Re: ptrace: gpf in syscall_trace_enter

Sasha Levin
2014-05-07T02:50:45Z

On 05/06/2014 08:36 PM, Sasha Levin wrote:
> Hi all,
>
> While fuzzing with trinity inside a KVM tools guest running the latest -next
> kernel I've stumbled on the following spew:

And another similar trace:

[ 6897.628729] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 6897.629654] Dumping ftrace buffer:
[ 6897.630034] (ftrace buffer empty)
[ 6897.630034] Modules linked in:
[ 6897.630034] CPU: 24 PID: 23736 Comm: trinity-c148 Tainted: G B 3.15.0-rc4-next-20140506-sasha-00021-gc164334-dirty #447
[ 6897.630034] task: ffff88002a870000 ti: ffff88000ef04000 task.ti: ffff88000ef04000
[ 6897.630034] RIP: syscall_trace_leave (include/trace/events/syscalls.h:42 arch/x86/kernel/ptrace.c:1517)
[ 6897.630034] RSP: 0000:ffff88000ef05f20 EFLAGS: 00010286
[ 6897.630034] RAX: 0000000000000000 RBX: ffff88000ef05f58 RCX: 0000000000000001
[ 6897.630034] RDX: fffffffffffffff2 RSI: ffff88000ef05f58 RDI: 6b6b6b6b6b6b6b6b
[ 6897.630034] RBP: ffff88000ef05f40 R08: ffff880218c3c498 R09: 0000000100290024
[ 6897.630034] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8806c5d04630
[ 6897.630034] R13: fffffffffffffff2 R14: 00000000000032e0 R15: 00000000000000af
[ 6897.630034] FS: 00007f5541eec700(0000) GS:ffff880587000000(0000) knlGS:0000000000000000
[ 6897.630034] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 6897.630034] CR2: 00007fff1ac95d78 CR3: 00000000036a0000 CR4: 00000000000006a0
[ 6897.630034] DR0: 00000000006df000 DR1: 0000000000000000 DR2: 0000000000000000
[ 6897.630034] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000000000f0602
[ 6897.630034] Stack:
[ 6897.630034] 00007f5541f0e2e0 00000000006e2000 00007f5541f0e2e0 0000000000000094
[ 6897.630034] 0000000000000011 ffffffffb458577f 000000001008feff 00000000000000af
[ 6897.630034] 00000000000032e0 0000000000000094 00007f5541f0e2e0 0000000000000011
[ 6897.630034] Call Trace:
[ 6897.630034] int_check_syscall_exit_work (arch/x86/kernel/entry_64.S:795)
[ 6897.630034] Code: 05 d1 9d f0 05 01 e8 2d 2e 14 00 4d 85 e4 75 10 65 ff 0c 25 a0 da 00 00 0f 84 85 00 00 00 eb 1c 49 8b 7c 24 08 4c 89 ea 48 89 de <41> ff 14 24 49 83 c4 10 49 83 3c 24 00 75 e6 eb d4 0f 1f 40 00
[ 6897.630034] RIP syscall_trace_leave (include/trace/events/syscalls.h:42 arch/x86/kernel/ptrace.c:1517)
[ 6897.630034] RSP <ffff88000ef05f20>

Thanks,
Sasha