Hi all,
While fuzzing with trinity inside a KVM tools running latest -next kernel I've stumbled on the
following spew:
[ 232.869443] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
[ 232.870230] IP: [<mm/page-writeback.c:1612>] balance_dirty_pages_ratelimited+0x1e/0x150
[ 232.870230] PGD 586e1d067 PUD 586e1e067 PMD 0
[ 232.870230] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 232.870230] Dumping ftrace buffer:
[ 232.870230] (ftrace buffer empty)
[ 232.870230] Modules linked in:
[ 232.870230] CPU: 36 PID: 9707 Comm: trinity-c36 Tainted: G W
3.14.0-rc4-next-20140225-sasha-00010-ga117461 #42
[ 232.870230] task: ffff880586dfb000 ti: ffff880586e34000 task.ti: ffff880586e34000
[ 232.870230] RIP: 0010:[<mm/page-writeback.c:1612>] [<mm/page-writeback.c:1612>]
balance_dirty_pages_ratelimited+0x1e/0x150
[ 232.870230] RSP: 0000:ffff880586e35c58 EFLAGS: 00010282
[ 232.870230] RAX: 0000000000000000 RBX: ffff880582831361 RCX: 0000000000000007
[ 232.870230] RDX: 0000000000000007 RSI: ffff880586dfbcc0 RDI: ffff880582831361
[ 232.870230] RBP: ffff880586e35c78 R08: 0000000000000000 R09: 0000000000000000
[ 232.870230] R10: 0000000000000001 R11: 0000000000000001 R12: 00007f58007ee000
[ 232.870230] R13: ffff880c8d6d4f70 R14: 0000000000000200 R15: ffff880c8dcce710
[ 232.870230] FS: 00007f58018bb700(0000) GS:ffff880c8e800000(0000) knlGS:0000000000000000
[ 232.870230] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 232.870230] CR2: 0000000000000020 CR3: 0000000586e1c000 CR4: 00000000000006e0
[ 232.870230] Stack:
[ 232.870230] ffff880586e35c78 ffff880586e33400 00007f58007ee000 ffff880c8d6d4f70
[ 232.870230] ffff880586e35cd8 ffffffff8127d241 0000000000000001 0000000000000001
[ 232.870230] 0000000000000000 ffffea0032337080 0000000080000000 ffff880586e33400
[ 232.870230] Call Trace:
[ 232.870230] [<mm/memory.c:3467>] do_shared_fault+0x1a1/0x1f0
[ 232.870230] [<mm/memory.c:3487>] handle_pte_fault+0xc8/0x230
[ 232.870230] [<arch/x86/include/asm/preempt.h:98>] ? delay_tsc+0xea/0x110
[ 232.870230] [<mm/memory.c:3770>] __handle_mm_fault+0x36e/0x3a0
[ 232.870230] [<include/linux/rcupdate.h:829>] ? rcu_read_unlock+0x5d/0x60
[ 232.870230] [<include/linux/memcontrol.h:148>] handle_mm_fault+0x10b/0x1b0
[ 232.870230] [<arch/x86/mm/fault.c:1147>] ? __do_page_fault+0x2e2/0x590
[ 232.870230] [<arch/x86/mm/fault.c:1214>] __do_page_fault+0x551/0x590
[ 232.870230] [<kernel/sched/cputime.c:681>] ? vtime_account_user+0x91/0xa0
[ 232.870230] [<arch/x86/include/asm/atomic.h:26>] ? context_tracking_user_exit+0xa8/0x1c0
[ 232.870230] [<arch/x86/include/asm/preempt.h:98>] ? _raw_spin_unlock+0x30/0x50
[ 232.870230] [<kernel/sched/cputime.c:681>] ? vtime_account_user+0x91/0xa0
[ 232.870230] [<arch/x86/include/asm/atomic.h:26>] ? context_tracking_user_exit+0xa8/0x1c0
[ 232.870230] [<arch/x86/include/asm/atomic.h:26>] do_page_fault+0x3d/0x70
[ 232.870230] [<arch/x86/kernel/kvm.c:263>] do_async_page_fault+0x35/0x100
[ 232.870230] [<arch/x86/kernel/entry_64.S:1496>] async_page_fault+0x28/0x30
[ 232.870230] Code: 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 48 83 ec 20 48 89 5d e8 4c
89 65 f0 4c 89 6d f8 48 89 fb 48 8b 87 50 01 00 00 <f6> 40 20 01 0f 85 18 01 00 00 65 48 8b 14 25 40
da 00 00 44 8b
[ 232.870230] RIP [<mm/page-writeback.c:1612>] balance_dirty_pages_ratelimited+0x1e/0x150
[ 232.870230] RSP <ffff880586e35c58>
[ 232.870230] CR2: 0000000000000020
Thanks,
Sasha
--
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>