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xfs: check attribute leaf block structure 

Add missing structure checks in the attribute leaf verifier.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This commit is contained in:
Darrick J. Wong 2019-10-28 16:12:33 -07:00
parent 360c09c01c
commit c84760659d
1 changed files with 65 additions and 2 deletions
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67
fs/xfs/libxfs/xfs_attr_leaf.c
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@ -232,6 +232,61 @@ xfs_attr3_leaf_hdr_to_disk(
}
}
static xfs_failaddr_t
xfs_attr3_leaf_verify_entry(
struct xfs_mount *mp,
char *buf_end,
struct xfs_attr_leafblock *leaf,
struct xfs_attr3_icleaf_hdr *leafhdr,
struct xfs_attr_leaf_entry *ent,
int idx,
__u32 *last_hashval)
{
struct xfs_attr_leaf_name_local *lentry;
struct xfs_attr_leaf_name_remote *rentry;
char *name_end;
unsigned int nameidx;
unsigned int namesize;
__u32 hashval;
/* hash order check */
hashval = be32_to_cpu(ent->hashval);
if (hashval < *last_hashval)
return __this_address;
*last_hashval = hashval;
nameidx = be16_to_cpu(ent->nameidx);
if (nameidx < leafhdr->firstused || nameidx >= mp->m_attr_geo->blksize)
return __this_address;
/*
* Check the name information. The namelen fields are u8 so we can't
* possibly exceed the maximum name length of 255 bytes.
*/
if (ent->flags & XFS_ATTR_LOCAL) {
lentry = xfs_attr3_leaf_name_local(leaf, idx);
namesize = xfs_attr_leaf_entsize_local(lentry->namelen,
be16_to_cpu(lentry->valuelen));
name_end = (char *)lentry + namesize;
if (lentry->namelen == 0)
return __this_address;
} else {
rentry = xfs_attr3_leaf_name_remote(leaf, idx);
namesize = xfs_attr_leaf_entsize_remote(rentry->namelen);
name_end = (char *)rentry + namesize;
if (rentry->namelen == 0)
return __this_address;
if (!(ent->flags & XFS_ATTR_INCOMPLETE) &&
rentry->valueblk == 0)
return __this_address;
}
if (name_end > buf_end)
return __this_address;
return NULL;
}
static xfs_failaddr_t
xfs_attr3_leaf_verify(
struct xfs_buf *bp)
@ -240,7 +295,10 @@ xfs_attr3_leaf_verify(
struct xfs_mount *mp = bp->b_mount;
struct xfs_attr_leafblock *leaf = bp->b_addr;
struct xfs_attr_leaf_entry *entries;
struct xfs_attr_leaf_entry *ent;
char *buf_end;
uint32_t end; /* must be 32bit - see below */
__u32 last_hashval = 0;
int i;
xfs_failaddr_t fa;
@ -273,8 +331,13 @@ xfs_attr3_leaf_verify(
(char *)bp->b_addr + ichdr.firstused)
return __this_address;
/* XXX: need to range check rest of attr header values */
/* XXX: hash order check? */
buf_end = (char *)bp->b_addr + mp->m_attr_geo->blksize;
for (i = 0, ent = entries; i < ichdr.count; ent++, i++) {
fa = xfs_attr3_leaf_verify_entry(mp, buf_end, leaf, &ichdr,
ent, i, &last_hashval);
if (fa)
return fa;
}
/*
* Quickly check the freemap information. Attribute data has to be