hfsplus: fix BKL leak in hfsplus_ioctl

Currenly the HFSPLUS_IOC_EXT2_GETFLAGS case never unlocks the BKL, which
can lead to easily reproduced lockups when doing multiple GETFLAGS ioctls.

Fix this by only taking the BKL for the HFSPLUS_IOC_EXT2_SETFLAGS case
as neither HFSPLUS_IOC_EXT2_GETFLAGS not the default error case needs it.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/hfsplus/ioctl.c b/fs/hfsplus/ioctl.c
index ac405f099026..59dc402dfe95 100644
--- a/fs/hfsplus/ioctl.c
+++ b/fs/hfsplus/ioctl.c
@@ -26,7 +26,6 @@ long hfsplus_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
         struct inode *inode = filp->f_path.dentry->d_inode;
         unsigned int flags;
 
-        lock_kernel();
         switch (cmd) {
         case HFSPLUS_IOC_EXT2_GETFLAGS:
                 flags = 0;
@@ -39,6 +38,8 @@ long hfsplus_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                 return put_user(flags, (int __user *)arg);
         case HFSPLUS_IOC_EXT2_SETFLAGS: {
                 int err = 0;
+
+                lock_kernel();
                 err = mnt_want_write(filp->f_path.mnt);
                 if (err) {
                         unlock_kernel();
@@ -93,7 +94,6 @@ setflags_out:
                 return err;
         }
         default:
-                unlock_kernel();
                 return -ENOTTY;
         }
 }