2024-05-07 02:52:39

by lee bruce

Subject: WARNING in fuse_request_end

Hello, I found a new bug titled "WARNING in fuse_request_end" and
comfirmed in the lastest upstream.

If you fix this issue, please add the following tag to the commit:
Reported-by: xingwei lee <[email protected]>
Reported-by: yue sun <[email protected]>
kernel: upstream dccb07f2914cdab2ac3a5b6c98406f765acab803(lastest)
kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=7144b4fe7fbf5900
with KASAN enabled
compiler: gcc (GCC) 13.2.1 20231011

TITLE: WARNING in fuse_request_end
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8264 at fs/fuse/dev.c:300
fuse_request_end+0x685/0x7e0 fs/fuse/dev.c:300
Modules linked in:
CPU: 0 PID: 8264 Comm: ab2 Not tainted 6.9.0-rc7-00012-gdccb07f2914c #27
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.2-1.fc38 04/01/2014
RIP: 0010:fuse_request_end+0x685/0x7e0 fs/fuse/dev.c:300
Code: ff 3c 03 0f 8f d6 fd ff ff 4c 89 ff e8 24 31 f9 fe e9 c9 fd ff
ff e8 1a 8b 9c fe 90 0f 0b 90 e9 a9 fa ff ff e8 0c 8b 9c fe 90 <0f> 0b
90 e9 e6 fa ff ff 48 89 34 24 e8 fa 30 f9 fe 48 8b 34 24 e9
RSP: 0018:ffffc9000eb17a60 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8880342cc008 RCX: ffffffff82f20b6a
RDX: ffff88802fa79ec0 RSI: ffffffff82f21084 RDI: 0000000000000007
RBP: ffff8880342cc038 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000000 R12: ffff888029989000
R13: ffff88802cc39740 R14: 0000000000000100 R15: ffff8880342cc038
FS: 00007febdf6d96c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020002200 CR3: 000000001fe6c000 CR4: 0000000000750ef0
PKRU: 55555554
Call Trace:
<TASK>
fuse_dev_do_read.constprop.0+0xd36/0x1dd0 fs/fuse/dev.c:1334
fuse_dev_read+0x166/0x200 fs/fuse/dev.c:1367
call_read_iter include/linux/fs.h:2104 [inline]
new_sync_read fs/read_write.c:395 [inline]
vfs_read+0x85b/0xba0 fs/read_write.c:476
ksys_read+0x12f/0x260 fs/read_write.c:619
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xce/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x439ae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48
89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d
01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007febdf6d91f8 EFLAGS: 00000213 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007febdf6d96c0 RCX: 0000000000439ae9
RDX: 0000000000002020 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 00007febdf6d9220 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000213 R12: ffffffffffffffb0
R13: 000000000000006e R14: 00007ffde3c37740 R15: 00007ffde3c37828
</TASK>

=* repro.c =*
#define _GNU_SOURCE

#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <setjmp.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>

#include <linux/futex.h>
#include <linux/loop.h>

#ifndef __NR_memfd_create
#define __NR_memfd_create 319
#endif

static unsigned long long procid;

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;
}
}

//% This code is derived from puff.{c,h}, found in the zlib development. The
//% original files come with the following copyright notice:

//% Copyright (C) 2002-2013 Mark Adler, all rights reserved
//% version 2.3, 21 Jan 2013
//% This software is provided 'as-is', without any express or implied
//% warranty. In no event will the author be held liable for any damages
//% arising from the use of this software.
//% Permission is granted to anyone to use this software for any purpose,
//% including commercial applications, and to alter it and redistribute it
//% freely, subject to the following restrictions:
//% 1. The origin of this software must not be misrepresented; you must not
//% claim that you wrote the original software. If you use this software
//% in a product, an acknowledgment in the product documentation would be
//% appreciated but is not required.
//% 2. Altered source versions must be plainly marked as such, and must not be
//% misrepresented as being the original software.
//% 3. This notice may not be removed or altered from any source distribution.
//% Mark Adler [email protected]

//% BEGIN CODE DERIVED FROM puff.{c,h}

#define MAXBITS 15
#define MAXLCODES 286
#define MAXDCODES 30
#define MAXCODES (MAXLCODES + MAXDCODES)
#define FIXLCODES 288

struct puff_state {
unsigned char* out;
unsigned long outlen;
unsigned long outcnt;
const unsigned char* in;
unsigned long inlen;
unsigned long incnt;
int bitbuf;
int bitcnt;
jmp_buf env;
};
static int puff_bits(struct puff_state* s, int need)
{
long val = s->bitbuf;
while (s->bitcnt < need) {
if (s->incnt == s->inlen)
longjmp(s->env, 1);
val |= (long)(s->in[s->incnt++]) << s->bitcnt;
s->bitcnt += 8;
}
s->bitbuf = (int)(val >> need);
s->bitcnt -= need;
return (int)(val & ((1L << need) - 1));
}
static int puff_stored(struct puff_state* s)
{
s->bitbuf = 0;
s->bitcnt = 0;
if (s->incnt + 4 > s->inlen)
return 2;
unsigned len = s->in[s->incnt++];
len |= s->in[s->incnt++] << 8;
if (s->in[s->incnt++] != (~len & 0xff) ||
s->in[s->incnt++] != ((~len >> 8) & 0xff))
return -2;
if (s->incnt + len > s->inlen)
return 2;
if (s->outcnt + len > s->outlen)
return 1;
for (; len--; s->outcnt++, s->incnt++) {
if (s->in[s->incnt])
s->out[s->outcnt] = s->in[s->incnt];
}
return 0;
}
struct puff_huffman {
short* count;
short* symbol;
};
static int puff_decode(struct puff_state* s, const struct puff_huffman* h)
{
int first = 0;
int index = 0;
int bitbuf = s->bitbuf;
int left = s->bitcnt;
int code = first = index = 0;
int len = 1;
short* next = h->count + 1;
while (1) {
while (left--) {
code |= bitbuf & 1;
bitbuf >>= 1;
int count = *next++;
if (code - count < first) {
s->bitbuf = bitbuf;
s->bitcnt = (s->bitcnt - len) & 7;
return h->symbol[index + (code - first)];
}
index += count;
first += count;
first <<= 1;
code <<= 1;
len++;
}
left = (MAXBITS + 1) - len;
if (left == 0)
break;
if (s->incnt == s->inlen)
longjmp(s->env, 1);
bitbuf = s->in[s->incnt++];
if (left > 8)
left = 8;
}
return -10;
}
static int puff_construct(struct puff_huffman* h, const short* length, int n)
{
int len;
for (len = 0; len <= MAXBITS; len++)
h->count[len] = 0;
int symbol;
for (symbol = 0; symbol < n; symbol++)
(h->count[length[symbol]])++;
if (h->count[0] == n)
return 0;
int left = 1;
for (len = 1; len <= MAXBITS; len++) {
left <<= 1;
left -= h->count[len];
if (left < 0)
return left;
}
short offs[MAXBITS + 1];
offs[1] = 0;
for (len = 1; len < MAXBITS; len++)
offs[len + 1] = offs[len] + h->count[len];
for (symbol = 0; symbol < n; symbol++)
if (length[symbol] != 0)
h->symbol[offs[length[symbol]]++] = symbol;
return left;
}
static int puff_codes(struct puff_state* s, const struct puff_huffman* lencode,
const struct puff_huffman* distcode)
{
static const short lens[29] = {3, 4, 5, 6, 7, 8, 9, 10, 11, 13,
15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
67, 83, 99, 115, 131, 163, 195, 227, 258};
static const short lext[29] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2,
2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0};
static const short dists[30] = {
1, 2, 3, 4, 5, 7, 9, 13, 17, 25,
33, 49, 65, 97, 129, 193, 257, 385, 513, 769,
1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577};
static const short dext[30] = {0, 0, 0, 0, 1, 1, 2, 2, 3, 3,
4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 13, 13};
int symbol;
do {
symbol = puff_decode(s, lencode);
if (symbol < 0)
return symbol;
if (symbol < 256) {
if (s->outcnt == s->outlen)
return 1;
if (symbol)
s->out[s->outcnt] = symbol;
s->outcnt++;
} else if (symbol > 256) {
symbol -= 257;
if (symbol >= 29)
return -10;
int len = lens[symbol] + puff_bits(s, lext[symbol]);
symbol = puff_decode(s, distcode);
if (symbol < 0)
return symbol;
unsigned dist = dists[symbol] + puff_bits(s, dext[symbol]);
if (dist > s->outcnt)
return -11;
if (s->outcnt + len > s->outlen)
return 1;
while (len--) {
if (dist <= s->outcnt && s->out[s->outcnt - dist])
s->out[s->outcnt] = s->out[s->outcnt - dist];
s->outcnt++;
}
}
} while (symbol != 256);
return 0;
}
static int puff_fixed(struct puff_state* s)
{
static int virgin = 1;
static short lencnt[MAXBITS + 1], lensym[FIXLCODES];
static short distcnt[MAXBITS + 1], distsym[MAXDCODES];
static struct puff_huffman lencode, distcode;
if (virgin) {
lencode.count = lencnt;
lencode.symbol = lensym;
distcode.count = distcnt;
distcode.symbol = distsym;
short lengths[FIXLCODES];
int symbol;
for (symbol = 0; symbol < 144; symbol++)
lengths[symbol] = 8;
for (; symbol < 256; symbol++)
lengths[symbol] = 9;
for (; symbol < 280; symbol++)
lengths[symbol] = 7;
for (; symbol < FIXLCODES; symbol++)
lengths[symbol] = 8;
puff_construct(&lencode, lengths, FIXLCODES);
for (symbol = 0; symbol < MAXDCODES; symbol++)
lengths[symbol] = 5;
puff_construct(&distcode, lengths, MAXDCODES);
virgin = 0;
}
return puff_codes(s, &lencode, &distcode);
}
static int puff_dynamic(struct puff_state* s)
{
static const short order[19] = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5,
11, 4, 12, 3, 13, 2, 14, 1, 15};
int nlen = puff_bits(s, 5) + 257;
int ndist = puff_bits(s, 5) + 1;
int ncode = puff_bits(s, 4) + 4;
if (nlen > MAXLCODES || ndist > MAXDCODES)
return -3;
short lengths[MAXCODES];
int index;
for (index = 0; index < ncode; index++)
lengths[order[index]] = puff_bits(s, 3);
for (; index < 19; index++)
lengths[order[index]] = 0;
short lencnt[MAXBITS + 1], lensym[MAXLCODES];
struct puff_huffman lencode = {lencnt, lensym};
int err = puff_construct(&lencode, lengths, 19);
if (err != 0)
return -4;
index = 0;
while (index < nlen + ndist) {
int symbol;
int len;
symbol = puff_decode(s, &lencode);
if (symbol < 0)
return symbol;
if (symbol < 16)
lengths[index++] = symbol;
else {
len = 0;
if (symbol == 16) {
if (index == 0)
return -5;
len = lengths[index - 1];
symbol = 3 + puff_bits(s, 2);
} else if (symbol == 17)
symbol = 3 + puff_bits(s, 3);
else
symbol = 11 + puff_bits(s, 7);
if (index + symbol > nlen + ndist)
return -6;
while (symbol--)
lengths[index++] = len;
}
}
if (lengths[256] == 0)
return -9;
err = puff_construct(&lencode, lengths, nlen);
if (err && (err < 0 || nlen != lencode.count[0] + lencode.count[1]))
return -7;
short distcnt[MAXBITS + 1], distsym[MAXDCODES];
struct puff_huffman distcode = {distcnt, distsym};
err = puff_construct(&distcode, lengths + nlen, ndist);
if (err && (err < 0 || ndist != distcode.count[0] + distcode.count[1]))
return -8;
return puff_codes(s, &lencode, &distcode);
}
static int puff(unsigned char* dest, unsigned long* destlen,
const unsigned char* source, unsigned long sourcelen)
{
struct puff_state s = {
.out = dest,
.outlen = *destlen,
.outcnt = 0,
.in = source,
.inlen = sourcelen,
.incnt = 0,
.bitbuf = 0,
.bitcnt = 0,
};
int err;
if (setjmp(s.env) != 0)
err = 2;
else {
int last;
do {
last = puff_bits(&s, 1);
int type = puff_bits(&s, 2);
err = type == 0 ? puff_stored(&s)
: (type == 1 ? puff_fixed(&s)
: (type == 2 ? puff_dynamic(&s) : -1));
if (err != 0)
break;
} while (!last);
}
*destlen = s.outcnt;
return err;
}

//% END CODE DERIVED FROM puff.{c,h}

#define ZLIB_HEADER_WIDTH 2

static int puff_zlib_to_file(const unsigned char* source,
unsigned long sourcelen, int dest_fd)
{
if (sourcelen < ZLIB_HEADER_WIDTH)
return 0;
source += ZLIB_HEADER_WIDTH;
sourcelen -= ZLIB_HEADER_WIDTH;
const unsigned long max_destlen = 132 << 20;
void* ret = mmap(0, max_destlen, PROT_WRITE | PROT_READ,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (ret == MAP_FAILED)
return -1;
unsigned char* dest = (unsigned char*)ret;
unsigned long destlen = max_destlen;
int err = puff(dest, &destlen, source, sourcelen);
if (err) {
munmap(dest, max_destlen);
errno = -err;
return -1;
}
if (write(dest_fd, dest, destlen) != (ssize_t)destlen) {
munmap(dest, max_destlen);
return -1;
}
return munmap(dest, max_destlen);
}

static int setup_loop_device(unsigned char* data, unsigned long size,
const char* loopname, int* loopfd_p)
{
int err = 0, loopfd = -1;
int memfd = syscall(__NR_memfd_create, "syzkaller", 0);
if (memfd == -1) {
err = errno;
goto error;
}
if (puff_zlib_to_file(data, size, memfd)) {
err = errno;
goto error_close_memfd;
}
loopfd = open(loopname, O_RDWR);
if (loopfd == -1) {
err = errno;
goto error_close_memfd;
}
if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
if (errno != EBUSY) {
err = errno;
goto error_close_loop;
}
ioctl(loopfd, LOOP_CLR_FD, 0);
usleep(1000);
if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
err = errno;
goto error_close_loop;
}
}
close(memfd);
*loopfd_p = loopfd;
return 0;

error_close_loop:
close(loopfd);
error_close_memfd:
close(memfd);
error:
errno = err;
return -1;
}

static long syz_mount_image(volatile long fsarg, volatile long dir,
volatile long flags, volatile long optsarg,
volatile long change_dir,
volatile unsigned long size, volatile long image)
{
unsigned char* data = (unsigned char*)image;
int res = -1, err = 0, loopfd = -1, need_loop_device = !!size;
char* mount_opts = (char*)optsarg;
char* target = (char*)dir;
char* fs = (char*)fsarg;
char* source = NULL;
char loopname[64];
if (need_loop_device) {
memset(loopname, 0, sizeof(loopname));
snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid);
if (setup_loop_device(data, size, loopname, &loopfd) == -1)
return -1;
source = loopname;
}
mkdir(target, 0777);
char opts[256];
memset(opts, 0, sizeof(opts));
if (strlen(mount_opts) > (sizeof(opts) - 32)) {
}
strncpy(opts, mount_opts, sizeof(opts) - 32);
if (strcmp(fs, "iso9660") == 0) {
flags |= MS_RDONLY;
} else if (strncmp(fs, "ext", 3) == 0) {
bool has_remount_ro = false;
char* remount_ro_start = strstr(opts, "errors=remount-ro");
if (remount_ro_start != NULL) {
char after = *(remount_ro_start + strlen("errors=remount-ro"));
char before = remount_ro_start == opts ? '\0' : *(remount_ro_start - 1);
has_remount_ro = ((before == '\0' || before == ',') &&
(after == '\0' || after == ','));
}
if (strstr(opts, "errors=panic") || !has_remount_ro)
strcat(opts, ",errors=continue");
} else if (strcmp(fs, "xfs") == 0) {
strcat(opts, ",nouuid");
}
res = mount(source, target, fs, flags, opts);
if (res == -1) {
err = errno;
goto error_clear_loop;
}
res = open(target, O_RDONLY | O_DIRECTORY);
if (res == -1) {
err = errno;
goto error_clear_loop;
}
if (change_dir) {
res = chdir(target);
if (res == -1) {
err = errno;
}
}

error_clear_loop:
if (need_loop_device) {
ioctl(loopfd, LOOP_CLR_FD, 0);
close(loopfd);
}
errno = err;
return res;
}

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 loop(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);
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};

void execute_call(int call)
{
intptr_t res = 0;
switch (call) {
case 0:
memcpy((void*)0x20001cc0, "memory.events\000", 14);
res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x20001cc0ul,
/*flags=*/0x275aul, /*mode=*/0ul);
if (res != -1)
r[0] = res;
break;
case 1:
memcpy((void*)0x20000100, "/dev/fuse\000", 10);
res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul,
/*file=*/0x20000100ul, /*flags=*/2ul, /*mode=*/0ul);
if (res != -1)
r[1] = res;
break;
case 2:
memcpy((void*)0x20000080, "fuse\000", 5);
memcpy((void*)0x200000c0, "./file1\000", 8);
memcpy((void*)0x20006380, "fd", 2);
*(uint8_t*)0x20006382 = 0x3d;
sprintf((char*)0x20006383, "0x%016llx", (long long)r[1]);
*(uint8_t*)0x20006395 = 0x2c;
memcpy((void*)0x20006396, "rootmode", 8);
*(uint8_t*)0x2000639e = 0x3d;
sprintf((char*)0x2000639f, "%023llo", (long long)0x4000);
*(uint8_t*)0x200063b6 = 0x2c;
memcpy((void*)0x200063b7, "user_id", 7);
*(uint8_t*)0x200063be = 0x3d;
sprintf((char*)0x200063bf, "%020llu", (long long)0);
*(uint8_t*)0x200063d3 = 0x2c;
memcpy((void*)0x200063d4, "group_id", 8);
*(uint8_t*)0x200063dc = 0x3d;
sprintf((char*)0x200063dd, "%020llu", (long long)0);
*(uint8_t*)0x200063f1 = 0x2c;
*(uint8_t*)0x200063f2 = 0;
syz_mount_image(/*fs=*/0x20000080, /*dir=*/0x200000c0, /*flags=*/0,
/*opts=*/0x20006380, /*chdir=*/0, /*size=*/0, /*img=*/0);
break;
case 3:
syscall(__NR_read, /*fd=*/r[1], /*buf=*/0x20000140ul, /*len=*/0x2020ul);
break;
case 4:
*(uint32_t*)0x20002200 = 0x28;
*(uint32_t*)0x20002204 = 7;
*(uint64_t*)0x20002208 = 0;
*(uint64_t*)0x20002210 = 0;
*(uint64_t*)0x20002218 = 0;
*(uint64_t*)0x20002220 = 0;
syscall(__NR_write, /*fd=*/r[1], /*arg=*/0x20002200ul, /*len=*/0x28ul);
break;
case 5:
syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x3000ul, /*prot=*/0ul,
/*flags=*/0x12ul, /*fd=*/r[0], /*offset=*/0ul);
break;
case 6:
syscall(__NR_read, /*fd=*/r[1], /*buf=*/0x20000140ul, /*len=*/0x2020ul);
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;
}


=* repro.txt =*
r0 = openat$cgroup_ro(0xffffffffffffff9c,
&(0x7f0000001cc0)='memory.events\x00', 0x275a, 0x0)
r1 = openat$fuse(0xffffffffffffff9c, &(0x7f0000000100), 0x2, 0x0)
syz_mount_image$fuse(&(0x7f0000000080),
&(0x7f00000000c0)='./file1\x00', 0x0, &(0x7f0000006380)={{'fd', 0x3d,
r1}, 0x2c, {'rootmode', 0x3d, 0x4000}}, 0x0, 0x0, 0x0)
read$FUSE(r1, &(0x7f0000000140)={0x2020}, 0x2020)
write$FUSE_NOTIFY_INVAL_INODE(r1, &(0x7f0000002200)={0x28, 0x7}, 0x28)
mmap(&(0x7f0000000000/0x3000)=nil, 0x3000, 0x0, 0x12, r0, 0x0)
read$FUSE(r1, &(0x7f0000000140)={0x2020}, 0x2020)


Please also see:
https://gist.github.com/xrivendell7/346cb2c74cf5da4cad54cbdc8d1f0ded

I hope it helps.
Best regards.
xingwei Lee

2024-05-07 13:37:45

by Hou Tao

Subject: Re: WARNING in fuse_request_end

Hi,

On 5/7/2024 10:52 AM, lee bruce wrote:
> Hello, I found a new bug titled "WARNING in fuse_request_end" and
> comfirmed in the lastest upstream.
>
> If you fix this issue, please add the following tag to the commit:
> Reported-by: xingwei lee <[email protected]>
> Reported-by: yue sun <[email protected]>
> kernel: upstream dccb07f2914cdab2ac3a5b6c98406f765acab803(lastest)
> kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=7144b4fe7fbf5900
> with KASAN enabled
> compiler: gcc (GCC) 13.2.1 20231011
>
> TITLE: WARNING in fuse_request_end
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 8264 at fs/fuse/dev.c:300
> fuse_request_end+0x685/0x7e0 fs/fuse/dev.c:300
> Modules linked in:
> CPU: 0 PID: 8264 Comm: ab2 Not tainted 6.9.0-rc7-00012-gdccb07f2914c #27
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> 1.16.2-1.fc38 04/01/2014
> RIP: 0010:fuse_request_end+0x685/0x7e0 fs/fuse/dev.c:300
> Code: ff 3c 03 0f 8f d6 fd ff ff 4c 89 ff e8 24 31 f9 fe e9 c9 fd ff
> ff e8 1a 8b 9c fe 90 0f 0b 90 e9 a9 fa ff ff e8 0c 8b 9c fe 90 <0f> 0b
> 90 e9 e6 fa ff ff 48 89 34 24 e8 fa 30 f9 fe 48 8b 34 24 e9
> RSP: 0018:ffffc9000eb17a60 EFLAGS: 00010293
> RAX: 0000000000000000 RBX: ffff8880342cc008 RCX: ffffffff82f20b6a
> RDX: ffff88802fa79ec0 RSI: ffffffff82f21084 RDI: 0000000000000007
> RBP: ffff8880342cc038 R08: 0000000000000007 R09: 0000000000000000
> R10: 0000000000000100 R11: 0000000000000000 R12: ffff888029989000
> R13: ffff88802cc39740 R14: 0000000000000100 R15: ffff8880342cc038
> FS: 00007febdf6d96c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000020002200 CR3: 000000001fe6c000 CR4: 0000000000750ef0
> PKRU: 55555554
> Call Trace:
> <TASK>
> fuse_dev_do_read.constprop.0+0xd36/0x1dd0 fs/fuse/dev.c:1334
> fuse_dev_read+0x166/0x200 fs/fuse/dev.c:1367
> call_read_iter include/linux/fs.h:2104 [inline]
> new_sync_read fs/read_write.c:395 [inline]
> vfs_read+0x85b/0xba0 fs/read_write.c:476
> ksys_read+0x12f/0x260 fs/read_write.c:619
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xce/0x260 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x439ae9
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48
> 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d
> 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007febdf6d91f8 EFLAGS: 00000213 ORIG_RAX: 0000000000000000
> RAX: ffffffffffffffda RBX: 00007febdf6d96c0 RCX: 0000000000439ae9
> RDX: 0000000000002020 RSI: 0000000020000140 RDI: 0000000000000004
> RBP: 00007febdf6d9220 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000213 R12: ffffffffffffffb0
> R13: 000000000000006e R14: 00007ffde3c37740 R15: 00007ffde3c37828
> </TASK>
>
> =* repro.c =*

SNIP

> case 4:
> *(uint32_t*)0x20002200 = 0x28;
> *(uint32_t*)0x20002204 = 7;
> *(uint64_t*)0x20002208 = 0;
> *(uint64_t*)0x20002210 = 0;
> *(uint64_t*)0x20002218 = 0;
> *(uint64_t*)0x20002220 = 0;
> syscall(__NR_write, /*fd=*/r[1], /*arg=*/0x20002200ul, /*len=*/0x28ul);

Thanks for the report and the reproducer program.  It seems that the
warning is due to the FUSE_NOTIFY_RESEND notify send by the write()
syscall above and it happens as follows:

(1) the reproducer calls fuse_dev_read() to read the INIT request.
The read succeeds. During the read, bit FR_SENT will be set on req->flags.
(2) the reproducer calls fuse_dev_write() to write a FUSE_NOTIFY_RESEND
to resend all requests.
(3) the INIT request is moved from processing list to pending list again
(4) the reproducer calls fuse_dev_read() with an invalid output address
fuse_dev_read() will try to copy the INIT request to the output address,
but it fails,so the INIT request is ended and triggers the warning in
fuse_request_end().

A straightforward fix is to clear the FR_SENT bit in as show below:

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 3ec8bb5e68ff5..840cefdf24e26 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1814,6 +1814,7 @@ static void fuse_resend(struct fuse_conn *fc)

        list_for_each_entry_safe(req, next, &to_queue, list) {
                __set_bit(FR_PENDING, &req->flags);
+               clear_bit(FR_SENT, &req->flags);
                /* mark the request as resend request */
                req->in.h.unique |= FUSE_UNIQUE_RESEND;
        }

But I think more code checking and tests are needed before posting it as
a formal patch.

> break;
> case 5:
> syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x3000ul, /*prot=*/0ul,
> /*flags=*/0x12ul, /*fd=*/r[0], /*offset=*/0ul);
> break;
> case 6:
> syscall(__NR_read, /*fd=*/r[1], /*buf=*/0x20000140ul, /*len=*/0x2020ul);
> 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;
> }
>
>
> =* repro.txt =*
> r0 = openat$cgroup_ro(0xffffffffffffff9c,
> &(0x7f0000001cc0)='memory.events\x00', 0x275a, 0x0)
> r1 = openat$fuse(0xffffffffffffff9c, &(0x7f0000000100), 0x2, 0x0)
> syz_mount_image$fuse(&(0x7f0000000080),
> &(0x7f00000000c0)='./file1\x00', 0x0, &(0x7f0000006380)={{'fd', 0x3d,
> r1}, 0x2c, {'rootmode', 0x3d, 0x4000}}, 0x0, 0x0, 0x0)
> read$FUSE(r1, &(0x7f0000000140)={0x2020}, 0x2020)
> write$FUSE_NOTIFY_INVAL_INODE(r1, &(0x7f0000002200)={0x28, 0x7}, 0x28)
> mmap(&(0x7f0000000000/0x3000)=nil, 0x3000, 0x0, 0x12, r0, 0x0)
> read$FUSE(r1, &(0x7f0000000140)={0x2020}, 0x2020)
>
>
> Please also see:
> https://gist.github.com/xrivendell7/346cb2c74cf5da4cad54cbdc8d1f0ded
>
> I hope it helps.
> Best regards.
> xingwei Lee
>
> .

2024-05-08 08:30:50

by Miklos Szeredi

Subject: Re: WARNING in fuse_request_end

On Tue, 7 May 2024 at 15:30, Hou Tao <[email protected]> wrote:

> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index 3ec8bb5e68ff5..840cefdf24e26 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -1814,6 +1814,7 @@ static void fuse_resend(struct fuse_conn *fc)
>
> list_for_each_entry_safe(req, next, &to_queue, list) {
> __set_bit(FR_PENDING, &req->flags);
> + clear_bit(FR_SENT, &req->flags);
> /* mark the request as resend request */
> req->in.h.unique |= FUSE_UNIQUE_RESEND;
> }
>

ACK, fix looks good.

Would you mind resending it as a proper patch?

Thanks,
Miklos

2024-05-08 09:43:03

by Hou Tao

Subject: Re: WARNING in fuse_request_end

On 5/8/2024 4:21 PM, Miklos Szeredi wrote:
> On Tue, 7 May 2024 at 15:30, Hou Tao <[email protected]> wrote:
>
>> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
>> index 3ec8bb5e68ff5..840cefdf24e26 100644
>> --- a/fs/fuse/dev.c
>> +++ b/fs/fuse/dev.c
>> @@ -1814,6 +1814,7 @@ static void fuse_resend(struct fuse_conn *fc)
>>
>> list_for_each_entry_safe(req, next, &to_queue, list) {
>> __set_bit(FR_PENDING, &req->flags);
>> + clear_bit(FR_SENT, &req->flags);
>> /* mark the request as resend request */
>> req->in.h.unique |= FUSE_UNIQUE_RESEND;
>> }
>>
> ACK, fix looks good.
>
> Would you mind resending it as a proper patch?

Thanks for the ACK. Will post it.
>
> Thanks,
> Miklos
>
> .