Hello, I reproduced this bug in the upstream linux. If you fix this issue, please add the following tag to the commit: Reported-by: xingwei lee <xrivendell7@xxxxxxxxx> Notice: I use the same config with syzbot dashboard. kernel version: 4f5e5092fdbf5cec6bedc19fbe69cce4f5f08372 kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=e3dd779fba027968 with KASAN enabled compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 BTW, I notice the frist patch apply in this bug: https://lore.kernel.org/all/ZdW9YBgTtaXo7DGQ@xxxxxxxxxxxxxxxxxxx/T/ and git apply this patch in the kernel. Since the reproducer is an infinite loop, I run the reproducer for about 20minus it doesn’t trigger the same issue. Anyway, the reproducer I’ll provided as below. =* repro.c =* // autogenerated by syzkaller (https://github.com/google/syzkaller) #include <arpa/inet.h> #include <dirent.h> #include <endian.h> #include <errno.h> #include <fcntl.h> #include <net/if.h> #include <netinet/in.h> #include <pthread.h> #include <signal.h> #include <stdarg.h> #include <stdbool.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/prctl.h> #include <sys/socket.h> #include <sys/stat.h> #include <sys/syscall.h> #include <sys/types.h> #include <sys/wait.h> #include <time.h> #include <unistd.h> #include <linux/futex.h> #include <linux/genetlink.h> #include <linux/if_addr.h> #include <linux/if_link.h> #include <linux/in6.h> #include <linux/neighbour.h> #include <linux/net.h> #include <linux/netlink.h> #include <linux/rtnetlink.h> #include <linux/veth.h> 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 thread_start(void* (*fn)(void*), void* arg) { pthread_t th; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); int i = 0; for (; i < 100; i++) { if (pthread_create(&th, &attr, fn, arg) == 0) { pthread_attr_destroy(&attr); return; } if (errno == EAGAIN) { usleep(50); continue; } break; } exit(1); } typedef struct { int state; } event_t; static void event_init(event_t* ev) { ev->state = 0; } static void event_reset(event_t* ev) { ev->state = 0; } static void event_set(event_t* ev) { if (ev->state) exit(1); __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000); } static void event_wait(event_t* ev) { while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0); } static int event_isset(event_t* ev) { return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE); } static int event_timedwait(event_t* ev, uint64_t timeout) { uint64_t start = current_time_ms(); uint64_t now = start; for (;;) { uint64_t remain = timeout - (now - start); struct timespec ts; ts.tv_sec = remain / 1000; ts.tv_nsec = (remain % 1000) * 1000 * 1000; syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts); if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) return 1; now = current_time_ms(); if (now - start > timeout) return 0; } } 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; } struct nlmsg { char* pos; int nesting; struct nlattr* nested[8]; char buf[4096]; }; static void netlink_init(struct nlmsg* nlmsg, int typ, int flags, const void* data, int size) { memset(nlmsg, 0, sizeof(*nlmsg)); struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf; hdr->nlmsg_type = typ; hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags; memcpy(hdr + 1, data, size); nlmsg->pos = (char*)(hdr + 1) + NLMSG_ALIGN(size); } static void netlink_attr(struct nlmsg* nlmsg, int typ, const void* data, int size) { struct nlattr* attr = (struct nlattr*)nlmsg->pos; attr->nla_len = sizeof(*attr) + size; attr->nla_type = typ; if (size > 0) memcpy(attr + 1, data, size); nlmsg->pos += NLMSG_ALIGN(attr->nla_len); } static int netlink_send_ext(struct nlmsg* nlmsg, int sock, uint16_t reply_type, int* reply_len, bool dofail) { if (nlmsg->pos > nlmsg->buf + sizeof(nlmsg->buf) || nlmsg->nesting) exit(1); struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf; hdr->nlmsg_len = nlmsg->pos - nlmsg->buf; struct sockaddr_nl addr; memset(&addr, 0, sizeof(addr)); addr.nl_family = AF_NETLINK; ssize_t n = sendto(sock, nlmsg->buf, hdr->nlmsg_len, 0, (struct sockaddr*)&addr, sizeof(addr)); if (n != (ssize_t)hdr->nlmsg_len) { if (dofail) exit(1); return -1; } n = recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0); if (reply_len) *reply_len = 0; if (n < 0) { if (dofail) exit(1); return -1; } if (n < (ssize_t)sizeof(struct nlmsghdr)) { errno = EINVAL; if (dofail) exit(1); return -1; } if (hdr->nlmsg_type == NLMSG_DONE) return 0; if (reply_len && hdr->nlmsg_type == reply_type) { *reply_len = n; return 0; } if (n < (ssize_t)(sizeof(struct nlmsghdr) + sizeof(struct nlmsgerr))) { errno = EINVAL; if (dofail) exit(1); return -1; } if (hdr->nlmsg_type != NLMSG_ERROR) { errno = EINVAL; if (dofail) exit(1); return -1; } errno = -((struct nlmsgerr*)(hdr + 1))->error; return -errno; } static int netlink_query_family_id(struct nlmsg* nlmsg, int sock, const char* family_name, bool dofail) { struct genlmsghdr genlhdr; memset(&genlhdr, 0, sizeof(genlhdr)); genlhdr.cmd = CTRL_CMD_GETFAMILY; netlink_init(nlmsg, GENL_ID_CTRL, 0, &genlhdr, sizeof(genlhdr)); netlink_attr(nlmsg, CTRL_ATTR_FAMILY_NAME, family_name, strnlen(family_name, GENL_NAMSIZ - 1) + 1); int n = 0; int err = netlink_send_ext(nlmsg, sock, GENL_ID_CTRL, &n, dofail); if (err < 0) { return -1; } uint16_t id = 0; struct nlattr* attr = (struct nlattr*)(nlmsg->buf + NLMSG_HDRLEN + NLMSG_ALIGN(sizeof(genlhdr))); for (; (char*)attr < nlmsg->buf + n; attr = (struct nlattr*)((char*)attr + NLMSG_ALIGN(attr->nla_len))) { if (attr->nla_type == CTRL_ATTR_FAMILY_ID) { id = *(uint16_t*)(attr + 1); break; } } if (!id) { errno = EINVAL; return -1; } recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0); return id; } static long syz_genetlink_get_family_id(volatile long name, volatile long sock_arg) { int fd = sock_arg; if (fd < 0) { fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC); if (fd == -1) { return -1; } } struct nlmsg nlmsg_tmp; int ret = netlink_query_family_id(&nlmsg_tmp, fd, (char*)name, false); if ((int)sock_arg < 0) close(fd); if (ret < 0) { return -1; } return ret; } 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"); } struct thread_t { int created, call; event_t ready, done; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { event_wait(&th->ready); event_reset(&th->ready); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); event_set(&th->done); } return 0; } static void execute_one(void) { int i, call, thread; for (call = 0; call < 7; call++) { for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0])); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; event_init(&th->ready); event_init(&th->done); event_set(&th->done); thread_start(thr, th); } if (!event_isset(&th->done)) continue; event_reset(&th->done); th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); event_set(&th->ready); event_timedwait(&th->done, 50); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); } 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; } } } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: res = syscall(__NR_socket, /*domain=*/0x26ul, /*type=*/5ul, /*proto=*/0); if (res != -1) r[0] = res; break; case 1: *(uint16_t*)0x20000000 = 0x26; memcpy((void*)0x20000002, "skcipher\000\000\000\000\000\000", 14); *(uint32_t*)0x20000010 = 0; *(uint32_t*)0x20000014 = 0; memcpy((void*)0x20000018, "cts(cbc(des3_ede))" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" "\000\000\000\000\000\000\000\000\000\000\000\000\000\000", 64); syscall(__NR_bind, /*fd=*/r[0], /*addr=*/0x20000000ul, /*addrlen=*/0x58ul); break; case 2: memcpy((void*)0x20c18000, "\xad\x56\xb6\xc5\x82\x0f\xae\x9d\x6d\xcd\x32\x92\xea\x54\xc7\xbe" "\xef\x91\x5d\x56\x4c\x90\xc2\x00", 24); syscall(__NR_setsockopt, /*fd=*/r[0], /*level=*/0x117, /*opt=*/1, /*key=*/0x20c18000ul, /*keylen=*/0x18ul); break; case 3: res = syscall(__NR_accept4, /*fd=*/r[0], /*peer=*/0ul, /*peerlen=*/0ul, /*flags=*/0ul); if (res != -1) r[1] = res; break; case 4: memcpy((void*)0x20000100, "nl80211\000", 8); syz_genetlink_get_family_id(/*name=*/0x20000100, /*fd=*/r[1]); break; case 5: *(uint64_t*)0x200001c0 = 0; *(uint32_t*)0x200001c8 = 0; *(uint64_t*)0x200001d0 = 0x20000180; *(uint64_t*)0x20000180 = 0x20000140; *(uint32_t*)0x20000140 = 0x28; *(uint16_t*)0x20000144 = 0; *(uint16_t*)0x20000146 = 0; *(uint32_t*)0x20000148 = 0; *(uint32_t*)0x2000014c = 0; *(uint8_t*)0x20000150 = 0x35; *(uint8_t*)0x20000151 = 0; *(uint16_t*)0x20000152 = 0; *(uint16_t*)0x20000154 = 8; *(uint16_t*)0x20000156 = 3; *(uint32_t*)0x20000158 = 0; *(uint16_t*)0x2000015c = 0xc; *(uint16_t*)0x2000015e = 0x99; *(uint32_t*)0x20000160 = 0; *(uint32_t*)0x20000164 = 0; *(uint64_t*)0x20000188 = 0x28; *(uint64_t*)0x200001d8 = 1; *(uint64_t*)0x200001e0 = 0; *(uint64_t*)0x200001e8 = 0; *(uint32_t*)0x200001f0 = 0; syscall(__NR_sendmsg, /*fd=*/r[1], /*msg=*/0x200001c0ul, /*f=*/0x8000ul); break; case 6: *(uint64_t*)0x20003fc0 = 0; *(uint32_t*)0x20003fc8 = 0; *(uint64_t*)0x20003fd0 = 0x20000080; *(uint64_t*)0x20000080 = 0x20000380; memcpy((void*)0x20000380, "\x05\xe2\x7d\x49\x1f\xdb\x75\x96\x99\x7a\xf6\xa7", 12); *(uint64_t*)0x20000088 = 0xc; *(uint64_t*)0x20003fd8 = 1; *(uint64_t*)0x20003fe0 = 0; *(uint64_t*)0x20003fe8 = 0; *(uint32_t*)0x20003ff0 = 0; *(uint32_t*)0x20003ff8 = 0; syscall(__NR_sendmmsg, /*fd=*/r[1], /*mmsg=*/0x20003fc0ul, /*vlen=*/1ul, /*f=*/0ul); break; } } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=*/7ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); loop(); return 0; } Remember to run this repro.txt with the command: syz-execprog -repeat 0 ./repro.txt and wait, the bug triggered very steady. =* repro.txt =* r0 = socket$alg(0x26, 0x5, 0x0) bind$alg(r0, &(0x7f0000000000)={0x26, 'skcipher\x00', 0x0, 0x0, 'cts(cbc(des3_ede))\x00'}, 0x58) setsockopt$ALG_SET_KEY(r0, 0x117, 0x1, &(0x7f0000c18000)="ad56b6c5820fae9d6dcd3292ea54c7beef915d564c90c200", 0x18) r1 = accept4(r0, 0x0, 0x0, 0x0) syz_genetlink_get_family_id$nl80211(&(0x7f0000000100), r1) sendmsg$NL80211_CMD_DEL_PMKSA(r1, &(0x7f00000001c0)={0x0, 0x0, &(0x7f0000000180)={&(0x7f0000000140)={0x28, 0x0, 0x0, 0x0, 0x0, {{}, {@val={0x8}, @val={0xc}}}}, 0x28}}, 0x8000) sendmmsg$unix(r1, &(0x7f0000003fc0)=[{{0x0, 0x0, &(0x7f0000000080)=[{&(0x7f0000000380)="05e27d491fdb7596997af6a7", 0xc}], 0x1}}], 0x1, 0x0) and see also in https://gist.github.com/xrivendell7/caa81fc506c57143468d8df12e099831. I hope it helps. Best regards! xingwei Lee
