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Commit ecaff756 authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
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[PATCH] knfsd: Have ext2 reject file handles with bad inode numbers early 



This prevents bad inode numbers from triggering errors in ext2_get_inode.

[akpm@osdl.org: speedup, cleanup]
Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 55ebcc38

fs/ext2/super.c

+39 −0
Original line number Diff line number Diff line
@@ -251,6 +251,44 @@ static struct super_operations ext2_sops = { 
#endif

};



static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)

{

	__u32 *objp = vobjp;

	unsigned long ino = objp[0];

	__u32 generation = objp[1];

	struct inode *inode;

	struct dentry *result;



	if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)

		return ERR_PTR(-ESTALE);

	if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))

		return ERR_PTR(-ESTALE);



	/* iget isn't really right if the inode is currently unallocated!!

	 * ext2_read_inode currently does appropriate checks, but

	 * it might be "neater" to call ext2_get_inode first and check

	 * if the inode is valid.....

	 */

	inode = iget(sb, ino);

	if (inode == NULL)

		return ERR_PTR(-ENOMEM);

	if (is_bad_inode(inode) ||

	    (generation && inode->i_generation != generation)) {

		/* we didn't find the right inode.. */

		iput(inode);

		return ERR_PTR(-ESTALE);

	}

	/* now to find a dentry.

	 * If possible, get a well-connected one

	 */

	result = d_alloc_anon(inode);

	if (!result) {

		iput(inode);

		return ERR_PTR(-ENOMEM);

	}

	return result;

}



/* Yes, most of these are left as NULL!!

 * A NULL value implies the default, which works with ext2-like file

 * systems, but can be improved upon.
@@ -258,6 +296,7 @@ static struct super_operations ext2_sops = { 
 */

static struct export_operations ext2_export_ops = {

	.get_parent = ext2_get_parent,

	.get_dentry = ext2_get_dentry,

};



static unsigned long get_sb_block(void **data)