[PATCH 6.6 09/21] xfs: enforce one namespace per attribute

Catherine Hoang
2024-10-16T00:11:51Z

From: "Darrick J. Wong" <djwong@kernel.org>

commit ea0b3e814741fb64e7785b564ea619578058e0b0 upstream.

[backport: fix conflicts due to various xattr refactoring]

Create a standardized helper function to enforce one namespace bit per
extended attribute, and refactor all the open-coded hweight logic. This
function is not a static inline to avoid porting hassles in userspace.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Catherine Hoang <catherine.hoang@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/libxfs/xfs_attr.c | 11 +++++++++++
fs/xfs/libxfs/xfs_attr.h | 4 +++-
fs/xfs/libxfs/xfs_attr_leaf.c | 6 +++++-
fs/xfs/scrub/attr.c | 12 +++++-------
fs/xfs/xfs_attr_item.c | 10 ++++++++--
fs/xfs/xfs_attr_list.c | 11 +++++++----
6 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index 32d350e97e0f..33edf047e0ad 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -1565,12 +1565,23 @@ xfs_attr_node_get(
return error;
}

+/* Enforce that there is at most one namespace bit per attr. */
+inline bool xfs_attr_check_namespace(unsigned int attr_flags)
+{
+ return hweight32(attr_flags & XFS_ATTR_NSP_ONDISK_MASK) < 2;
+}
+
/* Returns true if the attribute entry name is valid. */
bool
xfs_attr_namecheck(
+ unsigned int attr_flags,
const void *name,
size_t length)
{
+ /* Only one namespace bit allowed. */
+ if (!xfs_attr_check_namespace(attr_flags))
+ return false;
+
/*
* MAXNAMELEN includes the trailing null, but (name/length) leave it
* out, so use >= for the length check.
diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
index 81be9b3e4004..c877f05e3cd1 100644
--- a/fs/xfs/libxfs/xfs_attr.h
+++ b/fs/xfs/libxfs/xfs_attr.h
@@ -547,7 +547,9 @@ int xfs_attr_get(struct xfs_da_args *args);
int xfs_attr_set(struct xfs_da_args *args);
int xfs_attr_set_iter(struct xfs_attr_intent *attr);
int xfs_attr_remove_iter(struct xfs_attr_intent *attr);
-bool xfs_attr_namecheck(const void *name, size_t length);
+bool xfs_attr_check_namespace(unsigned int attr_flags);
+bool xfs_attr_namecheck(unsigned int attr_flags, const void *name,
+ size_t length);
int xfs_attr_calc_size(struct xfs_da_args *args, int *local);
void xfs_init_attr_trans(struct xfs_da_args *args, struct xfs_trans_res *tres,
unsigned int *total);
diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
index 2580ae47209a..51ff44068675 100644
--- a/fs/xfs/libxfs/xfs_attr_leaf.c
+++ b/fs/xfs/libxfs/xfs_attr_leaf.c
@@ -984,6 +984,10 @@ xfs_attr_shortform_to_leaf(
nargs.hashval = xfs_da_hashname(sfe->nameval,
sfe->namelen);
nargs.attr_filter = sfe->flags & XFS_ATTR_NSP_ONDISK_MASK;
+ if (!xfs_attr_check_namespace(sfe->flags)) {
+ error = -EFSCORRUPTED;
+ goto out;
+ }
error = xfs_attr3_leaf_lookup_int(bp, &nargs); /* set a->index */
ASSERT(error == -ENOATTR);
error = xfs_attr3_leaf_add(bp, &nargs);
@@ -1105,7 +1109,7 @@ xfs_attr_shortform_verify(
* one namespace flag per xattr, so we can just count the
* bits (i.e. hweight) here.
*/
- if (hweight8(sfep->flags & XFS_ATTR_NSP_ONDISK_MASK) > 1)
+ if (!xfs_attr_check_namespace(sfep->flags))
return __this_address;

sfep = next_sfep;
diff --git a/fs/xfs/scrub/attr.c b/fs/xfs/scrub/attr.c
index 419968d5f5cb..7cb0af5e34b1 100644
--- a/fs/xfs/scrub/attr.c
+++ b/fs/xfs/scrub/attr.c
@@ -193,14 +193,8 @@ xchk_xattr_listent(
return;
}

- /* Only one namespace bit allowed. */
- if (hweight32(flags & XFS_ATTR_NSP_ONDISK_MASK) > 1) {
- xchk_fblock_set_corrupt(sx->sc, XFS_ATTR_FORK, args.blkno);
- goto fail_xref;
- }
-
/* Does this name make sense? */
- if (!xfs_attr_namecheck(name, namelen)) {
+ if (!xfs_attr_namecheck(flags, name, namelen)) {
xchk_fblock_set_corrupt(sx->sc, XFS_ATTR_FORK, args.blkno);
goto fail_xref;
}
@@ -501,6 +495,10 @@ xchk_xattr_rec(
xchk_da_set_corrupt(ds, level);
return 0;
}
+ if (!xfs_attr_check_namespace(ent->flags)) {
+ xchk_da_set_corrupt(ds, level);
+ return 0;
+ }

if (ent->flags & XFS_ATTR_LOCAL) {
lentry = (struct xfs_attr_leaf_name_local *)
diff --git a/fs/xfs/xfs_attr_item.c b/fs/xfs/xfs_attr_item.c
index 141631b0d64c..df86c9c09720 100644
--- a/fs/xfs/xfs_attr_item.c
+++ b/fs/xfs/xfs_attr_item.c
@@ -522,6 +522,10 @@ xfs_attri_validate(
if (attrp->alfi_attr_filter & ~XFS_ATTRI_FILTER_MASK)
return false;

+ if (!xfs_attr_check_namespace(attrp->alfi_attr_filter &
+ XFS_ATTR_NSP_ONDISK_MASK))
+ return false;
+
/* alfi_op_flags should be either a set or remove */
switch (op) {
case XFS_ATTRI_OP_FLAGS_SET:
@@ -572,7 +576,8 @@ xfs_attri_item_recover(
*/
attrp = &attrip->attri_format;
if (!xfs_attri_validate(mp, attrp) ||
- !xfs_attr_namecheck(nv->name.i_addr, nv->name.i_len))
+ !xfs_attr_namecheck(attrp->alfi_attr_filter, nv->name.i_addr,
+ nv->name.i_len))
return -EFSCORRUPTED;

error = xlog_recover_iget(mp, attrp->alfi_ino, &ip);
@@ -772,7 +777,8 @@ xlog_recover_attri_commit_pass2(
}

attr_name = item->ri_buf[i].i_addr;
- if (!xfs_attr_namecheck(attr_name, attri_formatp->alfi_name_len)) {
+ if (!xfs_attr_namecheck(attri_formatp->alfi_attr_filter, attr_name,
+ attri_formatp->alfi_name_len)) {
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
attri_formatp, len);
return -EFSCORRUPTED;
diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
index 99bbbe1a0e44..9ee1d7d2ba76 100644
--- a/fs/xfs/xfs_attr_list.c
+++ b/fs/xfs/xfs_attr_list.c
@@ -82,7 +82,8 @@ xfs_attr_shortform_list(
(dp->i_af.if_bytes + sf->hdr.count * 16) < context->bufsize)) {
for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
if (XFS_IS_CORRUPT(context->dp->i_mount,
- !xfs_attr_namecheck(sfe->nameval,
+ !xfs_attr_namecheck(sfe->flags,
+ sfe->nameval,
sfe->namelen)))
return -EFSCORRUPTED;
context->put_listent(context,
@@ -120,7 +121,8 @@ xfs_attr_shortform_list(
for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
if (unlikely(
((char *)sfe < (char *)sf) ||
- ((char *)sfe >= ((char *)sf + dp->i_af.if_bytes)))) {
+ ((char *)sfe >= ((char *)sf + dp->i_af.if_bytes)) ||
+ !xfs_attr_check_namespace(sfe->flags))) {
XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
XFS_ERRLEVEL_LOW,
context->dp->i_mount, sfe,
@@ -174,7 +176,7 @@ xfs_attr_shortform_list(
cursor->offset = 0;
}
if (XFS_IS_CORRUPT(context->dp->i_mount,
- !xfs_attr_namecheck(sbp->name,
+ !xfs_attr_namecheck(sbp->flags, sbp->name,
sbp->namelen))) {
error = -EFSCORRUPTED;
goto out;
@@ -465,7 +467,8 @@ xfs_attr3_leaf_list_int(
}

if (XFS_IS_CORRUPT(context->dp->i_mount,
- !xfs_attr_namecheck(name, namelen)))
+ !xfs_attr_namecheck(entry->flags, name,
+ namelen)))
return -EFSCORRUPTED;
context->put_listent(context, entry->flags,
name, namelen, valuelen);
--
2.39.3