FYI, we noticed the below changes on https://github.com/0day-ci/linux Geliang-Tang/Bluetooth-use-list_for_each_entry/20151218-234306 commit c5e8d791cacac62eeec48e00a1a14a6a350670f4 ("ipv4, ipv6: use list_for_each_entry*") [ 6.848404] IPv6: Attempt to override permanent protocol 33 [ 6.850925] kworker/u2:1 (109) used greatest stack depth: 7240 bytes left [ 6.850925] kworker/u2:1 (109) used greatest stack depth: 7240 bytes left [ 6.880428] BUG: unable to handle kernel [ 6.880428] BUG: unable to handle kernel NULL pointer dereferenceNULL pointer dereference at (null) at (null) [ 6.882213] IP: [ 6.882213] IP: [] __list_del_entry+0x88/0x230 [] __list_del_entry+0x88/0x230 [ 6.883565] *pdpt = 0000000000000000 [ 6.883565] *pdpt = 0000000000000000 *pde = f000ff53f000ff53 *pde = f000ff53f000ff53 [ 6.885082] Oops: 0000 [#1] [ 6.885082] Oops: 0000 [#1] SMP SMP [ 6.885926] Modules linked in: [ 6.885926] Modules linked in: [ 6.886781] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.0-rc3-00302-gc5e8d79 #1 [ 6.886781] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.0-rc3-00302-gc5e8d79 #1 [ 6.888380] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 6.888380] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 6.890387] task: c005a000 ti: c005c000 task.ti: c005c000 [ 6.890387] task: c005a000 ti: c005c000 task.ti: c005c000 [ 6.891774] EIP: 0060:[] EFLAGS: 00010246 CPU: 0 [ 6.891774] EIP: 0060:[] EFLAGS: 00010246 CPU: 0 [ 6.895311] EIP is at __list_del_entry+0x88/0x230 [ 6.895311] EIP is at __list_del_entry+0x88/0x230 [ 6.896639] EAX: 00000000 EBX: cab7cd7c ECX: 00000000 EDX: 00000000 [ 6.896639] EAX: 00000000 EBX: cab7cd7c ECX: 00000000 EDX: 00000000 [ 6.899728] ESI: 00000000 EDI: 00000000 EBP: c005deec ESP: c005dec4 [ 6.899728] ESI: 00000000 EDI: 00000000 EBP: c005deec ESP: c005dec4 [ 6.903932] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 [ 6.903932] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 [ 6.905123] CR0: 80050033 CR2: 00000000 CR3: 0ade1000 CR4: 000406b0 [ 6.905123] CR0: 80050033 CR2: 00000000 CR3: 0ade1000 CR4: 000406b0 [ 6.909725] Stack: [ 6.909725] Stack: [ 6.910254] cab7a080 [ 6.910254] cab7a080 d5a87f88 d5a87f88 c005deec c005deec ca6cd52b ca6cd52b 00000000 00000000 00000001 00000001 00000000 00000000 cab7cd7c cab7cd7c [ 6.913171] cac4493e [ 6.913171] cac4493e d5a87f88 d5a87f88 c005df00 c005df00 ca590d75 ca590d75 ca5d25fd ca5d25fd ffffff9f ffffff9f ffffff9f ffffff9f c005df0c c005df0c [ 6.918206] cac4499f [ 6.918206] cac4499f caad4600 caad4600 c005df84 c005df84 c9c00442 c9c00442 024000c0 024000c0 ca9b99ac ca9b99ac cac4493e cac4493e 00000068 00000068 [ 6.921476] Call Trace: [ 6.921476] Call Trace: [ 6.922000] [] ? _raw_spin_lock_bh+0x6b/0x80 [ 6.922000] [] ? _raw_spin_lock_bh+0x6b/0x80 [ 6.924344] [] ? dccp_v6_init_net+0x30/0x30 [ 6.924344] [] ? dccp_v6_init_net+0x30/0x30 [ 6.925606] [] inet6_unregister_protosw+0x25/0x60 [ 6.925606] [] inet6_unregister_protosw+0x25/0x60 [ 6.930274] [] ? inet6_del_protocol+0x2d/0x40 [ 6.930274] [] ? inet6_del_protocol+0x2d/0x40 [ 6.931517] [] dccp_v6_init+0x61/0x70 [ 6.931517] [] dccp_v6_init+0x61/0x70 [ 6.932670] [] do_one_initcall+0x82/0x1e0 [ 6.932670] [] do_one_initcall+0x82/0x1e0 [ 6.937242] [] ? dccp_v6_init_net+0x30/0x30 [ 6.937242] [] ? dccp_v6_init_net+0x30/0x30 [ 6.939877] [] ? parse_args+0x176/0x440 [ 6.939877] [] ? parse_args+0x176/0x440 [ 6.940919] [] ? kernel_init_freeable+0xcd/0x16a [ 6.940919] [] ? kernel_init_freeable+0xcd/0x16a [ 6.942284] [] kernel_init_freeable+0xed/0x16a [ 6.942284] [] kernel_init_freeable+0xed/0x16a [ 6.946965] [] kernel_init+0x10/0xe0 [ 6.946965] [] kernel_init+0x10/0xe0 [ 6.948084] [] ret_from_kernel_thread+0x21/0x38 [ 6.948084] [] ret_from_kernel_thread+0x21/0x38 [ 6.952443] [] ? rest_init+0xc0/0xc0 [ 6.952443] [] ? rest_init+0xc0/0xc0 [ 6.953426] Code: [ 6.953426] Code: 78 78 69 69 bc bc ca ca 89 89 f2 f2 e8 e8 c8 c8 11 11 bb bb ff ff 81 81 7d 7d f0 f0 00 00 02 02 00 00 00 00 0f 0f 84 84 6b 6b 01 01 00 00 00 00 31 31 c9 c9 89 89 f2 f2 b8 b8 64 64 69 69 bc bc ca ca e8 e8 ad ad 11 11 bb bb ff ff 8b 8b 45 45 f0 f0 31 31 d2 d2 <8b> <8b> 30 30 b8 b8 50 50 69 69 bc bc ca ca 39 39 f3 f3 0f 0f 95 95 c2 c2 31 31 c9 c9 89 89 55 55 ec ec e8 e8 92 92 11 11 bb bb [ 6.965056] EIP: [] [ 6.965056] EIP: [] __list_del_entry+0x88/0x230__list_del_entry+0x88/0x230 SS:ESP 0068:c005dec4 SS:ESP 0068:c005dec4 [ 6.970187] CR2: 0000000000000000 [ 6.970187] CR2: 0000000000000000 [ 6.970894] ---[ end trace 2c9f823fcf08155b ]--- [ 6.970894] ---[ end trace 2c9f823fcf08155b ]--- Thanks, Kernel Test Robot