Messages in this thread | | | Date | Wed, 31 Jan 2018 12:54:07 -0800 | From | Eric Biggers <> | Subject | Re: KASAN: use-after-free Read in __wake_up_common |
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+jasowang@redhat.com
On Mon, Jan 22, 2018 at 11:58:02AM -0800, syzbot wrote: > Hello, > > syzbot hit the following crash on upstream commit > 8dd903d2cf7b6dfe98be7c19f891882583c7266e (Fri Jan 19 23:20:00 2018 +0000) > Merge tag 'scsi-fixes' of > git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi > > So far this crash happened 211 times on linux-next, mmots, upstream. > C reproducer is attached. > syzkaller reproducer is attached. > 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+779c85f1b6798c06885b@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 __wake_up_common+0x670/0x780 > kernel/sched/wait.c:90 > Read of size 8 at addr ffff8801bcf80f08 by task syzkaller194205/3724 > > CPU: 0 PID: 3724 Comm: syzkaller194205 Not tainted 4.15.0-rc8+ #270 > 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 > __wake_up_common+0x670/0x780 kernel/sched/wait.c:90 > __wake_up_common_lock+0x1b4/0x310 kernel/sched/wait.c:125 > __wake_up+0xe/0x10 kernel/sched/wait.c:149 > eventfd_release+0x4a/0x60 fs/eventfd.c:112 > __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 > exit_task_work include/linux/task_work.h:22 [inline] > do_exit+0x9bb/0x1ad0 kernel/exit.c:865 > do_group_exit+0x149/0x400 kernel/exit.c:968 > get_signal+0x73f/0x16c0 kernel/signal.c:2335 > do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809 > exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158 > 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 > RIP: 0033:0x449ac9 > RSP: 002b:00007f0696bfbda8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca > RAX: 0000000000000000 RBX: 00000000006dbc24 RCX: 0000000000449ac9 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000006dbc24 > RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 6f68762f7665642f > R13: 006563696d2f7475 R14: 706e692f7665642f R15: 0000000000000008 > > Allocated by task 3724: > 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 3724: > 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 > exit_task_work include/linux/task_work.h:22 [inline] > do_exit+0x9bb/0x1ad0 kernel/exit.c:865 > do_group_exit+0x149/0x400 kernel/exit.c:968 > get_signal+0x73f/0x16c0 kernel/signal.c:2335 > do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809 > exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158 > 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 ffff8801bcf80c80 > which belongs to the cache kmalloc-65536 of size 65536 > The buggy address is located 648 bytes inside of > 65536-byte region [ffff8801bcf80c80, ffff8801bcf90c80) > The buggy address belongs to the page: > page:ffffea0006f3e000 count:1 mapcount:0 mapping:ffff8801bcf80c80 index:0x0 > compound_mapcount: 0 > flags: 0x2fffc0000008100(slab|head) > raw: 02fffc0000008100 ffff8801bcf80c80 0000000000000000 0000000100000001 > raw: ffffea0006f26820 ffffea0006f3e820 ffff8801dac02500 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801bcf80e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801bcf80e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8801bcf80f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8801bcf80f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801bcf81000: 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 syzkaller@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
This appears to be a vhost bug, fixed by the following patch queued in net-next:
#syz fix: vhost_net: stop device during reset owner
- Eric
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