From: Wei Yang <richard.weiyang@gmail.com>
Date: Wed, 13 Nov 2024 03:16:16 +0000 (+0000)
Subject: maple_tree: only root node could be deficient
X-Git-Tag: v6.14-rc1~77^2~272
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7318f95ba40bed454d1e20f27e821198d3def4e5;p=thirdparty%2Flinux.git

maple_tree: only root node could be deficient

Each level's rightmost node should have (max == ULONG_MAX).  This means
current validation skips the right most node on each level.

Only the root node may be below the minimum data threshold.

Link: https://lkml.kernel.org/r/20241113031616.10530-4-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index ca8ae1e1cc0a5..f7153ade1be5f 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -7556,7 +7556,7 @@ void mt_validate(struct maple_tree *mt)
 		MAS_WARN_ON(&mas, mte_dead_node(mas.node));
 		end = mas_data_end(&mas);
 		if (MAS_WARN_ON(&mas, (end < mt_min_slot_count(mas.node)) &&
-				(mas.max != ULONG_MAX))) {
+				(!mte_is_root(mas.node)))) {
 			pr_err("Invalid size %u of " PTR_FMT "\n",
 			       end, mas_mn(&mas));
 		}