[PATCH] fix for initrd panic in 2.4.5

[James Bottomley]

Not many people have seen this, but the i_bdev field in fake_inode in 
ioctl_by_bdev() is uninitialised.  Since this field is dereferenced by 
BLKFLSBUF in rd_ioctl, it can lead to a panic (depending on what happens to be 
on the stack).  The attached fixes the problem and clears all the fields in 
fake_inode to make any other problems like this show up.

James Bottomley


Index: fs/block_dev.c
===================================================================
RCS file: /home/jejb/CVSROOT/linux/2.4/fs/block_dev.c,v
retrieving revision 1.1.1.10
diff -u -r1.1.1.10 block_dev.c
--- fs/block_dev.c      2001/05/26 15:33:37     1.1.1.10
+++ fs/block_dev.c      2001/06/02 13:14:35
@@ -596,13 +596,14 @@
 int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)
 {
        kdev_t rdev = to_kdev_t(bdev->bd_dev);
-       struct inode inode_fake;
+       struct inode inode_fake = { 0 };
        int res;
        mm_segment_t old_fs = get_fs();
 
        if (!bdev->bd_op->ioctl)
                return -EINVAL;
        inode_fake.i_rdev=rdev;
+       inode_fake.i_bdev = bdev;
        init_waitqueue_head(&inode_fake.i_wait);
        set_fs(KERNEL_DS);
        res = bdev->bd_op->ioctl(&inode_fake, NULL, cmd, arg);