Merge branch 'guilt/xfs-5.19-fuzz-fixes' into xfs-5.19-for-next

3 files changed, 191 insertions, 54 deletions

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index a8c79e760d8a..2aa300f7461f 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -51,6 +51,52 @@ xfs_btree_magic(
 	return magic;
 }
 
+static xfs_failaddr_t
+xfs_btree_check_lblock_siblings(
+	struct xfs_mount	*mp,
+	struct xfs_btree_cur	*cur,
+	int			level,
+	xfs_fsblock_t		fsb,
+	xfs_fsblock_t		sibling)
+{
+	if (sibling == NULLFSBLOCK)
+		return NULL;
+	if (sibling == fsb)
+		return __this_address;
+	if (level >= 0) {
+		if (!xfs_btree_check_lptr(cur, sibling, level + 1))
+			return __this_address;
+	} else {
+		if (!xfs_verify_fsbno(mp, sibling))
+			return __this_address;
+	}
+
+	return NULL;
+}
+
+static xfs_failaddr_t
+xfs_btree_check_sblock_siblings(
+	struct xfs_mount	*mp,
+	struct xfs_btree_cur	*cur,
+	int			level,
+	xfs_agnumber_t		agno,
+	xfs_agblock_t		agbno,
+	xfs_agblock_t		sibling)
+{
+	if (sibling == NULLAGBLOCK)
+		return NULL;
+	if (sibling == agbno)
+		return __this_address;
+	if (level >= 0) {
+		if (!xfs_btree_check_sptr(cur, sibling, level + 1))
+			return __this_address;
+	} else {
+		if (!xfs_verify_agbno(mp, agno, sibling))
+			return __this_address;
+	}
+	return NULL;
+}
+
 /*
  * Check a long btree block header.  Return the address of the failing check,
  * or NULL if everything is ok.
@@ -65,6 +111,8 @@ __xfs_btree_check_lblock(
 	struct xfs_mount	*mp = cur->bc_mp;
 	xfs_btnum_t		btnum = cur->bc_btnum;
 	int			crc = xfs_has_crc(mp);
+	xfs_failaddr_t		fa;
+	xfs_fsblock_t		fsb = NULLFSBLOCK;
 
 	if (crc) {
 		if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
@@ -83,16 +131,16 @@ __xfs_btree_check_lblock(
 	if (be16_to_cpu(block->bb_numrecs) >
 	    cur->bc_ops->get_maxrecs(cur, level))
 		return __this_address;
-	if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
-	    !xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_leftsib),
-			level + 1))
-		return __this_address;
-	if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
-	    !xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_rightsib),
-			level + 1))
-		return __this_address;
 
-	return NULL;
+	if (bp)
+		fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
+
+	fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb,
+			be64_to_cpu(block->bb_u.l.bb_leftsib));
+	if (!fa)
+		fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb,
+				be64_to_cpu(block->bb_u.l.bb_rightsib));
+	return fa;
 }
 
 /* Check a long btree block header. */
@@ -130,6 +178,9 @@ __xfs_btree_check_sblock(
 	struct xfs_mount	*mp = cur->bc_mp;
 	xfs_btnum_t		btnum = cur->bc_btnum;
 	int			crc = xfs_has_crc(mp);
+	xfs_failaddr_t		fa;
+	xfs_agblock_t		agbno = NULLAGBLOCK;
+	xfs_agnumber_t		agno = NULLAGNUMBER;
 
 	if (crc) {
 		if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
@@ -146,16 +197,18 @@ __xfs_btree_check_sblock(
 	if (be16_to_cpu(block->bb_numrecs) >
 	    cur->bc_ops->get_maxrecs(cur, level))
 		return __this_address;
-	if (block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK) &&
-	    !xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_leftsib),
-			level + 1))
-		return __this_address;
-	if (block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK) &&
-	    !xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_rightsib),
-			level + 1))
-		return __this_address;
 
-	return NULL;
+	if (bp) {
+		agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
+		agno = xfs_daddr_to_agno(mp, xfs_buf_daddr(bp));
+	}
+
+	fa = xfs_btree_check_sblock_siblings(mp, cur, level, agno, agbno,
+			be32_to_cpu(block->bb_u.s.bb_leftsib));
+	if (!fa)
+		fa = xfs_btree_check_sblock_siblings(mp, cur, level, agno,
+				 agbno, be32_to_cpu(block->bb_u.s.bb_rightsib));
+	return fa;
 }
 
 /* Check a short btree block header. */
@@ -4271,6 +4324,21 @@ xfs_btree_visit_block(
 	if (xfs_btree_ptr_is_null(cur, &rptr))
 		return -ENOENT;
 
+	/*
+	 * We only visit blocks once in this walk, so we have to avoid the
+	 * internal xfs_btree_lookup_get_block() optimisation where it will
+	 * return the same block without checking if the right sibling points
+	 * back to us and creates a cyclic reference in the btree.
+	 */
+	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
+		if (be64_to_cpu(rptr.l) == XFS_DADDR_TO_FSB(cur->bc_mp,
+							xfs_buf_daddr(bp)))
+			return -EFSCORRUPTED;
+	} else {
+		if (be32_to_cpu(rptr.s) == xfs_daddr_to_agbno(cur->bc_mp,
+							xfs_buf_daddr(bp)))
+			return -EFSCORRUPTED;
+	}
 	return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
 }
 
@@ -4445,20 +4513,21 @@ xfs_btree_lblock_verify(
 {
 	struct xfs_mount	*mp = bp->b_mount;
 	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
+	xfs_fsblock_t		fsb;
+	xfs_failaddr_t		fa;
 
 	/* numrecs verification */
 	if (be16_to_cpu(block->bb_numrecs) > max_recs)
 		return __this_address;
 
 	/* sibling pointer verification */
-	if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
-	    !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_leftsib)))
-		return __this_address;
-	if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
-	    !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_rightsib)))
-		return __this_address;
-
-	return NULL;
+	fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
+	fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb,
+			be64_to_cpu(block->bb_u.l.bb_leftsib));
+	if (!fa)
+		fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb,
+				be64_to_cpu(block->bb_u.l.bb_rightsib));
+	return fa;
 }
 
 /**
@@ -4499,7 +4568,9 @@ xfs_btree_sblock_verify(
 {
 	struct xfs_mount	*mp = bp->b_mount;
 	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
-	xfs_agblock_t		agno;
+	xfs_agnumber_t		agno;
+	xfs_agblock_t		agbno;
+	xfs_failaddr_t		fa;
 
 	/* numrecs verification */
 	if (be16_to_cpu(block->bb_numrecs) > max_recs)
@@ -4507,14 +4578,13 @@ xfs_btree_sblock_verify(
 
 	/* sibling pointer verification */
 	agno = xfs_daddr_to_agno(mp, xfs_buf_daddr(bp));
-	if (block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK) &&
-	    !xfs_verify_agbno(mp, agno, be32_to_cpu(block->bb_u.s.bb_leftsib)))
-		return __this_address;
-	if (block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK) &&
-	    !xfs_verify_agbno(mp, agno, be32_to_cpu(block->bb_u.s.bb_rightsib)))
-		return __this_address;
-
-	return NULL;
+	agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
+	fa = xfs_btree_check_sblock_siblings(mp, NULL, -1, agno, agbno,
+			be32_to_cpu(block->bb_u.s.bb_leftsib));
+	if (!fa)
+		fa = xfs_btree_check_sblock_siblings(mp, NULL, -1, agno, agbno,
+				be32_to_cpu(block->bb_u.s.bb_rightsib));
+	return fa;
 }
 
 /*
diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
index 74b82ec80f8e..3b1b63f9d886 100644
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -357,21 +357,38 @@ xfs_dinode_verify_fork(
 {
 	xfs_extnum_t		di_nextents;
 	xfs_extnum_t		max_extents;
+	mode_t			mode = be16_to_cpu(dip->di_mode);
+	uint32_t		fork_size = XFS_DFORK_SIZE(dip, mp, whichfork);
+	uint32_t		fork_format = XFS_DFORK_FORMAT(dip, whichfork);
 
 	di_nextents = xfs_dfork_nextents(dip, whichfork);
 
-	switch (XFS_DFORK_FORMAT(dip, whichfork)) {
+	/*
+	 * For fork types that can contain local data, check that the fork
+	 * format matches the size of local data contained within the fork.
+	 *
+	 * For all types, check that when the size says the should be in extent
+	 * or btree format, the inode isn't claiming it is in local format.
+	 */
+	if (whichfork == XFS_DATA_FORK) {
+		if (S_ISDIR(mode) || S_ISLNK(mode)) {
+			if (be64_to_cpu(dip->di_size) <= fork_size &&
+			    fork_format != XFS_DINODE_FMT_LOCAL)
+				return __this_address;
+		}
+
+		if (be64_to_cpu(dip->di_size) > fork_size &&
+		    fork_format == XFS_DINODE_FMT_LOCAL)
+			return __this_address;
+	}
+
+	switch (fork_format) {
 	case XFS_DINODE_FMT_LOCAL:
 		/*
-		 * no local regular files yet
+		 * No local regular files yet.
 		 */
-		if (whichfork == XFS_DATA_FORK) {
-			if (S_ISREG(be16_to_cpu(dip->di_mode)))
-				return __this_address;
-			if (be64_to_cpu(dip->di_size) >
-					XFS_DFORK_SIZE(dip, mp, whichfork))
-				return __this_address;
-		}
+		if (S_ISREG(mode) && whichfork == XFS_DATA_FORK)
+			return __this_address;
 		if (di_nextents)
 			return __this_address;
 		break;
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index cf9e5b9374c1..a20cade590e9 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -31,15 +31,66 @@
  */
 
 /*
+ * Check that all the V4 feature bits that the V5 filesystem format requires are
+ * correctly set.
+ */
+static bool
+xfs_sb_validate_v5_features(
+	struct xfs_sb	*sbp)
+{
+	/* We must not have any unknown V4 feature bits set */
+	if (sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS)
+		return false;
+
+	/*
+	 * The CRC bit is considered an invalid V4 flag, so we have to add it
+	 * manually to the OKBITS mask.
+	 */
+	if (sbp->sb_features2 & ~(XFS_SB_VERSION2_OKBITS |
+				  XFS_SB_VERSION2_CRCBIT))
+		return false;
+
+	/* Now check all the required V4 feature flags are set. */
+
+#define V5_VERS_FLAGS	(XFS_SB_VERSION_NLINKBIT	| \
+			XFS_SB_VERSION_ALIGNBIT		| \
+			XFS_SB_VERSION_LOGV2BIT		| \
+			XFS_SB_VERSION_EXTFLGBIT	| \
+			XFS_SB_VERSION_DIRV2BIT		| \
+			XFS_SB_VERSION_MOREBITSBIT)
+
+#define V5_FEAT_FLAGS	(XFS_SB_VERSION2_LAZYSBCOUNTBIT	| \
+			XFS_SB_VERSION2_ATTR2BIT	| \
+			XFS_SB_VERSION2_PROJID32BIT	| \
+			XFS_SB_VERSION2_CRCBIT)
+
+	if ((sbp->sb_versionnum & V5_VERS_FLAGS) != V5_VERS_FLAGS)
+		return false;
+	if ((sbp->sb_features2 & V5_FEAT_FLAGS) != V5_FEAT_FLAGS)
+		return false;
+	return true;
+}
+
+/*
  * We support all XFS versions newer than a v4 superblock with V2 directories.
  */
 bool
 xfs_sb_good_version(
 	struct xfs_sb	*sbp)
 {
-	/* all v5 filesystems are supported */
+	/*
+	 * All v5 filesystems are supported, but we must check that all the
+	 * required v4 feature flags are enabled correctly as the code checks
+	 * those flags and not for v5 support.
+	 */
 	if (xfs_sb_is_v5(sbp))
-		return true;
+		return xfs_sb_validate_v5_features(sbp);
+
+	/* We must not have any unknown v4 feature bits set */
+	if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) ||
+	    ((sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) &&
+	     (sbp->sb_features2 & ~XFS_SB_VERSION2_OKBITS)))
+		return false;
 
 	/* versions prior to v4 are not supported */
 	if (XFS_SB_VERSION_NUM(sbp) < XFS_SB_VERSION_4)
@@ -51,12 +102,6 @@ xfs_sb_good_version(
 	if (!(sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT))
 		return false;
 
-	/* And must not have any unknown v4 feature bits set */
-	if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) ||
-	    ((sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) &&
-	     (sbp->sb_features2 & ~XFS_SB_VERSION2_OKBITS)))
-		return false;
-
 	/* It's a supported v4 filesystem */
 	return true;
 }
@@ -70,6 +115,8 @@ xfs_sb_version_to_features(
 	/* optional V4 features */
 	if (sbp->sb_rblocks > 0)
 		features |= XFS_FEAT_REALTIME;
+	if (sbp->sb_versionnum & XFS_SB_VERSION_NLINKBIT)
+		features |= XFS_FEAT_NLINK;
 	if (sbp->sb_versionnum & XFS_SB_VERSION_ATTRBIT)
 		features |= XFS_FEAT_ATTR;
 	if (sbp->sb_versionnum & XFS_SB_VERSION_QUOTABIT)
@@ -265,12 +312,15 @@ xfs_validate_sb_common(
 	bool			has_dalign;
 
 	if (!xfs_verify_magic(bp, dsb->sb_magicnum)) {
-		xfs_warn(mp, "bad magic number");
+		xfs_warn(mp,
+"Superblock has bad magic number 0x%x. Not an XFS filesystem?",
+			be32_to_cpu(dsb->sb_magicnum));
 		return -EWRONGFS;
 	}
 
 	if (!xfs_sb_good_version(sbp)) {
-		xfs_warn(mp, "bad version");
+		xfs_warn(mp,
+"Superblock has unknown features enabled or corrupted feature masks.");
 		return -EWRONGFS;
 	}