#!/bin/sh # Fatal trap 12: page fault while in kernel mode # cpuid = 21; apic id = 29 # fault virtual address = 0x5eb9977d # fault code = supervisor read data, page not present # instruction pointer = 0x20:0xffffffff80d8f181 # stack pointer = 0x28:0xfffffe0126709300 # frame pointer = 0x28:0xfffffe0126709750 # code segment = base 0x0, limit 0xfffff, type 0x1b # = DPL 0, pres 1, long 1, def32 0, gran 1 # processor eflags = interrupt enabled, resume, IOPL = 0 # current process = 12 (swi1: netisr 0) # trap number = 12 # panic: page fault # cpuid = 21 # time = 1589220309 # KDB: stack backtrace: # db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe0126708fb0 # vpanic() at vpanic+0x182/frame 0xfffffe0126709000 # panic() at panic+0x43/frame 0xfffffe0126709060 # trap_fatal() at trap_fatal+0x387/frame 0xfffffe01267090c0 # trap_pfault() at trap_pfault+0x99/frame 0xfffffe0126709120 # trap() at trap+0x2a5/frame 0xfffffe0126709230 # calltrap() at calltrap+0x8/frame 0xfffffe0126709230 # --- trap 0xc, rip = 0xffffffff80d8f181, rsp = 0xfffffe0126709300, rbp = 0xfffffe0126709750 --- # sctp_process_control() at sctp_process_control+0x1351/frame 0xfffffe0126709750 # sctp_common_input_processing() at sctp_common_input_processing+0x4f1/frame 0xfffffe01267098c0 # sctp6_input_with_port() at sctp6_input_with_port+0x22c/frame 0xfffffe01267099b0 # sctp6_input() at sctp6_input+0xb/frame 0xfffffe01267099c0 # ip6_input() at ip6_input+0xe89/frame 0xfffffe0126709aa0 # swi_net() at swi_net+0x1a1/frame 0xfffffe0126709b20 # ithread_loop() at ithread_loop+0x279/frame 0xfffffe0126709bb0 # fork_exit() at fork_exit+0x80/frame 0xfffffe0126709bf0 # fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0126709bf0 # --- trap 0, rip = 0, rsp = 0, rbp = 0 --- # KDB: enter: panic # [ thread pid 12 tid 100083 ] # Stopped at kdb_enter+0x37: movq $0,0x10ca9a6(%rip) # db> # Reproduced on r360902 # Fixed by r360942 [ `uname -p` = "i386" ] && exit 0 . ../default.cfg kldstat -v | grep -q sctp || kldload sctp.ko cat > /tmp/syzkaller12.c < #include #include #include #include #include #include #include #include #include #include #include #include #include static void kill_and_wait(int pid, int* status) { kill(pid, SIGKILL); while (waitpid(-1, status, 0) != pid) { } } static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void execute_one(void); #define WAIT_FLAGS 0 static void loop(void) { int iter; for (iter = 0;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { execute_one(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5 * 1000) continue; kill_and_wait(pid, &status); break; } } } uint64_t r[1] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; res = syscall(SYS_socket, 0x1cul, 1ul, 0x84); if (res != -1) r[0] = res; *(uint8_t*)0x20000000 = 0x1c; *(uint8_t*)0x20000001 = 0x1c; *(uint16_t*)0x20000002 = htobe16(0x4e22); *(uint32_t*)0x20000004 = 0; *(uint8_t*)0x20000008 = 0; *(uint8_t*)0x20000009 = 0; *(uint8_t*)0x2000000a = 0; *(uint8_t*)0x2000000b = 0; *(uint8_t*)0x2000000c = 0; *(uint8_t*)0x2000000d = 0; *(uint8_t*)0x2000000e = 0; *(uint8_t*)0x2000000f = 0; *(uint8_t*)0x20000010 = 0; *(uint8_t*)0x20000011 = 0; *(uint8_t*)0x20000012 = 0; *(uint8_t*)0x20000013 = 0; *(uint8_t*)0x20000014 = 0; *(uint8_t*)0x20000015 = 0; *(uint8_t*)0x20000016 = 0; *(uint8_t*)0x20000017 = 0; *(uint32_t*)0x20000018 = 0; syscall(SYS_bind, r[0], 0x20000000ul, 0x1cul); *(uint8_t*)0x20000180 = 0x5f; *(uint8_t*)0x20000181 = 0x1c; *(uint16_t*)0x20000182 = htobe16(0x4e22); *(uint32_t*)0x20000184 = 0; *(uint64_t*)0x20000188 = htobe64(0); *(uint64_t*)0x20000190 = htobe64(1); *(uint32_t*)0x20000198 = 0; syscall(SYS_connect, r[0], 0x20000180ul, 0x1cul); } int main(void) { syscall(SYS_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x1012ul, -1, 0ul); loop(); return 0; } // https://syzkaller.a EOF mycc -o /tmp/syzkaller12 -Wall -Wextra -O2 /tmp/syzkaller12.c -lpthread || exit 1 (cd /tmp; ./syzkaller12) & sleep 60 pkill -9 syzkaller12 wait rm -f /tmp/syzkaller12 /tmp/syzkaller12.c /tmp/syzkaller12.core exit 0