On Tue, Jul 12, 2022 at 03:29:29PM +0200, Dmitry Vyukov wrote: > Then I think it's still possible that this is a KMEMLEAK false > positive. IIRC it may have some false positives since it does not do > full stop-the-world before scanning memory/registers. syzkaller tries > to circumvent this by doing multiple scans with some delays, but it > does not give 100% guarantee. > And I am assuming this code does not try to hide pointers by storing > something in low/high bits, etc. Oh, I meant to answer this. The XArray does set bit 1 of the pointer when it's stored in the tree. However, this shouldn't affect kmemleak (I would think) because it looks like a pointer to the third byte of the allocation, so the allocation is still referenced, even if the first byte of the allocation isn't referenced. Also, I would expect kmemleak to report bugs all over if this were the problem, because every node no matter how it's allocated gets its bit 1 set.
