1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017 Oracle.  All Rights Reserved.
4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_trans_resv.h"
11 #include "xfs_mount.h"
12 #include "xfs_defer.h"
13 #include "xfs_btree.h"
14 #include "xfs_bit.h"
15 #include "xfs_log_format.h"
16 #include "xfs_trans.h"
17 #include "xfs_sb.h"
18 #include "xfs_inode.h"
19 #include "xfs_inode_fork.h"
20 #include "xfs_symlink.h"
21 #include "scrub/xfs_scrub.h"
22 #include "scrub/scrub.h"
23 #include "scrub/common.h"
24 #include "scrub/trace.h"
25 
26 /* Set us up to scrub a symbolic link. */
27 int
xchk_setup_symlink(struct xfs_scrub * sc,struct xfs_inode * ip)28 xchk_setup_symlink(
29 	struct xfs_scrub	*sc,
30 	struct xfs_inode	*ip)
31 {
32 	/* Allocate the buffer without the inode lock held. */
33 	sc->buf = kmem_zalloc_large(XFS_SYMLINK_MAXLEN + 1, KM_SLEEP);
34 	if (!sc->buf)
35 		return -ENOMEM;
36 
37 	return xchk_setup_inode_contents(sc, ip, 0);
38 }
39 
40 /* Symbolic links. */
41 
42 int
xchk_symlink(struct xfs_scrub * sc)43 xchk_symlink(
44 	struct xfs_scrub	*sc)
45 {
46 	struct xfs_inode	*ip = sc->ip;
47 	struct xfs_ifork	*ifp;
48 	loff_t			len;
49 	int			error = 0;
50 
51 	if (!S_ISLNK(VFS_I(ip)->i_mode))
52 		return -ENOENT;
53 	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
54 	len = ip->i_d.di_size;
55 
56 	/* Plausible size? */
57 	if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
58 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
59 		goto out;
60 	}
61 
62 	/* Inline symlink? */
63 	if (ifp->if_flags & XFS_IFINLINE) {
64 		if (len > XFS_IFORK_DSIZE(ip) ||
65 		    len > strnlen(ifp->if_u1.if_data, XFS_IFORK_DSIZE(ip)))
66 			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
67 		goto out;
68 	}
69 
70 	/* Remote symlink; must read the contents. */
71 	error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
72 	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
73 		goto out;
74 	if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
75 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
76 out:
77 	return error;
78 }
79