Messages in this thread | | | Subject | Re: WARNING: kmalloc bug in xdp_umem_create | From | Tetsuo Handa <> | Date | Sun, 10 Jun 2018 21:53:07 +0900 |
| |
On 2018/06/10 20:52, Dmitry Vyukov wrote: > On Sun, Jun 10, 2018 at 11:31 AM, Björn Töpel <bjorn.topel@gmail.com> wrote: >> Den sön 10 juni 2018 kl 04:53 skrev Tetsuo Handa >> <penguin-kernel@i-love.sakura.ne.jp>: >>> >>> On 2018/06/10 7:47, syzbot wrote: >>>> Hello, >>>> >>>> syzbot found the following crash on: >>>> >>>> HEAD commit: 7d3bf613e99a Merge tag 'libnvdimm-for-4.18' of git://git.k.. >>>> git tree: upstream >>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1073f68f800000 >>>> kernel config: https://syzkaller.appspot.com/x/.config?x=f04d8d0a2afb789a >>>> dashboard link: https://syzkaller.appspot.com/bug?extid=4abadc5d69117b346506 >>>> compiler: gcc (GCC) 8.0.1 20180413 (experimental) >>>> syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=13c9756f800000 >>>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16366f9f800000 >>>> >>>> IMPORTANT: if you fix the bug, please add the following tag to the commit: >>>> Reported-by: syzbot+4abadc5d69117b346506@syzkaller.appspotmail.com >>>> >>>> random: sshd: uninitialized urandom read (32 bytes read) >>>> random: sshd: uninitialized urandom read (32 bytes read) >>>> random: sshd: uninitialized urandom read (32 bytes read) >>>> random: sshd: uninitialized urandom read (32 bytes read) >>>> random: sshd: uninitialized urandom read (32 bytes read) >>>> WARNING: CPU: 1 PID: 4537 at mm/slab_common.c:996 kmalloc_slab+0x56/0x70 mm/slab_common.c:996 >>>> Kernel panic - not syncing: panic_on_warn set ... >>> >>> syzbot gave up upon kmalloc(), but actually error handling path has >>> NULL pointer dereference bug. >>> >> >> Thanks Tetsuo! This crash has been fixed by Daniel Borkmann in commit >> c09290c56376 ("bpf, xdp: fix crash in xdp_umem_unaccount_pages"). > > Let's tell syzbot about this: > > #syz fix: bpf, xdp: fix crash in xdp_umem_unaccount_pages > > Excuse me, but that patch fixes NULL pointer dereference which occurs after kmalloc()'s "WARNING: CPU: 1 PID: 4537 at mm/slab_common.c:996 kmalloc_slab+0x56/0x70 mm/slab_common.c:996" message. That is, "Too large memory allocation" itself is not yet fixed.
| |