On Fri, Mar 24, 2017 at 4:18 AM, Zefan Li <[email protected]> wrote: > On 2017/3/23 22:04, Dmitry Vyukov wrote: >> Hello, >> >> The following program triggers WARNING in percpu_ref_kill_and_confirm: >> https://gist.githubusercontent.com/dvyukov/bcfcef3d6b24b9fd841b88ee20c14d4b/raw/a54aeeb09ad1e0659b0ed87ef5efc4480ab2536f/gistfile1.txt >> > > The bug can be triggered immediately. I'll look into it. Thanks! Hi Zefan,
Have you had a chance to look into this bug? It's still reproducible for me with KMSAN. >> ------------[ cut here ]------------ >> WARNING: CPU: 3 PID: 19987 at lib/percpu-refcount.c:317 >> percpu_ref_kill_and_confirm+0x303/0x3c0 lib/percpu-refcount.c:316 >> percpu_ref_kill_and_confirm called more than once on css_release! >> CPU: 3 PID: 19987 Comm: a.out Not tainted 4.11.0-rc3+ #365 >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 >> Call Trace: >> __dump_stack lib/dump_stack.c:16 [inline] >> dump_stack+0x1b8/0x28d lib/dump_stack.c:52 >> panic+0x20c/0x423 kernel/panic.c:180 >> __warn+0x1c4/0x1e0 kernel/panic.c:541 >> warn_slowpath_fmt+0xc1/0x100 kernel/panic.c:564 >> percpu_ref_kill_and_confirm+0x303/0x3c0 lib/percpu-refcount.c:316 >> percpu_ref_kill include/linux/percpu-refcount.h:119 [inline] >> cgroup_kill_sb+0x31d/0x480 kernel/cgroup/cgroup.c:1834 >> deactivate_locked_super+0x99/0xe0 fs/super.c:309 >> deactivate_super+0x151/0x160 fs/super.c:340 >> cleanup_mnt+0xb2/0x160 fs/namespace.c:1115 >> __cleanup_mnt+0x16/0x20 fs/namespace.c:1122 >> task_work_run+0x1a4/0x270 kernel/task_work.c:116 >> tracehook_notify_resume include/linux/tracehook.h:191 [inline] >> exit_to_usermode_loop+0x24d/0x2d0 arch/x86/entry/common.c:161 >> prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline] >> syscall_return_slowpath+0x3bd/0x460 arch/x86/entry/common.c:260 >> entry_SYSCALL_64_fastpath+0xc0/0xc2 >> RIP: 0033:0x443129 >> RSP: 002b:00007ffe06080018 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 >> RAX: ffffffffffffffec RBX: 00000000004002b0 RCX: 0000000000443129 >> RDX: 000000002019cff9 RSI: 000000002000c000 RDI: 00000000204ff000 >> RBP: 00007ffe06080060 R08: 00000000201db000 R09: 0000000000000000 >> R10: 000000000000c084 R11: 0000000000000202 R12: 0000000000000000 >> R13: 00000000004025b0 R14: 0000000000402640 R15: 0000000000000000 >> >> On commit 093b995e3b55a0ae0670226ddfcb05bfbf0099ae >> . >> > > -- > You received this message because you are subscribed to the Google Groups > "syzkaller" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Matthew Scott Sucherman, Paul Terence Manicle Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
