On Fri, Jul 29, 2016 at 7:57 PM, Vegard Nossum <vegard.nossum@xxxxxxxxxx> wrote: > Hi guys, > > I ran into this one on commit c624c86615fb8aa61fa76ed8c935446d06c80e77: > > ------------[ cut here ]------------ > kernel BUG at mm/mempolicy.c:1699! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > CPU: 1 PID: 27676 Comm: trinity-c0 Not tainted 4.7.0+ #64 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > Ubuntu-1.8.2-1ubuntu1 04/01/2014 > task: ffff88010b055a00 task.stack: ffff880101fb0000 > RIP: 0010:[<ffffffff8146246b>] [<ffffffff8146246b>] > policy_zonelist+0xab/0x1a0 > RSP: 0018:ffff880101fb7838 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: 0000000002000200 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: ffff880103ef0690 RDI: ffff880103ef0694 > RBP: ffff880101fb7858 R08: 000000000000000b R09: 0000000000000001 > R10: 000000007d18a1c3 R11: 00000000b63bb1ad R12: 0000000002000200 > R13: ffff88010b055a00 R14: 0000000000000000 R15: ffff880103ef0694 > FS: 00007f405819e700(0000) GS:ffff88011ac80000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000001746770 CR3: 0000000004218000 CR4: 00000000000006e4 > Stack: > ffff880103ef0690 0000000002000200 ffff880103ef0690 0000000002000200 > ffff880101fb78c0 ffffffff8146893a ffff880101fb78d0 0000000000015320 > ffff88010b055a00 0000000000000000 ffff88010b056968 00000002030594a7 > Call Trace: > [<ffffffff8146893a>] alloc_pages_current+0xba/0x370 > [<ffffffff81e136d4>] depot_save_stack+0x3f4/0x490 > [<ffffffff81476a65>] save_stack+0xb5/0xd0 > [<ffffffff814770dc>] kasan_slab_free+0x9c/0xd0 > [<ffffffff814734ef>] kmem_cache_free+0xaf/0x2b0 > [<ffffffff81465429>] __mpol_put+0x19/0x20 > [<ffffffff81109c95>] do_exit+0x1515/0x2c90 > [<ffffffff812bf16e>] seccomp_phase1+0x68e/0x830 > [<ffffffff8100476c>] syscall_trace_enter_phase1+0x24c/0x500 > [<ffffffff81004fe4>] syscall_trace_enter+0x64/0xb0 > [<ffffffff81005586>] do_syscall_64+0x336/0x460 > [<ffffffff8389f42a>] entry_SYSCALL64_slow_path+0x25/0x25 > Code: db 0f 95 c0 48 89 c1 48 c1 e0 0b 48 c1 e1 04 48 89 ca 4a 03 14 e5 c0 > 58 84 84 48 83 c4 10 5b 41 5c 5d 48 8d 84 02 00 15 00 00 c3 <0f> 0b 48 8d 7e > 06 48 b8 00 00 00 00 00 fc ff df 48 89 f9 48 c1 > RIP [<ffffffff8146246b>] policy_zonelist+0xab/0x1a0 > RSP <ffff880101fb7838> > ---[ end trace a30466557ef07873 ]--- > > That's: > > $ addr2line -e runs/1469799091/vmlinux -i ffffffff8146246b ffffffff8146893a > ffffffff81e136d4 ffffffff81476a65 ffffffff814770dc ffffffff814734ef > ffffffff81465429 ffffffff81109c95 ffffffff812bf16e > /home/vegard/linux/mm/mempolicy.c:1699 > /home/vegard/linux/mm/mempolicy.c:2072 > /home/vegard/linux/lib/stackdepot.c:247 > /home/vegard/linux/mm/kasan/kasan.c:491 > /home/vegard/linux/mm/kasan/kasan.c:496 > /home/vegard/linux/mm/kasan/kasan.c:547 > /home/vegard/linux/mm/slub.c:2940 > /home/vegard/linux/mm/slub.c:2957 > /home/vegard/linux/mm/mempolicy.c:300 > /home/vegard/linux/kernel/exit.c:854 > /home/vegard/linux/include/linux/audit.h:325 > /home/vegard/linux/kernel/seccomp.c:536 > /home/vegard/linux/kernel/seccomp.c:656 > > In particular, it's interesting that the kernel/exit.c line is > > mpol_put(tsk->mempolicy); > > and alloc_pages_current() does (potentially): > > pol = get_task_policy(current);. > > The bug seems very new or very rare or both. This is https://github.com/google/kasan/issues/35 It is introduced with stackdepot. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>