Hi there, We are testing kernel 4.19.47 with some tools utilizing kprobe, resulting in panics that look like: [ 1085.318031] kernel tried to execute NX-protected page - exploit attempt? (uid: 65534) [ 1085.334028] BUG: unable to handle kernel paging request at ffffffffc0428000 [ 1085.349128] PGD 13a3e10067 P4D 13a3e10067 PUD 13a3e12067 PMD c1e860067 PTE 8000000bbd075061 [ 1085.365779] Oops: 0011 [#1] SMP KASAN PTI [ 1085.377879] CPU: 30 PID: 29734 Comm: nginx-fl Tainted: G B O 4.19.47-cloudflare-kasan-2019.6.0 #2019.6.0 [ 1085.396652] Hardware name: Quanta Computer Inc QuantaPlex T41S-2U/S2S-MB, BIOS S2S_3B10.03 06/21/2018 [ 1085.414041] RIP: 0010:0xffffffffc0428000 [ 1085.425965] Code: Bad RIP value. [ 1085.436832] RSP: 0018:ffff88a015e2fb18 EFLAGS: 00010246 [ 1085.449853] RAX: 0000000000000003 RBX: ffff889f73448900 RCX: 0000000000000218 [ 1085.464719] RDX: ffff889fe4893c00 RSI: 0000000000000002 RDI: ffff889f73448900 [ 1085.479626] RBP: ffff88a015e2fe18 R08: 0000000000000006 R09: 0000000000000000 [ 1085.494677] R10: 000000008a08850a R11: 0000000000000000 R12: ffff889f7344890c [ 1085.509890] R13: ffff889f73448c54 R14: ffff889f73448c7a R15: 0000000000002c19 [ 1085.525252] FS: 00007f51582f5680(0000) GS:ffff88a03fb80000(0000) knlGS:0000000000000000 [ 1085.541810] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1085.555812] CR2: ffffffffc0427fd6 CR3: 0000002039fee004 CR4: 00000000001606e0 [ 1085.571154] Call Trace: [ 1085.581676] ? tcp_set_state+0x5/0x5b0 [ 1085.593532] ? tcp_v4_connect+0xbd7/0x2000 [ 1085.605809] ? tcp_sk_init+0x1220/0x1220 [ 1085.617810] ? selinux_socket_connect_helper.isra.55+0x277/0x400 [ 1085.631808] ? sock_poll+0x218/0x300 [ 1085.643407] ? selinux_netcache_avc_callback+0x30/0x30 [ 1085.656701] ? __inet_stream_connect+0x630/0xbd0 [ 1085.669508] ? expand_files.part.9+0x640/0x640 [ 1085.682145] ? ipip_gro_complete+0x110/0x110 [ 1085.694627] ? __inet_stream_connect+0xbd0/0xbd0 [ 1085.707397] ? inet_stream_connect+0x53/0xa0 [ 1085.719830] ? __sys_connect+0x1f6/0x270 [ 1085.731964] ? __ia32_sys_accept+0xb0/0xb0 [ 1085.744201] ? mutex_lock+0x85/0xe0 [ 1085.755815] ? ep_show_fdinfo+0x3c0/0x3c0 [ 1085.767916] ? syscall_trace_enter+0x566/0xc30 [ 1085.780429] ? __x64_sys_epoll_ctl+0x237/0x1080 [ 1085.792883] ? exit_to_usermode_loop+0x140/0x140 [ 1085.805425] ? __audit_syscall_exit+0x73e/0xa30 [ 1085.817925] ? __x64_sys_connect+0x6f/0xb0 [ 1085.829915] ? do_syscall_64+0x8e/0x280 [ 1085.841539] ? prepare_exit_to_usermode+0xe1/0x140 [ 1085.854067] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1085.867000] Modules linked in: xt_length xt_connlimit nf_conncount xt_hashlimit iptable_security sch_fq md_mod dm_crypt algif_skcipher af_alg dm_mod dax ip6table_nat nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw xt_nat iptable_nat nf_nat_ipv4 nf_nat xt_TPROXY nf_tproxy_ipv6 nf_tproxy_ipv4 xt_connmark iptable_mangle xt_owner ip6table_filter ip6_tables xt_CT xt_socket nf_socket_ipv4 nf_socket_ipv6 iptable_raw nfnetlink_log xt_NFLOG xt_bpf xt_comment xt_conntrack xt_mark xt_multiport xt_set xt_tcpudp ipt_GLBREDIRECT(O) nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 fou ip6_udp_tunnel udp_tunnel iptable_filter bpfilter ip_set_hash_netport ip_set_hash_net ip_set_hash_ip ip_set nfnetlink sit ipip tunnel4 ip_tunnel tun 8021q garp stp mrp llc sb_edac x86_pkg_temp_thermal kvm_intel kvm irqbypass [ 1085.996378] crc32_pclmul crc32c_intel pcbc aesni_intel aes_x86_64 ipmi_ssif crypto_simd cryptd glue_helper intel_cstate intel_uncore sfc(O) intel_rapl_perf tpm_tis tpm_tis_core mdio tpm ipmi_si ipmi_devintf ipmi_msghandler efivarfs ip_tables x_tables Reproducible steps on my local machine are as follow: 1. Run kernel 4.19.47 2. We are going to test kprobe on tcp_set_state using https://github.com/iovisor/bcc/blob/master/tools/tcplife.py. But probably any workload utilizing kprobe would work - Run some workload that creating tcp connections. I'm runing `python -m SimpleHTTPServer` and `wrk -d60s -c10 http://localhost:8000` - Run the script https://github.com/iovisor/bcc/blob/master/tools/tcplife.py. Expect it to not crash the kernel and producing some output Reverting commit 8715ce033eb37f539e73b1570bf56404b21d46cd makes it work for me locally. I also tested kernel 5.2.0-rc3-00024-g788a024921c4 locally (latest Linus tree) and not seeing the issue, so maybe somewhere along the backporting process, we failed to backport all the required patches ? Cheers, Daniel.
