Commit 17dc622c authored by Liam R. Howlett's avatar Liam R. Howlett Committed by Andrew Morton
Browse files

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

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


Signed-off-by: default avatarLiam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: default avatar <syzbot+502859d610c661e56545@syzkaller.appspotmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 1202700c

lib/maple_tree.c

+5 −1
Original line number Diff line number Diff line
@@ -4845,7 +4845,7 @@ 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:
@@ -5919,6 +5919,7 @@ 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;

	}
@@ -6009,6 +6010,9 @@ 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;