FIGETBSZ has an ioctl number of _IO(0x00,2) == 2, which can conflict
with device driver ioctls. Let's avoid the potential for problems by
only honoring the ioctl number for files where this ioctl is likely
going to be useful: regular files, directories, and symlinks.
Thanks to Johannes Stezenbach for pointing this consequence of commit
19ba0559.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Johannes Stezenbach <js@sig21.net>
---
fs/compat_ioctl.c | 6 +++++-
fs/ioctl.c | 5 ++++-
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index 641640d..b8607fe 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -1715,8 +1715,12 @@ asmlinkage long compat_sys_ioctl(unsigned int fd, unsigned int cmd,
goto out_fput;
#endif
- case FIBMAP:
case FIGETBSZ:
+ if (S_ISDIR(filp->f_path.dentry->d_inode->i_mode))
+ break;
+ /*FALL THROUGH */
+
+ case FIBMAP:
case FIONREAD:
if (S_ISREG(filp->f_path.dentry->d_inode->i_mode))
break;
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 2d140a7..e578dab 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -597,7 +597,10 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
{
struct inode *inode = filp->f_path.dentry->d_inode;
int __user *p = (int __user *)arg;
- return put_user(inode->i_sb->s_blocksize, p);
+
+ if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))
+ return put_user(inode->i_sb->s_blocksize, p);
+ /* FALL THROUGH */
}
default:
--
1.7.0.4
--
