linux-kernel - [PATCH v3 06/48] maple_tree: Fix mas_prev() and mas

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 17 Jan 2023 02:34:11 +0000
From:   Liam Howlett <liam.howlett@...cle.com>
To:     "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        "maple-tree@...ts.infradead.org" <maple-tree@...ts.infradead.org>
CC:     Liam Howlett <liam.howlett@...cle.com>,
        "syzbot+502859d610c661e56545@...kaller.appspotmail.com" 
        <syzbot+502859d610c661e56545@...kaller.appspotmail.com>
Subject: [PATCH v3 06/48] maple_tree: Fix mas_prev() and mas_find() state
 handling

From: "Liam R. Howlett" <Liam.Howlett@...cle.com>

When mas_prev() does not find anything, set the state to MAS_NONE.

Handle the MAS_NONE in mas_find() like a MAS_START.

Reported-by: syzbot+502859d610c661e56545@...kaller.appspotmail.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@...cle.com>
---
 lib/maple_tree.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 03429149870c..667a4a46b024 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4855,7 +4855,7 @@ static inline void *mas_prev_entry(struct ma_state *mas, unsigned long min)
 
 	if (mas->index < min) {
 		mas->index = mas->last = min;
-		mas_pause(mas);
+		mas->node = MAS_NONE;
 		return NULL;
 	}
 retry:
@@ -5924,6 +5924,7 @@ void *mas_prev(struct ma_state *mas, unsigned long min)
 	if (!mas->index) {
 		/* Nothing comes before 0 */
 		mas->last = 0;
+		mas->node = MAS_NONE;
 		return NULL;
 	}
 
@@ -6014,6 +6015,9 @@ void *mas_find(struct ma_state *mas, unsigned long max)
 		mas->index = ++mas->last;
 	}
 
+	if (unlikely(mas_is_none(mas)))
+		mas->node = MAS_START;
+
 	if (unlikely(mas_is_start(mas))) {
 		/* First run or continue */
 		void *entry;
-- 
2.35.1