[PATCH 4.9 73/94] xfs: rework the inline directory verifiers

From: Greg Kroah-Hartman
Date: Mon Jun 05 2017 - 12:59:26 EST

4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

commit 78420281a9d74014af7616958806c3aba056319e upstream.

The inline directory verifiers should be called on the inode fork data,
which means after iformat_local on the read side, and prior to
ifork_flush on the write side. This makes the fork verifier more
consistent with the way buffer verifiers work -- i.e. they will operate
on the memory buffer that the code will be reading and writing directly.

Furthermore, revise the verifier function to return -EFSCORRUPTED so
that we don't flood the logs with corruption messages and assert
notices. This has been a particular problem with xfs/348, which
triggers the XFS_WANT_CORRUPTED_RETURN assertions, which halts the
kernel when CONFIG_XFS_DEBUG=y. Disk corruption isn't supposed to do
that, at least not in a verifier.

Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/xfs/libxfs/xfs_dir2_priv.h | 3 -
fs/xfs/libxfs/xfs_dir2_sf.c | 63 ++++++++++++++++++++++++++---------------
fs/xfs/libxfs/xfs_inode_fork.c | 35 ++++++++--------------
fs/xfs/libxfs/xfs_inode_fork.h | 2 -
fs/xfs/xfs_inode.c | 19 ++++++------
5 files changed, 66 insertions(+), 56 deletions(-)

--- a/fs/xfs/libxfs/xfs_dir2_priv.h
+++ b/fs/xfs/libxfs/xfs_dir2_priv.h
@@ -126,8 +126,7 @@ extern int xfs_dir2_sf_create(struct xfs
extern int xfs_dir2_sf_lookup(struct xfs_da_args *args);
extern int xfs_dir2_sf_removename(struct xfs_da_args *args);
extern int xfs_dir2_sf_replace(struct xfs_da_args *args);
-extern int xfs_dir2_sf_verify(struct xfs_mount *mp, struct xfs_dir2_sf_hdr *sfp,
- int size);
+extern int xfs_dir2_sf_verify(struct xfs_inode *ip);

/* xfs_dir2_readdir.c */
extern int xfs_readdir(struct xfs_inode *dp, struct dir_context *ctx,
--- a/fs/xfs/libxfs/xfs_dir2_sf.c
+++ b/fs/xfs/libxfs/xfs_dir2_sf.c
@@ -632,36 +632,49 @@ xfs_dir2_sf_check(
/* Verify the consistency of an inline directory. */
int
xfs_dir2_sf_verify(
- struct xfs_mount *mp,
- struct xfs_dir2_sf_hdr *sfp,
- int size)
+ struct xfs_inode *ip)
{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_dir2_sf_hdr *sfp;
struct xfs_dir2_sf_entry *sfep;
struct xfs_dir2_sf_entry *next_sfep;
char *endp;
const struct xfs_dir_ops *dops;
+ struct xfs_ifork *ifp;
xfs_ino_t ino;
int i;
int i8count;
int offset;
+ int size;
+ int error;
__uint8_t filetype;

+ ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_LOCAL);
+ /*
+ * xfs_iread calls us before xfs_setup_inode sets up ip->d_ops,
+ * so we can only trust the mountpoint to have the right pointer.
+ */
dops = xfs_dir_get_ops(mp, NULL);

+ ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+ sfp = (struct xfs_dir2_sf_hdr *)ifp->if_u1.if_data;
+ size = ifp->if_bytes;
+
/*
* Give up if the directory is way too short.
*/
- XFS_WANT_CORRUPTED_RETURN(mp, size >
- offsetof(struct xfs_dir2_sf_hdr, parent));
- XFS_WANT_CORRUPTED_RETURN(mp, size >=
- xfs_dir2_sf_hdr_size(sfp->i8count));
+ if (size <= offsetof(struct xfs_dir2_sf_hdr, parent) ||
+ size < xfs_dir2_sf_hdr_size(sfp->i8count))
+ return -EFSCORRUPTED;

endp = (char *)sfp + size;

/* Check .. entry */
ino = dops->sf_get_parent_ino(sfp);
i8count = ino > XFS_DIR2_MAX_SHORT_INUM;
- XFS_WANT_CORRUPTED_RETURN(mp, !xfs_dir_ino_validate(mp, ino));
+ error = xfs_dir_ino_validate(mp, ino);
+ if (error)
+ return error;
offset = dops->data_first_offset;

/* Check all reported entries */
@@ -672,12 +685,12 @@ xfs_dir2_sf_verify(
* Check the fixed-offset parts of the structure are
* within the data buffer.
*/
- XFS_WANT_CORRUPTED_RETURN(mp,
- ((char *)sfep + sizeof(*sfep)) < endp);
+ if (((char *)sfep + sizeof(*sfep)) >= endp)
+ return -EFSCORRUPTED;

/* Don't allow names with known bad length. */
- XFS_WANT_CORRUPTED_RETURN(mp, sfep->namelen > 0);
- XFS_WANT_CORRUPTED_RETURN(mp, sfep->namelen < MAXNAMELEN);
+ if (sfep->namelen == 0)
+ return -EFSCORRUPTED;

/*
* Check that the variable-length part of the structure is
@@ -685,33 +698,39 @@ xfs_dir2_sf_verify(
* name component, so nextentry is an acceptable test.
*/
next_sfep = dops->sf_nextentry(sfp, sfep);
- XFS_WANT_CORRUPTED_RETURN(mp, endp >= (char *)next_sfep);
+ if (endp < (char *)next_sfep)
+ return -EFSCORRUPTED;

/* Check that the offsets always increase. */
- XFS_WANT_CORRUPTED_RETURN(mp,
- xfs_dir2_sf_get_offset(sfep) >= offset);
+ if (xfs_dir2_sf_get_offset(sfep) < offset)
+ return -EFSCORRUPTED;

/* Check the inode number. */
ino = dops->sf_get_ino(sfp, sfep);
i8count += ino > XFS_DIR2_MAX_SHORT_INUM;
- XFS_WANT_CORRUPTED_RETURN(mp, !xfs_dir_ino_validate(mp, ino));
+ error = xfs_dir_ino_validate(mp, ino);
+ if (error)
+ return error;

/* Check the file type. */
filetype = dops->sf_get_ftype(sfep);
- XFS_WANT_CORRUPTED_RETURN(mp, filetype < XFS_DIR3_FT_MAX);
+ if (filetype >= XFS_DIR3_FT_MAX)
+ return -EFSCORRUPTED;

offset = xfs_dir2_sf_get_offset(sfep) +
dops->data_entsize(sfep->namelen);

sfep = next_sfep;
}
- XFS_WANT_CORRUPTED_RETURN(mp, i8count == sfp->i8count);
- XFS_WANT_CORRUPTED_RETURN(mp, (void *)sfep == (void *)endp);
+ if (i8count != sfp->i8count)
+ return -EFSCORRUPTED;
+ if ((void *)sfep != (void *)endp)
+ return -EFSCORRUPTED;

/* Make sure this whole thing ought to be in local format. */
- XFS_WANT_CORRUPTED_RETURN(mp, offset +
- (sfp->count + 2) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
- (uint)sizeof(xfs_dir2_block_tail_t) <= mp->m_dir_geo->blksize);
+ if (offset + (sfp->count + 2) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
+ (uint)sizeof(xfs_dir2_block_tail_t) > mp->m_dir_geo->blksize)
+ return -EFSCORRUPTED;

return 0;
}
--- a/fs/xfs/libxfs/xfs_inode_fork.c
+++ b/fs/xfs/libxfs/xfs_inode_fork.c
@@ -212,6 +212,16 @@ xfs_iformat_fork(
if (error)
return error;

+ /* Check inline dir contents. */
+ if (S_ISDIR(VFS_I(ip)->i_mode) &&
+ dip->di_format == XFS_DINODE_FMT_LOCAL) {
+ error = xfs_dir2_sf_verify(ip);
+ if (error) {
+ xfs_idestroy_fork(ip, XFS_DATA_FORK);
+ return error;
+ }
+ }
+
if (xfs_is_reflink_inode(ip)) {
ASSERT(ip->i_cowfp == NULL);
xfs_ifork_init_cow(ip);
@@ -322,8 +332,6 @@ xfs_iformat_local(
int whichfork,
int size)
{
- int error;
-
/*
* If the size is unreasonable, then something
* is wrong and we just bail out rather than crash in
@@ -339,14 +347,6 @@ xfs_iformat_local(
return -EFSCORRUPTED;
}

- if (S_ISDIR(VFS_I(ip)->i_mode) && whichfork == XFS_DATA_FORK) {
- error = xfs_dir2_sf_verify(ip->i_mount,
- (struct xfs_dir2_sf_hdr *)XFS_DFORK_DPTR(dip),
- size);
- if (error)
- return error;
- }
-
xfs_init_local_fork(ip, whichfork, XFS_DFORK_PTR(dip, whichfork), size);
return 0;
}
@@ -867,7 +867,7 @@ xfs_iextents_copy(
* In these cases, the format always takes precedence, because the
* format indicates the current state of the fork.
*/
-int
+void
xfs_iflush_fork(
xfs_inode_t *ip,
xfs_dinode_t *dip,
@@ -877,7 +877,6 @@ xfs_iflush_fork(
char *cp;
xfs_ifork_t *ifp;
xfs_mount_t *mp;
- int error;
static const short brootflag[2] =
{ XFS_ILOG_DBROOT, XFS_ILOG_ABROOT };
static const short dataflag[2] =
@@ -886,7 +885,7 @@ xfs_iflush_fork(
{ XFS_ILOG_DEXT, XFS_ILOG_AEXT };

if (!iip)
- return 0;
+ return;
ifp = XFS_IFORK_PTR(ip, whichfork);
/*
* This can happen if we gave up in iformat in an error path,
@@ -894,19 +893,12 @@ xfs_iflush_fork(
*/
if (!ifp) {
ASSERT(whichfork == XFS_ATTR_FORK);
- return 0;
+ return;
}
cp = XFS_DFORK_PTR(dip, whichfork);
mp = ip->i_mount;
switch (XFS_IFORK_FORMAT(ip, whichfork)) {
case XFS_DINODE_FMT_LOCAL:
- if (S_ISDIR(VFS_I(ip)->i_mode) && whichfork == XFS_DATA_FORK) {
- error = xfs_dir2_sf_verify(mp,
- (struct xfs_dir2_sf_hdr *)ifp->if_u1.if_data,
- ifp->if_bytes);
- if (error)
- return error;
- }
if ((iip->ili_fields & dataflag[whichfork]) &&
(ifp->if_bytes > 0)) {
ASSERT(ifp->if_u1.if_data != NULL);
@@ -959,7 +951,6 @@ xfs_iflush_fork(
ASSERT(0);
break;
}
- return 0;
}

/*
--- a/fs/xfs/libxfs/xfs_inode_fork.h
+++ b/fs/xfs/libxfs/xfs_inode_fork.h
@@ -140,7 +140,7 @@ typedef struct xfs_ifork {
struct xfs_ifork *xfs_iext_state_to_fork(struct xfs_inode *ip, int state);

int xfs_iformat_fork(struct xfs_inode *, struct xfs_dinode *);
-int xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
+void xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
struct xfs_inode_log_item *, int);
void xfs_idestroy_fork(struct xfs_inode *, int);
void xfs_idata_realloc(struct xfs_inode *, int, int);
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -50,6 +50,7 @@
#include "xfs_log.h"
#include "xfs_bmap_btree.h"
#include "xfs_reflink.h"
+#include "xfs_dir2_priv.h"

kmem_zone_t *xfs_inode_zone;

@@ -3491,7 +3492,6 @@ xfs_iflush_int(
struct xfs_inode_log_item *iip = ip->i_itemp;
struct xfs_dinode *dip;
struct xfs_mount *mp = ip->i_mount;
- int error;

ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
ASSERT(xfs_isiflocked(ip));
@@ -3563,6 +3563,12 @@ xfs_iflush_int(
if (ip->i_d.di_version < 3)
ip->i_d.di_flushiter++;

+ /* Check the inline directory data. */
+ if (S_ISDIR(VFS_I(ip)->i_mode) &&
+ ip->i_d.di_format == XFS_DINODE_FMT_LOCAL &&
+ xfs_dir2_sf_verify(ip))
+ goto corrupt_out;
+
/*
* Copy the dirty parts of the inode into the on-disk inode. We always
* copy out the core of the inode, because if the inode is dirty at all
@@ -3574,14 +3580,9 @@ xfs_iflush_int(
if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
ip->i_d.di_flushiter = 0;

- error = xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
- if (error)
- return error;
- if (XFS_IFORK_Q(ip)) {
- error = xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
- if (error)
- return error;
- }
+ xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
+ if (XFS_IFORK_Q(ip))
+ xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
xfs_inobp_check(mp, bp);

/*