[syzbot] [net?] [nfc?] KMSAN: uninit-value in nci_rsp_packet

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9f8413c4a66f Merge tag 'cgroup-for-6.8' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=154b0f30180000
kernel config: https://syzkaller.appspot.com/x/.config?x=656820e61b758b15
dashboard link: https://syzkaller.appspot.com/bug?extid=685805de744584f4d24b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/79d9f2f4b065/disk-9f8413c4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cbc68430d9c6/vmlinux-9f8413c4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9740ad9fc172/bzImage-9f8413c4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+685805...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in nci_core_init_rsp_packet_v2 net/nfc/nci/rsp.c:107 [inline]
BUG: KMSAN: uninit-value in nci_core_init_rsp_packet net/nfc/nci/rsp.c:131 [inline]
BUG: KMSAN: uninit-value in nci_rsp_packet+0x294d/0x29a0 net/nfc/nci/rsp.c:376
nci_core_init_rsp_packet_v2 net/nfc/nci/rsp.c:107 [inline]
nci_core_init_rsp_packet net/nfc/nci/rsp.c:131 [inline]
nci_rsp_packet+0x294d/0x29a0 net/nfc/nci/rsp.c:376
nci_rx_work+0x1f3/0x500 net/nfc/nci/core.c:1518
process_one_work kernel/workqueue.c:2633 [inline]
process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2706
worker_thread+0xf45/0x1490 kernel/workqueue.c:2787
kthread+0x3ed/0x540 kernel/kthread.c:388
ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

Uninit was created at:
slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768
slab_alloc_node mm/slub.c:3478 [inline]
kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523
kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560
__alloc_skb+0x318/0x740 net/core/skbuff.c:651
alloc_skb include/linux/skbuff.h:1286 [inline]
virtual_ncidev_write+0x6d/0x280 drivers/nfc/virtual_ncidev.c:120
vfs_write+0x48b/0x1200 fs/read_write.c:588
ksys_write+0x20f/0x4c0 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__x64_sys_write+0x93/0xd0 fs/read_write.c:652
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 0 PID: 5070 Comm: kworker/u4:3 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Workqueue: nfc2_nci_rx_wq nci_rx_work
=====================================================


---
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syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
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If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup

[xingwei lee]

Hello, I reproduced this bug with the following report.

=====================================================
BUG: KMSAN: uninit-value in nci_core_init_rsp_packet_v2

home/dubbo/foobar/685805de-running/kernel/net/nfc/nci/rsp.c:107

[inline]
BUG: KMSAN: uninit-value in nci_core_init_rsp_packet

home/dubbo/foobar/685805de-running/kernel/net/nfc/nci/rsp.c:131
[inline]
BUG: KMSAN: uninit-value in nci_rsp_packet+0x2c0d/0x2c70
home/dubbo/foobar/685805de-running/kernel/net/nfc/nci/rsp.c:376
nci_core_init_rsp_packet_v2
home/dubbo/foobar/685805de-running/kernel/net/nfc/nci/rsp.c:107
[inline]
nci_core_init_rsp_packet
home/dubbo/foobar/685805de-running/kernel/net/nfc/nci/rsp.c:131
[inline]
nci_rsp_packet+0x2c0d/0x2c70
home/dubbo/foobar/685805de-running/kernel/net/nfc/nci/rsp.c:376
nci_rx_work+0x207/0x560
home/dubbo/foobar/685805de-running/kernel/net/nfc/nci/core.c:1518
process_one_work
home/dubbo/foobar/685805de-running/kernel/kernel/workqueue.c:2633
[inline]
process_scheduled_works+0x12bc/0x2060
home/dubbo/foobar/685805de-running/kernel/kernel/workqueue.c:2706
worker_thread+0x1062/0x1630
home/dubbo/foobar/685805de-running/kernel/kernel/workqueue.c:2787
kthread+0x422/0x5a0
home/dubbo/foobar/685805de-running/kernel/kernel/kthread.c:388
ret_from_fork+0x7f/0xa0
home/dubbo/foobar/685805de-running/kernel/arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20
home/dubbo/foobar/685805de-running/kernel/arch/x86/entry/entry_64.S:242

Uninit was created at:
slab_post_alloc_hook+0x129/0xa70

home/dubbo/foobar/685805de-running/kernel/mm/slab.h:768
slab_alloc_node
home/dubbo/foobar/685805de-running/kernel/mm/slub.c:3478 [inline]
kmem_cache_alloc_node+0x5e9/0xb10
home/dubbo/foobar/685805de-running/kernel/mm/slub.c:3523
kmalloc_reserve+0x14d/0x500
home/dubbo/foobar/685805de-running/kernel/net/core/skbuff.c:560
__alloc_skb+0x34e/0x7d0
home/dubbo/foobar/685805de-running/kernel/net/core/skbuff.c:651
alloc_skb home/dubbo/foobar/685805de-running/kernel/./include/linux/skbuff.h:1286
[inline]
virtual_ncidev_write+0x78/0x2c0
home/dubbo/foobar/685805de-running/kernel/drivers/nfc/virtual_ncidev.c:120
vfs_write+0x4d3/0x1330
home/dubbo/foobar/685805de-running/kernel/fs/read_write.c:588
ksys_write+0x273/0x510
home/dubbo/foobar/685805de-running/kernel/fs/read_write.c:643
__do_sys_write home/dubbo/foobar/685805de-running/kernel/fs/read_write.c:655
[inline]
__se_sys_write home/dubbo/foobar/685805de-running/kernel/fs/read_write.c:652
[inline]
__x64_sys_write+0x9e/0xe0
home/dubbo/foobar/685805de-running/kernel/fs/read_write.c:652
do_syscall_x64 home/dubbo/foobar/685805de-running/kernel/arch/x86/entry/common.c:52
[inline]
do_syscall_64+0x6d/0x140
home/dubbo/foobar/685805de-running/kernel/arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
CPU: 1 PID: 11 Comm: kworker/u8:0 Not tainted 6.7.0-00562-g92
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 4
Workqueue: nfc2_nci_rx_wq nci_rx_work

If you fix this issue, please add the following tag to the commit:
Reported-by: xingwei lee <xrive...@gmail.com>

I use the same configuration with the syzbot instances.

HEAD commit: 9f8413c4a66f Merge tag 'cgroup-for-6.8' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=154b0f30180000
kernel config: https://syzkaller.appspot.com/x/.config?x=656820e61b758b15
dashboard link: https://syzkaller.appspot.com/bug?extid=685805de744584f4d24b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

=* repro.c =*
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#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);
}

#define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off))
#define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len) \
*(type*)(addr) = \
htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | \
(((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len))))

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;
}

const int kInitNetNsFd = 201;

static long syz_init_net_socket(volatile long domain,
volatile long type,
volatile long proto) {
return syscall(__NR_socket, domain, type, proto);
}

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[4] = {0xffffffffffffffff, 0x0, 0xffffffffffffffff, 0x0};

void execute_call(int call) {
intptr_t res = 0;
switch (call) {
case 0:
memcpy((void*)0x20000080, "/dev/virtual_nci\000", 17);
res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul,
/*file=*/0x20000080ul, /*flags=*/2ul, /*mode=*/0ul);
if (res != -1)
r[0] = res;
break;
case 1:
res = syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0, /*arg=*/0x200000c0ul);
if (res != -1)
r[1] = *(uint32_t*)0x200000c0;
break;
case 2:
res = -1;
res = syz_init_net_socket(/*domain=*/0x10, /*type=*/3, /*proto=*/0x10);
if (res != -1)
r[2] = res;
break;
case 3:
memcpy((void*)0x20000100, "nfc\000", 4);
res = -1;
res = syz_genetlink_get_family_id(/*name=*/0x20000100, /*fd=*/r[2]);
if (res != -1)
r[3] = res;
break;
case 4:
*(uint64_t*)0x20000140 = 0;
*(uint32_t*)0x20000148 = 0;
*(uint64_t*)0x20000150 = 0x20000180;
*(uint64_t*)0x20000180 = 0x200001c0;
*(uint32_t*)0x200001c0 = 0x1c;
*(uint16_t*)0x200001c4 = r[3];
*(uint16_t*)0x200001c6 = 1;
*(uint32_t*)0x200001c8 = 0;
*(uint32_t*)0x200001cc = 0;
*(uint8_t*)0x200001d0 = 2;
*(uint8_t*)0x200001d1 = 0;
*(uint16_t*)0x200001d2 = 0;
*(uint16_t*)0x200001d4 = 8;
*(uint16_t*)0x200001d6 = 1;
*(uint32_t*)0x200001d8 = r[1];
*(uint64_t*)0x20000188 = 0x1c;
*(uint64_t*)0x20000158 = 1;
*(uint64_t*)0x20000160 = 0;
*(uint64_t*)0x20000168 = 0;
*(uint32_t*)0x20000170 = 0;
syscall(__NR_sendmsg, /*fd=*/r[2], /*msg=*/0x20000140ul, /*f=*/0ul);
break;
case 5:
memcpy((void*)0x20000280, "\x40\x00\x00\x00\xe7", 5);
syscall(__NR_write, /*fd=*/r[0], /*data=*/0x20000280ul, /*len=*/6ul);
break;
case 6:
STORE_BY_BITMASK(uint8_t, , 0x20000a80, 0, 0, 4);
STORE_BY_BITMASK(uint8_t, , 0x20000a80, 0, 4, 1);
STORE_BY_BITMASK(uint8_t, , 0x20000a80, 2, 5, 3);
*(uint8_t*)0x20000a81 = 1;
*(uint8_t*)0x20000a82 = 0;
*(uint8_t*)0x20000a83 = 0;
*(uint32_t*)0x20000a84 = 0;
*(uint8_t*)0x20000a88 = 0;
*(uint8_t*)0x20000a89 = 0;
*(uint16_t*)0x20000a8a = 0;
*(uint8_t*)0x20000a8c = 0;
*(uint16_t*)0x20000a8d = 0;
*(uint8_t*)0x20000a8f = 0;
*(uint32_t*)0x20000a90 = 9;
syscall(__NR_write, /*fd=*/r[0], /*data=*/0x20000a80ul, /*len=*/0x14ul);
break;
}
}
int main(void) {
syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
/*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
/*offset=*/0ul);
syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul,
/*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
/*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
/*offset=*/0ul);
syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul,
/*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 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 for about 1minus, the bug triggered very
steady.
=* repro.txt =*
r0 = openat$nci(0xffffffffffffff9c, &(0x7f0000000080), 0x2, 0x0)
ioctl$IOCTL_GET_NCIDEV_IDX(r0, 0x0, &(0x7f00000000c0)=<r1=>0x0)
r2 = syz_init_net_socket$nl_generic(0x10, 0x3, 0x10)
r3 = syz_genetlink_get_family_id$nfc(&(0x7f0000000100), r2)
sendmsg$NFC_CMD_DEV_UP(r2, &(0x7f0000000140)={0x0, 0x0,
&(0x7f0000000180)={&(0x7f00000001c0)={0x1c, r3, 0x1, 0x0, 0x0, {},
[@NFC_ATTR_DEVICE_INDEX={0x8, 0x1, r1}]}, 0x1c}}, 0x0)
write$nci(r0, &(0x7f0000000280)=ANY=[@ANYBLOB="40000000e7"], 0x6)
write$nci(r0, &(0x7f0000000a80)=@NCI_OP_CORE_INIT_RSP={0x0, 0x0, 0x2,
0x1, 0x0, {{}, {0x0, 0x0, 0x0, 0x0, 0x0, 0x9}}}, 0x14)

and see also in
https://gist.github.com/xrivendell7/3c9698f97a9418451c49aa9e275f7c51

BTW, in the reproducing progress, I found this bug maybe very close to
the KMSAN: uninit-value in
nci_rx_work(https://syzkaller.appspot.com/bug?extid=d7b4dc6cd50410152534)
and KMSAN: uninit-value in
nci_ntf_packet(https://syzkaller.appspot.com/bug?extid=d7b4dc6cd50410152534),
since the console_log can also generate this two bugs.

I hope it helps.

Best regards
xingwei Lee