6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> commit fb497d6db7c19c797cbd694b52d1af87c4eebcc6 upstream. 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. Link: https://lkml.kernel.org/r/20240905001204.1481-1-sj@xxxxxxxxxx Fixes: d0cf3dd47f0d ("damon: convert __damon_va_three_regions to use the VMA iterator") Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx> Closes: https://lore.kernel.org/b83651a0-5b24-4206-b860-cb54ffdf209b@xxxxxxxxxxxx Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- mm/damon/vaddr.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/damon/vaddr.c +++ b/mm/damon/vaddr.c @@ -126,6 +126,7 @@ static int __damon_va_three_regions(stru * 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(stru next: prev = vma; } + rcu_read_unlock(); if (!sz_range(&second_gap) || !sz_range(&first_gap)) return -EINVAL;
