Following kernel crash noticed on linux next 20211019 tag. on x86, i386 and other architectures.

[ 15.197596] BUG: kernel NULL pointer dereference, address: 0000000000000290 [ 15.204577] #PF: supervisor read access in kernel mode [ 15.204581] #PF: error_code(0x0000) - not-present page [ 15.204585] PGD 0 P4D 0 [ 15.204592] Oops: 0000 [#1] PREEMPT SMP PTI [ 15.204597] CPU: 2 PID: 352 Comm: systemd-resolve Not tainted 5.15.0-rc6-next-20211019 #1 [ 15.204604] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.2 05/23/2018 [ 15.204607] RIP: 0010:selinux_ip_postroute_compat+0x55/0x110 [ 15.242847] Code: 48 89 45 e8 31 c0 48 83 7a 18 00 f3 48 ab 0f 84 96 00 00 00 48 8b 43 18 48 85 c0 74 0d 0f b6 48 12 80 f9 0c 0f 84 a9 00 00 00 <4c> 8b a0 90 02 00 00 48 8b 42 10 31 c9 48 89 df 48 89 75 98 4c 8d [ 15.261592] RSP: 0018:ffffb8fc0077f890 EFLAGS: 00010246 [ 15.266810] RAX: 0000000000000000 RBX: ffffa31a82ee7200 RCX: 0000000000000000 [ 15.273933] RDX: ffffb8fc0077fa18 RSI: ffffb8fc0077f8b8 RDI: ffffb8fc0077f8f0 [ 15.281059] RBP: ffffb8fc0077f908 R08: ffffb8fc0077f960 R09: 0000000000000000 [ 15.288180] R10: 0000000000000000 R11: ffffb8fc0077fb70 R12: ffffa31a82ee7200 [ 15.295305] R13: ffffb8fc0077fa18 R14: ffffa31a82ee7200 R15: ffffb8fc0077fa18 [ 15.302428] FS: 00007fc366df0840(0000) GS:ffffa31befb00000(0000) knlGS:0000000000000000 [ 15.310507] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.316242] CR2: 0000000000000290 CR3: 0000000107660002 CR4: 00000000003706e0 [ 15.323367] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 15.330492] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 15.337615] Call Trace: [ 15.340061] <TASK> [ 15.342157] ? alloc_skb_with_frags+0x4e/0x1b0 [ 15.346603] ? _copy_from_iter+0xcd/0x5f0 [ 15.350614] selinux_ip_postroute+0x18f/0x4a0 [ 15.354964] ? ip_generic_getfrag+0x53/0xe0 [ 15.359145] nf_hook_slow+0x44/0xb0 [ 15.362635] ip_mc_output+0x184/0x310 [ 15.366292] ? ip_frag_next+0x184/0x190 [ 15.370123] ? ip_fraglist_init+0xb0/0xb0 [ 15.374128] ip_send_skb+0x8b/0x90 [ 15.377533] udp_send_skb+0x166/0x390 [ 15.381192] udp_sendmsg+0x9a6/0xb80 [ 15.384769] ? ip_frag_init+0x60/0x60 [ 15.388427] ? sock_def_readable+0x50/0x90 [ 15.392517] ? unix_stream_sendmsg+0x5a3/0x640 [ 15.396956] ? __switch_to+0x12e/0x490 [ 15.400708] ? _copy_from_user+0x2e/0x60 [ 15.404633] inet_sendmsg+0x65/0x70 [ 15.408116] ? inet_sendmsg+0x65/0x70 [ 15.411776] sock_sendmsg+0x5e/0x70 [ 15.415267] ____sys_sendmsg+0x22d/0x280 [ 15.419192] ___sys_sendmsg+0x81/0xc0 [ 15.422851] ? preempt_count_sub+0xba/0x100 [ 15.427062] ? debug_smp_processor_id+0x17/0x20 [ 15.431595] ? get_nohz_timer_target+0x1b/0x1b0 [ 15.436128] ? timerqueue_add+0x6e/0xc0 [ 15.439968] ? _raw_spin_unlock_irqrestore+0x24/0x40 [ 15.444932] ? __fdget+0x13/0x20 [ 15.448156] ? do_epoll_wait+0x84/0x750 [ 15.451987] __sys_sendmsg+0x62/0xb0 [ 15.455557] ? syscall_trace_enter.constprop.0+0x14c/0x1e0 [ 15.461037] __x64_sys_sendmsg+0x1d/0x20 [ 15.464960] do_syscall_64+0x3b/0x90 [ 15.468531] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 15.473576] RIP: 0033:0x7fc36620b711 [ 15.477153] Code: b5 78 20 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b6 0f 1f 80 00 00 00 00 8b 05 da bc 20 00 85 c0 75 16 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 57 c3 66 0f 1f 44 00 00 41 54 41 89 d4 55 48 [ 15.495890] RSP: 002b:00007fff5eab9cd8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 15.503476] RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007fc36620b711 [ 15.510598] RDX: 0000000000000000 RSI: 00007fff5eab9d20 RDI: 000000000000000b [ 15.517721] RBP: 00007fff5eab9d20 R08: 00007fff5eab9e80 R09: 00000000000014eb [ 15.524845] R10: 0000000000003d34 R11: 0000000000000246 R12: 00007fff5eab9e80 [ 15.531971] R13: 0000000000000002 R14: 0000000000000002 R15: 000000000000000b [ 15.539096] </TASK> [ 15.541278] Modules linked in: x86_pkg_temp_thermal [ 15.546148] CR2: 0000000000000290 [ 15.549460] ---[ end trace 2e081564e8f528df ]--- [ 15.554069] RIP: 0010:selinux_ip_postroute_compat+0x55/0x110

Full log, https://qa-reports.linaro.org/lkft/linux-next-master-sanity/build/next-20211...

Build config: https://builds.tuxbuild.com/1ziJHznpBT84rIGZ2HgbY9CVlQ1/config

Reported-by: Linux Kernel Functional Testing lkft@linaro.org

steps to reproduce: https://builds.tuxbuild.com/1ziJHznpBT84rIGZ2HgbY9CVlQ1/tuxmake_reproducer.s...

-- Linaro LKFT https://lkft.linaro.org