From b3bf607d58520ea8c0666aeb4be60dbb724cd3a2 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 2 Feb 2017 15:13:59 -0800 Subject: [PATCH] xfs: check for obviously bad level values in the bmbt root We can't handle a bmbt that's taller than BTREE_MAXLEVELS, and there's no such thing as a zero-level bmbt (for that we have extents format), so if we see this, send back an error code. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/libxfs/xfs_inode_fork.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c index 421341f..25c1e07 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.c +++ b/fs/xfs/libxfs/xfs_inode_fork.c @@ -26,6 +26,7 @@ #include "xfs_inode.h" #include "xfs_trans.h" #include "xfs_inode_item.h" +#include "xfs_btree.h" #include "xfs_bmap_btree.h" #include "xfs_bmap.h" #include "xfs_error.h" @@ -429,11 +430,13 @@ xfs_iformat_btree( /* REFERENCED */ int nrecs; int size; + int level; ifp = XFS_IFORK_PTR(ip, whichfork); dfp = (xfs_bmdr_block_t *)XFS_DFORK_PTR(dip, whichfork); size = XFS_BMAP_BROOT_SPACE(mp, dfp); nrecs = be16_to_cpu(dfp->bb_numrecs); + level = be16_to_cpu(dfp->bb_level); /* * blow out if -- fork has less extents than can fit in @@ -446,7 +449,8 @@ xfs_iformat_btree( XFS_IFORK_MAXEXT(ip, whichfork) || XFS_BMDR_SPACE_CALC(nrecs) > XFS_DFORK_SIZE(dip, mp, whichfork) || - XFS_IFORK_NEXTENTS(ip, whichfork) > ip->i_d.di_nblocks)) { + XFS_IFORK_NEXTENTS(ip, whichfork) > ip->i_d.di_nblocks) || + level == 0 || level > XFS_BTREE_MAXLEVELS) { xfs_warn(mp, "corrupt inode %Lu (btree).", (unsigned long long) ip->i_ino); XFS_CORRUPTION_ERROR("xfs_iformat_btree", XFS_ERRLEVEL_LOW, -- 2.7.4