(cc'ing Kent, hi!) On Mon, Aug 05, 2013 at 10:49:33AM -0400, Sasha Levin wrote: > Hi all, > > While fuzzing with trinity inside a KVM tools guest running latest -next kernel, > I've stumbled on the following spew: > > [ 274.820724] ------------[ cut here ]------------ > [ 274.821320] kernel BUG at mm/percpu.c:579! Looks like double free. > [ 274.821848] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC > [ 274.822467] Modules linked in: > [ 274.823240] CPU: 13 PID: 58 Comm: rcuos/13 Tainted: G W > 3.11.0-rc4-next-20130805-sasha-00002-gf6cc217 #3975 > [ 274.824464] task: ffff880220cb3000 ti: ffff880220cba000 task.ti: ffff880220cba000 > [ 274.825442] RIP: 0010:[<ffffffff812417b8>] [<ffffffff812417b8>] pcpu_free_area+0xd8/0x1e0 > [ 274.826470] RSP: 0018:ffff880220cbbc58 EFLAGS: 00010002 > [ 274.827316] RAX: ffff8800c9e3abd4 RBX: 00000000000002f5 RCX: 00000000000002f5 > [ 274.828162] RDX: 0000000000000004 RSI: 000000000000ede0 RDI: 000000000000ede0 > [ 274.829270] RBP: ffff880220cbbc78 R08: 0000000000000324 R09: ffff8800c9e3a000 > [ 274.830102] R10: ffff8800c9e3a000 R11: 0000000000000000 R12: ffff88022049ff80 > [ 274.830102] R13: 0000000000000bd4 R14: 0000000000000012 R15: ffffffff86612060 > [ 274.831367] FS: 0000000000000000(0000) GS:ffff880226000000(0000) knlGS:0000000000000000 > [ 274.831367] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 274.831367] CR2: 0000000001253028 CR3: 0000000214aff000 CR4: 00000000000006e0 > [ 274.831367] Stack: > [ 274.831367] 0000000000000282 000000000000ede0 ffff88022049ff80 000060fdd980ede0 > [ 274.831367] ffff880220cbbca8 ffffffff81241c7e ffff880220cbbca8 ffff8800b80f83e0 > [ 274.831367] 0000000000000000 ffff8800b80f83c0 ffff880220cbbd18 ffffffff81a14ea6 > [ 274.831367] Call Trace: > [ 274.831367] [<ffffffff81241c7e>] free_percpu+0x9e/0x160 > [ 274.831367] [<ffffffff81a14ea6>] percpu_ref_kill_rcu+0xb6/0x1b0 >From percpu_ref release path. Kent? > [ 274.831367] [<ffffffff8114e390>] ? wake_up_bit+0x40/0x40 > [ 274.831367] [<ffffffff81a14df0>] ? percpu_ref_init+0x50/0x50 > [ 274.831367] [<ffffffff811d4169>] rcu_nocb_kthread+0x449/0x520 > [ 274.831367] [<ffffffff8114e390>] ? wake_up_bit+0x40/0x40 > [ 274.831367] [<ffffffff811d3d20>] ? rcu_adopt_orphan_cbs+0x250/0x250 > [ 274.831367] [<ffffffff8114dac7>] kthread+0xe7/0xf0 > [ 274.831367] [<ffffffff81197a2a>] ? __lock_release+0x1da/0x1f0 > [ 274.831367] [<ffffffff8114d9e0>] ? __init_kthread_worker+0x70/0x70 > [ 274.831367] [<ffffffff840a132c>] ret_from_fork+0x7c/0xb0 > [ 274.831367] [<ffffffff8114d9e0>] ? __init_kthread_worker+0x70/0x70 > [ 274.831367] Code: 39 f7 74 0f 0f 0b 0f 1f 44 00 00 eb fe 66 0f 1f > 44 00 00 4d 89 ca 48 63 cb 4c 8d 2c 8d 00 00 00 00 4b 8d 04 2a 8b 10 > 85 d2 7e 10 <0f> 0b 66 0f 1f 44 00 00 eb fe 66 0f 1f 44 00 00 f7 da > 89 10 49 > [ 274.850289] RIP [<ffffffff812417b8>] pcpu_free_area+0xd8/0x1e0 > [ 274.850289] RSP <ffff880220cbbc58> > [ 274.850289] ---[ end trace 47f7ab405c6aeff4 ]--- > > > Thanks, > Sasha -- tejun -- To unsubscribe from this list: send the line "unsubscribe trinity" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html