On 1/3/19 9:42 AM, Dmitry Vyukov wrote: > On Thu, Jan 3, 2019 at 9:36 AM Vlastimil Babka <vbabka@xxxxxxx> wrote: >> >> >> On 12/31/18 8:51 AM, syzbot wrote: >>> Hello, >>> >>> syzbot found the following crash on: >>> >>> HEAD commit: 79fc24ff6184 kmsan: highmem: use kmsan_clear_page() in cop.. >>> git tree: kmsan >>> console output: https://syzkaller.appspot.com/x/log.txt?x=13c48b67400000 >>> kernel config: https://syzkaller.appspot.com/x/.config?x=901dd030b2cc57e7 >>> dashboard link: https://syzkaller.appspot.com/bug?extid=b19c2dc2c990ea657a71 >>> compiler: clang version 8.0.0 (trunk 349734) >>> >>> Unfortunately, I don't have any reproducer for this crash yet. >>> >>> IMPORTANT: if you fix the bug, please add the following tag to the commit: >>> Reported-by: syzbot+b19c2dc2c990ea657a71@xxxxxxxxxxxxxxxxxxxxxxxxx >>> >>> ================================================================== >>> BUG: KMSAN: uninit-value in mpol_rebind_policy mm/mempolicy.c:353 [inline] >>> BUG: KMSAN: uninit-value in mpol_rebind_mm+0x249/0x370 mm/mempolicy.c:384 >> >> The report doesn't seem to indicate where the uninit value resides in >> the mempolicy object. > > Yes, it doesn't and it's not trivial to do. The tool reports uses of > unint _values_. Values don't necessary reside in memory. It can be a > register, that come from another register that was calculated as a sum > of two other values, which may come from a function argument, etc. I see. BTW, the patch I sent will be picked up for testing, or does it have to be in mmotm/linux-next first?
