On Mon, 19 Feb 2024 02:35:20 -0500 "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > On Sun, Feb 18, 2024 at 09:06:18PM -0800, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: d37e1e4c52bc Add linux-next specific files for 20240216 > > git tree: linux-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=171ca652180000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=4bc446d42a7d56c0 > > dashboard link: https://syzkaller.appspot.com/bug?extid=6f3c38e8a6a0297caa5a > > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > > > > Downloadable assets: > > disk image: https://storage.googleapis.com/syzbot-assets/14d0894504b9/disk-d37e1e4c.raw.xz > > vmlinux: https://storage.googleapis.com/syzbot-assets/6cda61e084ee/vmlinux-d37e1e4c.xz > > kernel image: https://storage.googleapis.com/syzbot-assets/720c85283c05/bzImage-d37e1e4c.xz > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+6f3c38e8a6a0297caa5a@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ... > > > usbcore: registered new interface driver port100 > > usbcore: registered new interface driver nfcmrvl > > Loading iSCSI transport class v2.0-870. > > virtio_scsi virtio0: 1/0/0 default/read/poll queues > > ------------[ cut here ]------------ > > refcount_t: decrement hit 0; leaking memory. > > WARNING: CPU: 0 PID: 1 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31 > > Modules linked in: > > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.8.0-rc4-next-20240216-syzkaller #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 > > RIP: 0010:refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31 > > Code: b2 00 00 00 e8 b7 94 f0 fc 5b 5d c3 cc cc cc cc e8 ab 94 f0 fc c6 05 c6 16 ce 0a 01 90 48 c7 c7 a0 5a fe 8b e8 67 69 b4 fc 90 <0f> 0b 90 90 eb d9 e8 8b 94 f0 fc c6 05 a3 16 ce 0a 01 90 48 c7 c7 > > RSP: 0000:ffffc90000066e10 EFLAGS: 00010246 > > RAX: 15c2c224c9b50400 RBX: ffff888020827d2c RCX: ffff8880162d8000 > > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > > RBP: 0000000000000004 R08: ffffffff8157b942 R09: fffffbfff1bf95cc > > R10: dffffc0000000000 R11: fffffbfff1bf95cc R12: ffffea000502fdc0 > > R13: ffffea000502fdc8 R14: 1ffffd4000a05fb9 R15: 0000000000000000 > > FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: ffff88823ffff000 CR3: 000000000df32000 CR4: 00000000003506f0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > Call Trace: > > <TASK> > > reset_page_owner include/linux/page_owner.h:24 [inline] > > free_pages_prepare mm/page_alloc.c:1140 [inline] > > __free_pages_ok+0xc42/0xd70 mm/page_alloc.c:1269 > > make_alloc_exact+0xc4/0x140 mm/page_alloc.c:4847 > > vring_alloc_queue drivers/virtio/virtio_ring.c:319 [inline] > > Wow this seems to be breakage deep in mm/ - all virtio does is > call alloc_pages_exact and that corrupts the refcounts? > Will the bot be performing a bisection? If not, can one please be performed?