From: Pravin B Shelar Date: Thu, 11 Jul 2013 18:38:06 +0000 (-0700) Subject: vxlan: Fix kernel crash on rmmod. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f89e57c4f5d7efdbe73b6214c73058aa335870e4;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git vxlan: Fix kernel crash on rmmod. vxlan exit module unregisters vxlan net and then it unregisters rtnl ops which triggers vxlan_dellink() from __rtnl_kill_links(). vxlan_dellink() deletes vxlan-dev from vxlan_list which has list-head in vxlan-net-struct but that is already gone due to net-unregister. That is how we are getting following crash. Following commit fixes the crash by fixing module exit path. BUG: unable to handle kernel paging request at ffff8804102c8000 IP: [] __list_del_entry+0x29/0xd0 PGD 2972067 PUD 83e019067 PMD 83df97067 PTE 80000004102c8060 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC Modules linked in: --- CPU: 19 PID: 6712 Comm: rmmod Tainted: GF 3.10.0+ #95 Hardware name: Dell Inc. PowerEdge R620/0KCKR5, BIOS 1.4.8 10/25/2012 task: ffff88080c47c580 ti: ffff88080ac50000 task.ti: ffff88080ac50000 RIP: 0010:[] [] __list_del_entry+0x29/0xd0 RSP: 0018:ffff88080ac51e08 EFLAGS: 00010206 RAX: ffff8804102c8000 RBX: ffff88040f0d4b10 RCX: dead000000200200 RDX: ffff8804102c8000 RSI: ffff88080ac51e58 RDI: ffff88040f0d4b10 RBP: ffff88080ac51e08 R08: 0000000000000001 R09: 2222222222222222 R10: 2222222222222222 R11: 2222222222222222 R12: ffff88080ac51e58 R13: ffffffffa07b8840 R14: ffffffff81ae48c0 R15: ffff88080ac51e58 FS: 00007f9ef105c700(0000) GS:ffff88082a800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8804102c8000 CR3: 00000008227e5000 CR4: 00000000000407e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff88080ac51e28 ffffffff812cc6a1 2222222222222222 ffff88040f0d4000 ffff88080ac51e48 ffffffffa07b3311 ffff88040f0d4000 ffffffff81ae49c8 ffff88080ac51e98 ffffffff81492fc2 ffff88080ac51e58 ffff88080ac51e58 Call Trace: [] list_del+0x11/0x40 [] vxlan_dellink+0x51/0x70 [vxlan] [] __rtnl_link_unregister+0xa2/0xb0 [] rtnl_link_unregister+0x1e/0x30 [] vxlan_cleanup_module+0x1c/0x2f [vxlan] [] SyS_delete_module+0x1d1/0x2c0 [] ? trace_hardirqs_on_thunk+0x3a/0x3f [] system_call_fastpath+0x16/0x1b Code: eb 9f 55 48 8b 17 48 b9 00 01 10 00 00 00 ad de 48 8b 47 08 48 89 e5 48 39 ca 74 29 48 b9 00 02 20 00 00 00 ad de 48 39 c8 74 7a <4c> 8b 00 4c 39 c7 75 53 4c 8b 42 08 4c 39 c7 75 2b 48 89 42 08 RIP [] __list_del_entry+0x29/0xd0 RSP CR2: ffff8804102c8000 Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller --- diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 227b54a1f88a..0ba1e7edbb1b 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1916,9 +1916,9 @@ late_initcall(vxlan_init_module); static void __exit vxlan_cleanup_module(void) { - unregister_pernet_device(&vxlan_net_ops); rtnl_link_unregister(&vxlan_link_ops); destroy_workqueue(vxlan_wq); + unregister_pernet_device(&vxlan_net_ops); rcu_barrier(); } module_exit(vxlan_cleanup_module);