From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx> Traversing VMAs of a given maple tree should be protected by rcu read lock. However, __damon_va_three_regions() is not doing the protection. Hold the lock. Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx> Closes: https://lore.kernel.org/b83651a0-5b24-4206-b860-cb54ffdf209b@xxxxxxxxxxxx Fixes: d0cf3dd47f0d ("damon: convert __damon_va_three_regions to use the VMA iterator") Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> --- mm/damon/vaddr.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c index b0e8b361891d..08cfd22b5249 100644 --- a/mm/damon/vaddr.c +++ b/mm/damon/vaddr.c @@ -126,6 +126,7 @@ static int __damon_va_three_regions(struct mm_struct *mm, * If this is too slow, it can be optimised to examine the maple * tree gaps. */ + rcu_read_lock(); for_each_vma(vmi, vma) { unsigned long gap; @@ -146,6 +147,7 @@ static int __damon_va_three_regions(struct mm_struct *mm, next: prev = vma; } + rcu_read_unlock(); if (!sz_range(&second_gap) || !sz_range(&first_gap)) return -EINVAL; -- 2.39.2
