NULL pointer dereference when loading the gre module (3.10.0-rc4)

From: Steinar H. Gunderson
Date: Thu Jun 06 2013 - 18:17:08 EST


Hi,

In 3.10.0-rc4, I get this on boot:

[ 16.871043] BUG: unable to handle kernel NULL pointer dereference at 0000000000000003
[ 16.879453] IP: [<ffffffffa0e52002>] 0xffffffffa0e52001
[ 16.884995] PGD 0
[ 16.887313] Oops: 0000 [#1] SMP
[ 16.890904] Modules linked in: ip_gre(+) gre ip_tunnel psmouse ide_generic ide_gd_mod ide_cd_mod cdrom acpi_cpufreq mperf coretemp kvm_intel kvm iTCO_wdt iTCO_vendor_support i2c_i801 microcode lpc_ich pcspkr i2c_core mfd_core ehci_pci evbug evdev ext4 crc16 jbd2 mbcache dm_mod raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq raid1 md_mod sg sd_mod usbhid ide_pci_generic ide_core crc32c_intel e1000e ata_piix ptp pps_core uhci_hcd ehci_hcd mpt2sas raid_class unix
[ 16.939181] CPU: 0 PID: 3261 Comm: modprobe Not tainted 3.10.0-rc4 #1
[ 16.945873] Hardware name: Supermicro X8DTL/X8DTL, BIOS 2.1a 12/30/2011
[ 16.953252] task: ffff880621662d60 ti: ffff8806227de000 task.ti: ffff8806227de000
[ 16.961184] RIP: 0010:[<ffffffffa0e52002>] [<ffffffffa0e52002>] 0xffffffffa0e52001
[ 16.969346] RSP: 0018:ffff8806227dfca8 EFLAGS: 00010246
[ 16.974903] RAX: ffffffffa0e5d000 RBX: ffff880623ebe280 RCX: 0000000000000000
[ 16.982285] RDX: ffffffffa0e5aa40 RSI: 0000000000000003 RDI: ffffffffa0e5d018
[ 16.989674] RBP: ffff8806227dfca8 R08: 000000000000072f R09: ffffffff812bae96
[ 16.997051] R10: ffffea00188d1200 R11: 0000000000000000 R12: ffff88061f874900
[ 17.004440] R13: ffffffffa0e5a9c0 R14: ffff8806227dfef8 R15: 0000000000000002
[ 17.011818] FS: 00007f7da1d97700(0000) GS:ffff880627200000(0000) knlGS:0000000000000000
[ 17.020357] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 17.026349] CR2: 0000000000000003 CR3: 0000000621b84000 CR4: 00000000000007f0
[ 17.033734] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 17.041110] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 17.048494] Stack:
[ 17.050757] ffff8806227dfcf8 ffffffff812baf26 2222222222222222 2222222222222222
[ 17.058857] 2222222222222222 ffffffffa0e5a9c0 0000000000000000 0000000000000000
[ 17.066933] ffff8806227dfef8 ffffffffa0e5ab60 ffff8806227dfd28 ffffffff812bafb6
[ 17.075008] Call Trace:
[ 17.077703] [<ffffffff812baf26>] ops_init.constprop.7+0xc6/0xf5
[ 17.083956] [<ffffffff812bafb6>] register_pernet_operations.isra.4+0x61/0x91
[ 17.091340] [<ffffffff8138486f>] ? mutex_lock+0xf/0x20
[ 17.096822] [<ffffffff812bb006>] register_pernet_device+0x20/0x51
[ 17.103254] [<ffffffffa0e5d034>] ? ipgre_tap_init_net+0x1a/0x1a [ip_gre]
[ 17.110298] [<ffffffffa0e5d055>] ipgre_init+0x21/0xc9 [ip_gre]
[ 17.116470] [<ffffffffa0e5d034>] ? ipgre_tap_init_net+0x1a/0x1a [ip_gre]
[ 17.123515] [<ffffffff81000263>] do_one_initcall+0x7b/0x10c
[ 17.129422] [<ffffffff8107e5db>] load_module+0x1b1f/0x1e19
[ 17.135241] [<ffffffff8107a4f8>] ? sys_getegid16+0x44/0x44
[ 17.141058] [<ffffffff81386cf2>] ? page_fault+0x22/0x30
[ 17.146618] [<ffffffff8107e969>] SyS_init_module+0x94/0xa1
[ 17.152440] [<ffffffff8138cf12>] system_call_fastpath+0x16/0x1b
[ 17.158695] Code: <6e> 65 77 6c 69 6e 6b 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 17.168440] RIP [<ffffffffa0e52002>] 0xffffffffa0e52001
[ 17.174058] RSP <ffff8806227dfca8>
[ 17.177798] CR2: 0000000000000003
[ 17.181730] ---[ end trace 531fea804a54bcad ]---

I assume this is from loading ip_gre, given that it's somewhere in the call
stack; amazingly enough, GRE tunnels seem to actually still work, though,
although I cannot load other modules such as ip_tables (modprobe hangs).

/* Steinar */
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Homepage: http://www.sesse.net/
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