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authorDarrick J. Wong <darrick.wong@oracle.com>2018-06-04 13:58:34 -0700
committerDarrick J. Wong <darrick.wong@oracle.com>2018-06-04 18:25:05 -0700
commite63a1008ee08334ea6a9c9edb59b1d2763f5b231 (patch)
treee831aa46e58916f523a26409f42a1cc8feaf8f23
parent4cbae4b816fd61e63abbe8330741e257fa95d4c5 (diff)
downloadlinux-e63a1008ee08334ea6a9c9edb59b1d2763f5b231.tar.bz2
xfs: strengthen btree pointer checks before use
Instead of ASSERTing on null btree pointers in xfs_btree_ptr_to_daddr, use the new block number verifiers to ensure that the btree pointer doesn't point to any sensitive areas (AG headers, past-EOFS) and return -EFSCORRUPTED if this is the case. Remove the ASSERT because on-disk corruptions shouldn't trigger ASSERTs. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
-rw-r--r--fs/xfs/libxfs/xfs_btree.c50
1 files changed, 35 insertions, 15 deletions
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index f30d74d807e9..3fcddfeaa662 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -992,22 +992,30 @@ xfs_btree_readahead(
return xfs_btree_readahead_sblock(cur, lr, block);
}
-STATIC xfs_daddr_t
+STATIC int
xfs_btree_ptr_to_daddr(
struct xfs_btree_cur *cur,
- union xfs_btree_ptr *ptr)
+ union xfs_btree_ptr *ptr,
+ xfs_daddr_t *daddr)
{
- if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
- ASSERT(ptr->l != cpu_to_be64(NULLFSBLOCK));
+ xfs_fsblock_t fsbno;
+ xfs_agblock_t agbno;
+ int error;
- return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
- } else {
- ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
- ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK));
+ error = xfs_btree_check_ptr(cur, ptr, 0, 1);
+ if (error)
+ return error;
- return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
- be32_to_cpu(ptr->s));
+ if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
+ fsbno = be64_to_cpu(ptr->l);
+ *daddr = XFS_FSB_TO_DADDR(cur->bc_mp, fsbno);
+ } else {
+ agbno = be32_to_cpu(ptr->s);
+ *daddr = XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
+ agbno);
}
+
+ return 0;
}
/*
@@ -1022,8 +1030,11 @@ xfs_btree_readahead_ptr(
union xfs_btree_ptr *ptr,
xfs_extlen_t count)
{
- xfs_buf_readahead(cur->bc_mp->m_ddev_targp,
- xfs_btree_ptr_to_daddr(cur, ptr),
+ xfs_daddr_t daddr;
+
+ if (xfs_btree_ptr_to_daddr(cur, ptr, &daddr))
+ return;
+ xfs_buf_readahead(cur->bc_mp->m_ddev_targp, daddr,
cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops);
}
@@ -1286,11 +1297,14 @@ xfs_btree_get_buf_block(
{
struct xfs_mount *mp = cur->bc_mp;
xfs_daddr_t d;
+ int error;
/* need to sort out how callers deal with failures first */
ASSERT(!(flags & XBF_TRYLOCK));
- d = xfs_btree_ptr_to_daddr(cur, ptr);
+ error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
+ if (error)
+ return error;
*bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
mp->m_bsize, flags);
@@ -1321,7 +1335,9 @@ xfs_btree_read_buf_block(
/* need to sort out how callers deal with failures first */
ASSERT(!(flags & XBF_TRYLOCK));
- d = xfs_btree_ptr_to_daddr(cur, ptr);
+ error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
+ if (error)
+ return error;
error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
mp->m_bsize, flags, bpp,
cur->bc_ops->buf_ops);
@@ -1768,6 +1784,7 @@ xfs_btree_lookup_get_block(
struct xfs_btree_block **blkp) /* return btree block */
{
struct xfs_buf *bp; /* buffer pointer for btree block */
+ xfs_daddr_t daddr;
int error = 0;
/* special case the root block if in an inode */
@@ -1784,7 +1801,10 @@ xfs_btree_lookup_get_block(
* Otherwise throw it away and get a new one.
*/
bp = cur->bc_bufs[level];
- if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
+ error = xfs_btree_ptr_to_daddr(cur, pp, &daddr);
+ if (error)
+ return error;
+ if (bp && XFS_BUF_ADDR(bp) == daddr) {
*blkp = XFS_BUF_TO_BLOCK(bp);
return 0;
}