fs: add missing compat_ptr handling for FS_IOC_RESVSP ioctl

For FS_IOC_RESVSP and FS_IOC_RESVSP64 compat_sys_ioctl() uses its
arg argument as a pointer to userspace. However it is missing a
a call to compat_ptr() which will do a proper pointer conversion.

This was introduced with 3e63cbb1 "fs: Add new pre-allocation ioctls
to vfs for compatibility with legacy xfs ioctls".

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ankit Jain <me@ankitjain.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Arnd Bergmann <arndbergmann@googlemail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: <stable@kernel.org>		[2.6.31.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index f91fd51b32e3..d84e7058c298 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -1800,7 +1800,7 @@ struct space_resv_32 {
 /* just account for different alignment */
 static int compat_ioctl_preallocate(struct file *file, unsigned long arg)
 {
-        struct space_resv_32    __user *p32 = (void __user *)arg;
+        struct space_resv_32    __user *p32 = compat_ptr(arg);
         struct space_resv       __user *p = compat_alloc_user_space(sizeof(*p));
 
         if (copy_in_user(&p->l_type,    &p32->l_type,   sizeof(s16)) ||
@@ -2802,7 +2802,7 @@ asmlinkage long compat_sys_ioctl(unsigned int fd, unsigned int cmd,
 #else
         case FS_IOC_RESVSP:
         case FS_IOC_RESVSP64:
-                error = ioctl_preallocate(filp, (void __user *)arg);
+                error = ioctl_preallocate(filp, compat_ptr(arg));
                 goto out_fput;
 #endif