Syzkaller hit 'memory leak in __anon_vma_prepare' bug. write to /proc/sys/net/core/bpf_jit_kallsyms failed: No such file or directory write to /proc/sys/net/core/bpf_jit_harden failed: No such file or directory BUG: memory leak unreferenced object 0xffff88801b906100 (size 192): comm "syz-executor190", pid 277, jiffies 4294843236 (age 24.460s) hex dump (first 32 bytes): 00 61 90 1b 80 88 ff ff 00 00 00 00 00 00 00 00 .a.............. 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<0000000089201997>] __anon_vma_prepare+0x279/0x4e0 [<0000000083b234b0>] __handle_mm_fault+0x2844/0x3650 [<00000000539ff8c2>] handle_mm_fault+0x2e6/0xa20 [<00000000d7ec9e5f>] __get_user_pages+0x50d/0x11b0 [<00000000f82664c9>] populate_vma_page_range+0x23d/0x320 [<000000001ecd9560>] __mm_populate+0xfe/0x3b0 [<0000000073853116>] do_mlock+0x2da/0x6e0 [<000000007d7f9bbc>] __x64_sys_mlock2+0xbd/0x100 [<00000000c33f2733>] do_syscall_64+0x3b/0x90 [<000000008950f38f>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 BUG: memory leak unreferenced object 0xffff88801b9e6480 (size 64): comm "syz-executor190", pid 277, jiffies 4294843239 (age 24.458s) hex dump (first 32 bytes): 80 56 9f 1b 80 88 ff ff 00 61 90 1b 80 88 ff ff .V.......a...... c8 56 9f 1b 80 88 ff ff c8 56 9f 1b 80 88 ff ff .V.......V...... backtrace: [<00000000d3a5800d>] anon_vma_clone+0xd3/0x560 [<000000001e573859>] copy_vma+0x3e0/0x7f0 [<00000000db2d7972>] move_vma.constprop.0+0x918/0xfa0 [<00000000111635a2>] __do_sys_mremap+0x74b/0x1470 [<00000000c33f2733>] do_syscall_64+0x3b/0x90 [<000000008950f38f>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 BUG: memory leak unreferenced object 0xffff88801b906000 (size 192): comm "syz-executor190", pid 278, jiffies 4294851388 (age 16.309s) hex dump (first 32 bytes): 00 60 90 1b 80 88 ff ff 00 00 00 00 00 00 00 00 .`.............. 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<0000000089201997>] __anon_vma_prepare+0x279/0x4e0 [<0000000083b234b0>] __handle_mm_fault+0x2844/0x3650 [<00000000539ff8c2>] handle_mm_fault+0x2e6/0xa20 [<00000000d7ec9e5f>] __get_user_pages+0x50d/0x11b0 [<00000000f82664c9>] populate_vma_page_range+0x23d/0x320 [<000000001ecd9560>] __mm_populate+0xfe/0x3b0 [<0000000073853116>] do_mlock+0x2da/0x6e0 [<000000007d7f9bbc>] __x64_sys_mlock2+0xbd/0x100 [<00000000c33f2733>] do_syscall_64+0x3b/0x90 [<000000008950f38f>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 BUG: memory leak unreferenced object 0xffff88801b9e65a0 (size 64): comm "syz-executor190", pid 278, jiffies 4294851390 (age 16.307s) hex dump (first 32 bytes): f0 e8 82 18 80 88 ff ff 00 60 90 1b 80 88 ff ff .........`...... 38 e9 82 18 80 88 ff ff 38 e9 82 18 80 88 ff ff 8.......8....... backtrace: [<00000000d3a5800d>] anon_vma_clone+0xd3/0x560 [<000000001e573859>] copy_vma+0x3e0/0x7f0 [<00000000db2d7972>] move_vma.constprop.0+0x918/0xfa0 [<00000000111635a2>] __do_sys_mremap+0x74b/0x1470 [<00000000c33f2733>] do_syscall_64+0x3b/0x90 [<000000008950f38f>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 write to /proc/sys/net/core/bpf_jit_kallsyms failed: No such file or directory write to /proc/sys/net/core/bpf_jit_harden failed: No such file or directory Syzkaller reproducer: # {Threaded:false Collide:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: Leak:true NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true UseTmpDir:false HandleSegv:false Repro:false Trace:false LegacyOptions:{Fault:false FaultCall:0 FaultNth:0}} mlock2(&(0x7f0000fef000/0x11000)=nil, 0x11000, 0x0) mremap(&(0x7f0000ff7000/0x2000)=nil, 0x2000, 0x2000, 0x7, &(0x7f0000ffe000/0x2000)=nil) (fail_nth: 30) C reproducer: // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include 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 bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } static int inject_fault(int nth) { int fd; fd = open("/proc/thread-self/fail-nth", O_RDWR); if (fd == -1) exit(1); char buf[16]; sprintf(buf, "%d", nth); if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)) exit(1); return fd; } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); for (int i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } } static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); } static void setup_fault() { static struct { const char* file; const char* val; bool fatal; } files[] = { {"/sys/kernel/debug/failslab/ignore-gfp-wait", "N", true}, {"/sys/kernel/debug/fail_futex/ignore-private", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-wait", "N", false}, {"/sys/kernel/debug/fail_page_alloc/min-order", "0", false}, }; unsigned i; for (i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].file, files[i].val)) { if (files[i].fatal) exit(1); } } } #define KMEMLEAK_FILE "/sys/kernel/debug/kmemleak" static void setup_leak() { if (!write_file(KMEMLEAK_FILE, "scan")) exit(1); sleep(5); if (!write_file(KMEMLEAK_FILE, "scan")) exit(1); if (!write_file(KMEMLEAK_FILE, "clear")) exit(1); } static void check_leaks(void) { int fd = open(KMEMLEAK_FILE, O_RDWR); if (fd == -1) exit(1); uint64_t start = current_time_ms(); if (write(fd, "scan", 4) != 4) exit(1); sleep(1); while (current_time_ms() - start < 4 * 1000) sleep(1); if (write(fd, "scan", 4) != 4) exit(1); static char buf[128 << 10]; ssize_t n = read(fd, buf, sizeof(buf) - 1); if (n < 0) exit(1); int nleaks = 0; if (n != 0) { sleep(1); if (write(fd, "scan", 4) != 4) exit(1); if (lseek(fd, 0, SEEK_SET) < 0) exit(1); n = read(fd, buf, sizeof(buf) - 1); if (n < 0) exit(1); buf[n] = 0; char* pos = buf; char* end = buf + n; while (pos < end) { char* next = strstr(pos + 1, "unreferenced object"); if (!next) next = end; char prev = *next; *next = 0; fprintf(stderr, "BUG: memory leak\n%s\n", pos); *next = prev; pos = next; nleaks++; } } if (write(fd, "clear", 5) != 5) exit(1); close(fd); if (nleaks) exit(1); } static void setup_sysctl() { char mypid[32]; snprintf(mypid, sizeof(mypid), "%d", getpid()); struct { const char* name; const char* data; } files[] = { {"/sys/kernel/debug/x86/nmi_longest_ns", "10000000000"}, {"/proc/sys/kernel/hung_task_check_interval_secs", "20"}, {"/proc/sys/net/core/bpf_jit_kallsyms", "1"}, {"/proc/sys/net/core/bpf_jit_harden", "0"}, {"/proc/sys/kernel/kptr_restrict", "0"}, {"/proc/sys/kernel/softlockup_all_cpu_backtrace", "1"}, {"/proc/sys/fs/mount-max", "100"}, {"/proc/sys/vm/oom_dump_tasks", "0"}, {"/proc/sys/debug/exception-trace", "0"}, {"/proc/sys/kernel/printk", "7 4 1 3"}, {"/proc/sys/net/ipv4/ping_group_range", "0 65535"}, {"/proc/sys/kernel/keys/gc_delay", "1"}, {"/proc/sys/vm/oom_kill_allocating_task", "1"}, {"/proc/sys/kernel/ctrl-alt-del", "0"}, {"/proc/sys/kernel/cad_pid", mypid}, }; for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].name, files[i].data)) printf("write to %s failed: %s\n", files[i].name, strerror(errno)); } } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { setup_test(); 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 < 5000) continue; kill_and_wait(pid, &status); break; } check_leaks(); } } #ifndef __NR_mlock2 #define __NR_mlock2 325 #endif void execute_one(void) { syscall(__NR_mlock2, 0x20fef000ul, 0x11000ul, 0ul); inject_fault(30); syscall(__NR_mremap, 0x20ff7000ul, 0x2000ul, 0x2000ul, 7ul, 0x20ffe000ul); } int main(void) { syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); setup_sysctl(); setup_leak(); setup_fault(); loop(); return 0; }