Vulnerability Database

In the Linux kernel, the following vulnerability has been resolved:

debugobjects: Don't wake up kswapd from fill_pool()

syzbot is reporting a lockdep warning in fill_pool() because the allocation from debugobjects is using GFP_ATOMIC, which is (__GFP_HIGH | __GFP_KSWAPD_RECLAIM) and therefore tries to wake up kswapd, which acquires kswapd_wait::lock.

Since fill_pool() might be called with arbitrary locks held, fill_pool() should not assume that acquiring kswapd_wait::lock is safe.

Use __GFP_HIGH instead and remove __GFP_NORETRY as it is pointless for !__GFP_DIRECT_RECLAIM allocation.