On Wed, Jan 24, 2018 at 11:57:01PM -0800, syzbot wrote: > Hello, > > syzbot hit the following crash on upstream commit > 1f07476ec143bbed7bf0b641749783b1094b4c4f (Tue Jan 23 20:45:40 2018 +0000) > Merge tag 'pci-v4.15-fixes-3' of > git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci > > So far this crash happened 6 times on upstream. > Unfortunately, I don't have any reproducer for this crash yet. > Raw console output is attached. > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+fbbedb95ed1d1e957...@syzkaller.appspotmail.com > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > ================================================================== > BUG: KASAN: use-after-free in __list_add_valid+0xb1/0xd0 lib/list_debug.c:23 > Read of size 8 at addr ffff8801bb5893d0 by task syz-executor1/28911 > > CPU: 0 PID: 28911 Comm: syz-executor1 Not tainted 4.15.0-rc9+ #277 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:53 > print_address_description+0x73/0x250 mm/kasan/report.c:252 > kasan_report_error mm/kasan/report.c:351 [inline] > kasan_report+0x25b/0x340 mm/kasan/report.c:409 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 > __list_add_valid+0xb1/0xd0 lib/list_debug.c:23 > __list_add include/linux/list.h:60 [inline] > list_add include/linux/list.h:79 [inline] > __add_wait_queue include/linux/wait.h:156 [inline] > add_wait_queue+0xcf/0x290 kernel/sched/wait.c:30 > vhost_poll_func+0x3d/0x50 drivers/vhost/vhost.c:165 > poll_wait include/linux/poll.h:46 [inline] > eventfd_poll+0xe8/0x1f0 fs/eventfd.c:123 > vhost_poll_start+0x97/0x1c0 drivers/vhost/vhost.c:212 > vhost_vring_ioctl+0xe28/0x19b0 drivers/vhost/vhost.c:1556 > vhost_net_ioctl+0x9df/0x1910 drivers/vhost/net.c:1320 > vfs_ioctl fs/ioctl.c:46 [inline] > do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 > SYSC_ioctl fs/ioctl.c:701 [inline] > SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 > entry_SYSCALL_64_fastpath+0x29/0xa0 > RIP: 0033:0x452f19 > RSP: 002b:00007f33da20dc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 00007f33da20e700 RCX: 0000000000452f19 > RDX: 00000000208ffff8 RSI: 000000004008af20 RDI: 0000000000000017 > RBP: 0000000000a2f850 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000 > R13: 0000000000a2f7cf R14: 00007f33da20e9c0 R15: 0000000000000006 > > Allocated by task 28878: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 > __do_kmalloc_node mm/slab.c:3672 [inline] > __kmalloc_node+0x47/0x70 mm/slab.c:3679 > kmalloc_node include/linux/slab.h:541 [inline] > kvmalloc_node+0x64/0xd0 mm/util.c:397 > kvmalloc include/linux/mm.h:541 [inline] > vhost_net_open+0x27/0x670 drivers/vhost/net.c:902 > misc_open+0x382/0x500 drivers/char/misc.c:154 > chrdev_open+0x257/0x730 fs/char_dev.c:417 > do_dentry_open+0x667/0xd40 fs/open.c:752 > vfs_open+0x107/0x220 fs/open.c:866 > do_last fs/namei.c:3379 [inline] > path_openat+0x1151/0x3530 fs/namei.c:3519 > do_filp_open+0x25b/0x3b0 fs/namei.c:3554 > do_sys_open+0x502/0x6d0 fs/open.c:1059 > SYSC_openat fs/open.c:1086 [inline] > SyS_openat+0x30/0x40 fs/open.c:1080 > entry_SYSCALL_64_fastpath+0x29/0xa0 > > Freed by task 28878: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 > __cache_free mm/slab.c:3488 [inline] > kfree+0xd6/0x260 mm/slab.c:3803 > kvfree+0x36/0x60 mm/util.c:416 > vhost_net_release+0x159/0x190 drivers/vhost/net.c:1012 > __fput+0x327/0x7e0 fs/file_table.c:210 > ____fput+0x15/0x20 fs/file_table.c:244 > task_work_run+0x199/0x270 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:191 [inline] > exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162 > prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] > syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 > entry_SYSCALL_64_fastpath+0x9e/0xa0 > > The buggy address belongs to the object at ffff8801bb589140 > which belongs to the cache kmalloc-65536 of size 65536 > The buggy address is located 656 bytes inside of > 65536-byte region [ffff8801bb589140, ffff8801bb599140) > The buggy address belongs to the page: > page:ffffea0006ed6000 count:1 mapcount:0 mapping:ffff8801bb589140 index:0x0 > compound_mapcount: 0 > flags: 0x2fffc0000008100(slab|head) > raw: 02fffc0000008100 ffff8801bb589140 0000000000000000 0000000100000001 > raw: ffffea00068b0820 ffffea000693d020 ffff8801dac02500 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801bb589280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801bb589300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8801bb589380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8801bb589400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801bb589480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkal...@googlegroups.com. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title
No reproducer for this one but I assume it was yet another report of the vhost_net bug fixed by commit 4cd879515d68: #syz fix: vhost_net: stop device during reset owner - Eric