From c84760659dcf237902d4cc997cd5f55cb3b2807f Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Mon, 28 Oct 2019 16:12:33 -0700
Subject: [PATCH] xfs: check attribute leaf block structure
Git-commit: c84760659dcf237902d4cc997cd5f55cb3b2807f
Patch-mainline: v5.5-rc1
References: bsc#1166153
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>
Acked-by: Anthony Iliopoulos <ailiopoulos@suse.com>
---
fs/xfs/libxfs/xfs_attr_leaf.c | 67 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 65 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
index 962319e1e128..56e62b3d9bb7 100644
--- a/fs/xfs/libxfs/xfs_attr_leaf.c
+++ b/fs/xfs/libxfs/xfs_attr_leaf.c
@@ -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
--
2.16.4