15c26ee26efa11741a7b632e9f23b01aca4cc6
change-id: 20230309-generic_setlease-use-idmapping-34e099aa2206
Best regards,
--
Seth Forshee (DigitalOcean) <sforshee@xxxxxxxxxx>
