From: Christoph Hellwig <hch@lst.de>
Date: Fri, 1 Oct 2010 03:41:27 +0000 (+0200)
Subject: hfsplus: fix BKL leak in hfsplus_ioctl
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=249e6353001e407edf5c9a74482ecfca90c8ff33;p=openwrt%2Fstaging%2Fblogic.git

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>
---

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;
 	}
 }