Patch "maple_tree: fix mas_prev() and mas_find() state handling" has been added to the 6.2-stable tree

[gregkh at linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    maple_tree: fix mas_prev() and mas_find() state handling

to the 6.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     maple_tree-fix-mas_prev-and-mas_find-state-handling.patch
and it can be found in the queue-6.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.


>From stable-owner at vger.kernel.org Tue Apr 11 17:13:01 2023
From: "Liam R. Howlett" <Liam.Howlett at oracle.com>
Date: Tue, 11 Apr 2023 11:10:46 -0400
Subject: maple_tree: fix mas_prev() and mas_find() state handling
To: Greg Kroah-Hartman <gregkh at linuxfoundation.org>, stable at vger.kernel.org
Cc: maple-tree at lists.infradead.org, linux-mm at kvack.org, linux-kernel at vger.kernel.org, "Liam R. Howlett" <Liam.Howlett at Oracle.com>, Stable at vger.kernel.org, "Liam R . Howlett" <Liam.Howlett at oracle.com>, syzbot+502859d610c661e56545 at syzkaller.appspotmail.com
Message-ID: <20230411151055.2910579-6-Liam.Howlett at oracle.com>

From: "Liam R. Howlett" <Liam.Howlett at Oracle.com>

commit 17dc622c7b0f94e49bed030726df4db12ecaa6b5 upstream.

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

Handle the MAS_NONE in mas_find() like a MAS_START.

Link: https://lkml.kernel.org/r/20230120162650.984577-7-Liam.Howlett@oracle.com
Cc: <Stable at vger.kernel.org>
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett at oracle.com>
Reported-by: <syzbot+502859d610c661e56545 at syzkaller.appspotmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 lib/maple_tree.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4849,7 +4849,7 @@ static inline void *mas_prev_entry(struc
 
 	if (mas->index < min) {
 		mas->index = mas->last = min;
-		mas_pause(mas);
+		mas->node = MAS_NONE;
 		return NULL;
 	}
 retry:
@@ -5911,6 +5911,7 @@ void *mas_prev(struct ma_state *mas, uns
 	if (!mas->index) {
 		/* Nothing comes before 0 */
 		mas->last = 0;
+		mas->node = MAS_NONE;
 		return NULL;
 	}
 
@@ -6001,6 +6002,9 @@ void *mas_find(struct ma_state *mas, uns
 		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;


Patches currently in stable-queue which might be from stable-owner at vger.kernel.org are

queue-6.2/maple_tree-fix-potential-rcu-issue.patch
queue-6.2/maple_tree-add-smp_rmb-to-dead-node-detection.patch
queue-6.2/maple_tree-add-rcu-lock-checking-to-rcu-callback-functions.patch
queue-6.2/maple_tree-fix-handle-of-invalidated-state-in-mas_wr_store_setup.patch
queue-6.2/maple_tree-reduce-user-error-potential.patch
queue-6.2/maple_tree-fix-mas_prev-and-mas_find-state-handling.patch
queue-6.2/maple_tree-remove-gfp_zero-from-kmem_cache_alloc-and-kmem_cache_alloc_bulk.patch
queue-6.2/maple_tree-be-more-cautious-about-dead-nodes.patch
queue-6.2/mm-enable-maple-tree-rcu-mode-by-default.patch
queue-6.2/maple_tree-detect-dead-nodes-in-mas_start.patch
queue-6.2/maple_tree-fix-freeing-of-nodes-in-rcu-mode.patch
queue-6.2/maple_tree-remove-extra-smp_wmb-from-mas_dead_leaves.patch
queue-6.2/maple_tree-refine-ma_state-init-from-mas_start.patch