[PATCH 06/14] xfs: check that bc_nlevels never overflows
From: "Darrick J. Wong" <djwong@kernel.org>
Date: 2021-09-18 01:29:44
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
From: Darrick J. Wong <djwong@kernel.org> Warn if we ever bump nlevels higher than the allowed maximum cursor height. Signed-off-by: Darrick J. Wong <djwong@kernel.org> --- fs/xfs/libxfs/xfs_btree.c | 2 ++ fs/xfs/libxfs/xfs_btree_staging.c | 2 ++ 2 files changed, 4 insertions(+)
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index b0cce0932f02..bc4e49f0456a 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c@@ -2933,6 +2933,7 @@ xfs_btree_new_iroot( be16_add_cpu(&block->bb_level, 1); xfs_btree_set_numrecs(block, 1); cur->bc_nlevels++; + ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS); cur->bc_ptrs[level + 1] = 1; kp = xfs_btree_key_addr(cur, 1, block);
@@ -3096,6 +3097,7 @@ xfs_btree_new_root( xfs_btree_setbuf(cur, cur->bc_nlevels, nbp); cur->bc_ptrs[cur->bc_nlevels] = nptr; cur->bc_nlevels++; + ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS); *stat = 1; return 0; error0:
diff --git a/fs/xfs/libxfs/xfs_btree_staging.c b/fs/xfs/libxfs/xfs_btree_staging.c
index ac9e80152b5c..26143297bb7b 100644
--- a/fs/xfs/libxfs/xfs_btree_staging.c
+++ b/fs/xfs/libxfs/xfs_btree_staging.c@@ -703,6 +703,7 @@ xfs_btree_bload_compute_geometry( * block-based btree level. */ cur->bc_nlevels++; + ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS); xfs_btree_bload_level_geometry(cur, bbl, level, nr_this_level, &avg_per_block, &level_blocks, &dontcare64);
@@ -718,6 +719,7 @@ xfs_btree_bload_compute_geometry( /* Otherwise, we need another level of btree. */ cur->bc_nlevels++; + ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS); } nr_blocks += level_blocks;