Re: [lkp-robot] [KEYS] 98f7748967: BUG:unable_to_handle_kernel

From: Eric Biggers
Date: Mon May 08 2017 - 14:43:03 EST


On Mon, May 08, 2017 at 09:23:16AM +0800, kernel test robot wrote:
> [ 16.476188] BUG: unable to handle kernel NULL pointer dereference at (null)
> [ 16.478886] IP: memset_erms+0x9/0x10
> [ 16.480180] PGD a9a067
> [ 16.480181] PUD a9b067
> [ 16.481283] PMD 0
> [ 16.482389]
> [ 16.484358] Oops: 0002 [#1] SMP
> [ 16.485573] Modules linked in: pptp gre l2tp_ppp l2tp_netlink l2tp_core ip6_udp_tunnel udp_tunnel pppoe pppox ppp_generic slhc nfnetlink scsi_transport_iscsi dccp_ipv6 atm sctp dccp_ipv4 dccp
> [ 16.490424] CPU: 0 PID: 311 Comm: trinity-c2 Not tainted 4.11.0-rc4-00106-g98f7748 #1
> [ 16.493066] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
> [ 16.496072] task: ffff8800195425c0 task.stack: ffffc90000338000
> [ 16.499768] RIP: 0010:memset_erms+0x9/0x10
> [ 16.501145] RSP: 0018:ffffc9000033bea8 EFLAGS: 00010246
> [ 16.502717] RAX: ffffffffffffff00 RBX: 0000000000000000 RCX: 0000000000000001
> [ 16.504650] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000
> [ 16.506550] RBP: ffffc9000033beb8 R08: 0000000000000020 R09: 0000000000000000
> [ 16.508420] R10: 8080808080808080 R11: fefefefefefefeff R12: ffffffffffffff82
> [ 16.510312] R13: 0000000000000000 R14: 0000000000000000 R15: ffffffffffffff82
> [ 16.512193] FS: 0000000000000000(0000) GS:ffff88000be00000(0063) knlGS:0000000009cf1840
> [ 16.514822] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
> [ 16.516468] CR2: 0000000000000000 CR3: 0000000000a99000 CR4: 00000000001406f0
> [ 16.518369] Call Trace:
> [ 16.519468] ? memzero_explicit+0x12/0x20
> [ 16.520838] SyS_add_key+0x14c/0x1f0
> [ 16.522133] do_fast_syscall_32+0xab/0x250
> [ 16.523508] entry_SYSENTER_compat+0x4c/0x5b
> [ 16.524913] RIP: 0023:0xf77d5c99
> [ 16.526137] RSP: 002b:00000000ffccaf0c EFLAGS: 00000292 ORIG_RAX: 000000000000011e
> [ 16.544091] RAX: ffffffffffffffda RBX: 00000000080ecb3d RCX: 0000000000000000
> [ 16.545969] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00000000102100a5
> [ 16.547857] RBP: 0000000040000000 R08: 0000000000000000 R09: 0000000000000000
> [ 16.549732] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> [ 16.551615] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
> [ 16.553491] Code: 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01
> [ 16.558559] RIP: memset_erms+0x9/0x10 RSP: ffffc9000033bea8
> [ 16.560177] CR2: 0000000000000000
> [ 16.561464] ---[ end trace 9432180228dd30ad ]---

Nice to see this is getting tested! David, as I've said previously, and as I
noted in the commit message itself, this cannot be applied until "KEYS: fix
dereferencing NULL payload with nonzero length" has also been applied.

- Eric