Messages in this thread | | | From | Weiß, Simone <> | Subject | BUG: MAX_LOCKDEP_ENTRIES too low! triggered by ext4&workqueue | Date | Wed, 13 Mar 2024 12:15:24 +0000 |
| |
Dear all,
For some experimentation, I have been running fuzzing campaigns and I noticed BUG: MAX_LOCKDEP_ENTRIES too low! most likely triggered by ext4 operations.
As I found a C reproducer in my setup, it could be bisected being introduced with the following: commit 967b494e2fd143a9c1a3201422aceadb5fa9fbfc Author: Tejun Heo <tj@kernel.org> Date: Mon Aug 7 15:57:23 2023 -1000
workqueue: Use a kthread_worker to release pool_workqueues pool_workqueue release path is currently bounced to system_wq; however, this is a bit tricky because this bouncing occurs while holding a pool lock and thus has risk of causing a A-A deadlock. This is currently addressed by the fact that only unbound workqueues use this bouncing path and system_wq is a per-cpu workqueue. ...
It was reproducible on v6.6.16 and v6.16.21. The C reproducer is automatically generated by syzkaller and included below.
If you need any further information, just let me know.
Best, Simone
Sample Crash ------------ BUG: MAX_LOCKDEP_ENTRIES too low! turning off the locking correctness validator. CPU: 0 PID: 1011 Comm: syz-executor232 Not tainted 6.6.16-eb-corbos-standard- syzkaller-geb3e299184cc #0 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x128/0x214 arch/arm64/kernel/stacktrace.c:233 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xac/0x128 lib/dump_stack.c:106 dump_stack+0x20/0x2c lib/dump_stack.c:113 alloc_list_entry kernel/locking/lockdep.c:1397 [inline] add_lock_to_list+0x24c/0x2d8 kernel/locking/lockdep.c:1418 check_prev_add kernel/locking/lockdep.c:3204 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x35dc/0x6344 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x47c/0x770 kernel/locking/lockdep.c:5719 _raw_spin_lock_nested+0x50/0x6c kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested kernel/sched/core.c:558 [inline] raw_spin_rq_lock kernel/sched/sched.h:1372 [inline] rq_lock kernel/sched/sched.h:1681 [inline] __schedule+0x218/0x2448 kernel/sched/core.c:6614 preempt_schedule_irq+0x80/0x1ac kernel/sched/core.c:7008 arm64_preempt_schedule_irq+0x3c/0x54 arch/arm64/kernel/entry-common.c:267 __el1_irq arch/arm64/kernel/entry-common.c:505 [inline] el1_interrupt+0x3c/0x54 arch/arm64/kernel/entry-common.c:517 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:522 el1h_64_irq+0x68/0x6c arch/arm64/kernel/entry.S:595 __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:182 [inline] arch_local_irq_restore arch/arm64/include/asm/irqflags.h:202 [inline] lock_acquire kernel/locking/lockdep.c:5757 [inline] lock_acquire+0x4c4/0x770 kernel/locking/lockdep.c:5719 __flush_workqueue+0x124/0xf28 kernel/workqueue.c:3140 drain_workqueue+0x184/0x36c kernel/workqueue.c:3305 destroy_workqueue+0xb4/0x9a0 kernel/workqueue.c:4800 ext4_put_super+0xe0/0x924 fs/ext4/super.c:1311 generic_shutdown_super+0x120/0x324 fs/super.c:693 kill_block_super+0x3c/0x74 fs/super.c:1646 ext4_kill_sb+0x60/0xb8 fs/ext4/super.c:7320 deactivate_locked_super+0xa0/0x1a8 fs/super.c:481 deactivate_super fs/super.c:514 [inline] deactivate_super+0x118/0x148 fs/super.c:510 cleanup_mnt+0x1b8/0x338 fs/namespace.c:1254 __cleanup_mnt+0x20/0x30 fs/namespace.c:1261 task_work_run+0x148/0x254 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0xe04/0x18f4 arch/arm64/kernel/signal.c:1305 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:144 [inline] el0_svc+0x11c/0x140 arch/arm64/kernel/entry-common.c:679 el0t_64_sync_handler+0x100/0x12c arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x194/0x198 arch/arm64/kernel/entry.S:599
Reproducer ---------- // https://None.appspot.com/bug?id=422a59d59663a31fd6b1d700eab33c89c33a029b // autogenerated by syzkaller (https://github.com/google/syzkaller)
#define _GNU_SOURCE
#include <dirent.h> #include <endian.h> #include <errno.h> #include <fcntl.h> #include <sched.h> #include <setjmp.h> #include <signal.h> #include <stdarg.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/prctl.h> #include <sys/resource.h> #include <sys/stat.h> #include <sys/syscall.h> #include <sys/time.h> #include <sys/types.h> #include <sys/wait.h> #include <time.h> #include <unistd.h>
#include <linux/capability.h> #include <linux/loop.h>
#ifndef __NR_memfd_create #define __NR_memfd_create 279 #endif #ifndef __NR_mmap #define __NR_mmap 222 #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 use_temporary_dir(void) { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) exit(1); if (chmod(tmpdir, 0777)) exit(1); if (chdir(tmpdir)) exit(1); }
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; }
#define MAX_FDS 30
//% 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 madler@alumni.caltech.edu
//% 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; }
static void setup_common() { if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) { } }
static void setup_binderfs() { if (mkdir("/dev/binderfs", 0777)) { } if (mount("binder", "/dev/binderfs", "binder", 0, NULL)) { } }
static void loop();
static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = (200 << 20); setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 32 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 136 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 128 << 20; setrlimit(RLIMIT_CORE, &rlim); rlim.rlim_cur = rlim.rlim_max = 256; setrlimit(RLIMIT_NOFILE, &rlim); if (unshare(CLONE_NEWNS)) { } if (mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } typedef struct { const char* name; const char* value; } sysctl_t; static const sysctl_t sysctls[] = { {"/proc/sys/kernel/shmmax", "16777216"}, {"/proc/sys/kernel/shmall", "536870912"}, {"/proc/sys/kernel/shmmni", "1024"}, {"/proc/sys/kernel/msgmax", "8192"}, {"/proc/sys/kernel/msgmni", "1024"}, {"/proc/sys/kernel/msgmnb", "1024"}, {"/proc/sys/kernel/sem", "1024 1048576 500 1024"}, }; unsigned i; for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++) write_file(sysctls[i].name, sysctls[i].value); }
static int wait_for_loop(int pid) { if (pid < 0) exit(1); int status = 0; while (waitpid(-1, &status, __WALL) != pid) { } return WEXITSTATUS(status); }
static void drop_caps(void) { struct __user_cap_header_struct cap_hdr = {}; struct __user_cap_data_struct cap_data[2] = {}; cap_hdr.version = _LINUX_CAPABILITY_VERSION_3; cap_hdr.pid = getpid(); if (syscall(SYS_capget, &cap_hdr, &cap_data)) exit(1); const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE); cap_data[0].effective &= ~drop; cap_data[0].permitted &= ~drop; cap_data[0].inheritable &= ~drop; if (syscall(SYS_capset, &cap_hdr, &cap_data)) exit(1); }
static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid != 0) return wait_for_loop(pid); setup_common(); sandbox_common(); drop_caps(); if (unshare(CLONE_NEWNET)) { } write_file("/proc/sys/net/ipv4/ping_group_range", "0 65535"); setup_binderfs(); loop(); exit(1); }
#define FS_IOC_SETFLAGS _IOW('f', 2, long) static void remove_dir(const char* dir) { int iter = 0; DIR* dp = 0; retry: while (umount2(dir, MNT_DETACH | UMOUNT_NOFOLLOW) == 0) { } dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exit(1); } exit(1); } struct dirent* ep = 0; while ((ep = readdir(dp))) { if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue; char filename[FILENAME_MAX]; snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); while (umount2(filename, MNT_DETACH | UMOUNT_NOFOLLOW) == 0) { } struct stat st; if (lstat(filename, &st)) exit(1); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EPERM) { int fd = open(filename, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) { } close(fd); continue; } } if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exit(1); if (umount2(filename, MNT_DETACH | UMOUNT_NOFOLLOW)) exit(1); } } closedir(dp); for (int i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EPERM) { int fd = open(dir, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) { } close(fd); continue; } } if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, MNT_DETACH | UMOUNT_NOFOLLOW)) exit(1); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exit(1); } }
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 reset_loop() { char buf[64]; snprintf(buf, sizeof(buf), "/dev/loop%llu", procid); int loopfd = open(buf, O_RDWR); if (loopfd != -1) { ioctl(loopfd, LOOP_CLR_FD, 0); close(loopfd); } }
static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); if (symlink("/dev/binderfs", "./binderfs")) { } }
static void close_fds() { for (int fd = 3; fd < MAX_FDS; fd++) close(fd); }
static void execute_one(void);
#define WAIT_FLAGS __WALL
static void loop(void) { int iter = 0; for (;; iter++) { char cwdbuf[32]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) exit(1); reset_loop(); int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { if (chdir(cwdbuf)) exit(1); setup_test(); execute_one(); close_fds(); 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; } remove_dir(cwdbuf); } }
void execute_one(void) { memcpy((void*)0x20000540, "ext4\000", 5); memcpy((void*)0x20000580, "./file0\000", 8); memcpy((void*)0x20000000, "\x00\xf7\xf3\x9e\xf9\xcd\x1c\x6a\x04\x3f\xd7\x8a\xa7\xf9\xce\xb4\xe5" "\xc2\xc4\x3d\xa9\xd7\x96\x18\xdd\x18\xc1\x68\x98\x9c\x2d\xc4\xb4\x12" "\xca\x72\x6b\x49\x63\x9a\x98\x2c\xdf\x09\x41\x2c\x67\xd4\x7a\xc4\x0b" "\xa2\x43\x93\x7f\x7d\xe1\xf5\x33\xf3\xfa\xf1\xb1\xc0\x6d\x75\xa8\x9a" "\x1a\xfa\x46\x79\x71\xac\x77\x27\x84\x46\x28\x3e\xf9\x0c\xba\xcd\x7d" "\x21\x9b\x47\x63\x46\xfd\x12\x2c\xed\xa1\x50\x65\xe1\xa1\xb1\xdf\xee" "\x4f\x0a\x1c\x59\xac\x58\xc8\x1e\xe7\x58\x34\x10\x8b\x6b\xb2\x06", 118); memcpy( (void*)0x200005c0, "\x78\x9c\xec\xdd\xcf\x6b\x1c\x55\x1c\x00\xf0\xef\x6c\x92\x36\xb6\x6a\x5b" "\x28\x45\x3d\x68\xa0\xa0\x85\xda\x4d\x93\xf8\xa3\x82\x87\xf6\x28\x5a\x2c" "\xe8\xcd\x43\xbb\x24\xdb\x50\xb2\xe9\x96\xec\xa6\x34\x69\xc1\xf6\x60\x2f" "\x5e\xa4\x08\x22\x16\x44\xf0\xea\xdd\x63\xf1\x1f\xf0\xe0\x1f\xe0\xa9\xa0" "\x85\x22\x25\x78\xf1\xe0\xca\x6c\x66\xd3\x6d\xb2\x9b\xac\x49\xb6\xbb\x74" "\x3f\x1f\x98\xe6\xbd\x99\xd9\x7d\xef\x3b\xf3\xde\xdb\x37\x3b\x53\x36\x80" "\x81\x35\x96\xfe\x93\x8b\x78\x39\x22\xbe\x4a\x22\x0e\x34\x6d\x1b\x8e\x6c" "\xe3\xd8\xea\x7e\x2b\x8f\x6e\x4c\xa7\x4b\x12\xb5\xda\x27\x7f\x25\x91\x64" "\xeb\x1a\xfb\x27\xd9\xdf\xfd\x59\xe6\xa5\x88\xf8\xe5\x8b\x88\xe3\xb9\x8d" "\xe5\x56\x96\x96\xe7\x0a\xa5\x52\x71\x21\xcb\x8f\x57\xe7\xaf\x8c\x57\x96" "\x96\x4f\x5c\x9a\x2f\xcc\x16\x67\x8b\x97\x27\xa7\xa6\x4e\xbd\x3d\x35\xf9" "\xde\xbb\xef\xec\x46\x98\xd7\x0f\xad\xfe\xfd\xf6\xe3\x7b\x1f\x9c\xfa\xf2" "\xe8\xca\x37\x3f\x3d\x38\x74\x27\x89\xd3\xf1\x6f\xad\x56\x8b\x75\x71\xec" "\x96\xb1\x18\xcb\x8e\xc9\x48\x9c\x5e\xb7\x6d\x62\xb7\x0b\xeb\xb1\xa4\xd7" "\x15\x60\x5b\x86\xb2\x7e\x3e\x12\xe9\x18\x70\x20\x86\xb2\x5e\x0f\x3c\xfb" "\x3e\x8f\x88\x1a\x30\xa0\x12\xfd\x1f\x06\x54\x63\x1e\xd0\xb8\xb6\xef\xc6" "\x75\x70\x3f\x7b\x78\x26\xe2\xb3\x5c\xab\xf8\x87\x57\xbf\x1b\x89\xd1\xfa" "\xb5\xd1\xbe\x95\xe4\x89\x2b\xa3\xf4\x7a\xf7\xe0\x2e\x94\x3f\x1a\x11\x3f" "\xff\x79\xf7\x4e\xba\x44\x97\xbe\x87\x00\x68\xe5\xe6\xad\x88\x38\x39\x3c" "\xbc\x71\xfc\x4b\xb2\xf1\x6f\xfb\x4e\x76\xb0\xcf\xfa\x32\x8c\x7f\xf0\xf4" "\xdc\x3b\x13\x11\x6f\xb6\x9a\xff\xe4\xd6\xe6\x3f\x91\xcd\x7f\x9a\xe7\x8b" "\xfb\x5b\xf4\xdd\xed\xd8\xba\xff\xe7\x1e\xec\x42\x31\x6d\xa5\xf3\xbf\xf7" "\x5b\xce\x7f\xd7\x6e\x5a\x1d\x1c\xca\x72\x2f\xd4\xe7\x7c\x23\xc9\xc5\x4b" "\xa5\x62\x3a\xb6\xbd\x18\x11\xc7\x62\x64\x6f\x9a\xdf\xec\x7e\xce\xa9\x95" "\xfb\xb5\x76\xdb\xc6\x9a\xe6\x7f\xe9\x92\x96\xdf\x98\x0b\x66\xf5\x78\x30" "\xbc\xf7\xc9\xd7\xcc\x14\xaa\x85\x9d\xc4\xdc\xec\xe1\xad\x88\x57\x86\x5b" "\xc5\x9f\xac\x9d\xff\xa4\xc5\xfc\x37\x3d\x1e\xe7\x3a\x2c\xe3\x48\xf1\xee" "\xab\xed\xb6\x6d\x1d\xff\x66\x7e\xef\xb0\x06\xed\xd5\x7e\x88\x78\xa3\xf9" "\xfc\xff\xd6\xd8\xf2\xf8\x8e\x56\xb2\xf9\xfd\xc9\xf1\x7a\x7b\x18\x6f\xb4" "\x8a\x8d\xfe\xbe\x7d\xe4\xd7\x76\xe5\xef\x2c\xfe\x9d\x4b\xcf\xff\xbe\x96" "\xed\x7f\x2d\xfe\x83\x49\xf3\xfd\xda\xca\xd6\xef\xf9\xe3\xba\xfc\xf7\xa3" "\xff\x14\xdb\xed\xbb\xdd\xf6\xbf\x27\xf9\xb4\x9e\xde\x93\xad\xbb\x56\xa8" "\x56\x17\x26\xd2\xdc\x47\x1b\xd7\x4f\x3e\x7e\x6d\x23\xbf\xba\xff\x6a\xfc" "\xc7\x8e\xa6\xf1\xbf\xd6\x76\xfc\x6b\xd5\xfe\x4f\x47\xc4\x85\x27\x8f\x53" "\x5b\xb7\x0f\xdf\xbe\xb0\xfd\xf8\xbb\x2b\x8d\x7f\xe6\x7f\x9d\xff\x8e\x13" "\x31\x9a\x25\xee\x7f\x78\xfd\xbb\x76\xe5\x77\x76\xfe\xdf\xaa\xa7\x8e\x65" "\x6b\x3a\x19\xff\x3a\xad\xe9\x4e\x8e\x1d\x00\x00\x00\x00\x00\x00\xf4\x9b" "\x5c\x44\x3c\x1f\x49\x2e\xbf\x96\xce\xe5\xf2\xf9\xd5\xe7\x3b\x0e\xc7\xbe" "\x5c\xa9\x5c\xa9\x1e\xbf\x58\x5e\xbc\x3c\x93\x6e\xab\x3f\xff\x90\x6b\xdc" "\xe9\x3e\xd0\xf4\x3c\xc4\x44\xf6\x3c\x6c\x23\x3f\xb9\x2e\x3f\x15\x11\x87" "\x22\xe2\xeb\xa1\xe7\xea\xf9\xfc\x74\xb9\x34\xd3\xeb\xe0\x01\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xa0\x4f\xec\x6f\xf3\xff\xff" "\x53\x7f\x0c\xf5\xba\x76\x40\xd7\xf9\xc9\x6f\x18\x5c\x8f\xfb\xff\x48\x4f" "\xeb\x01\x3c\x7d\x3e\xff\x61\x70\xe9\xff\x30\xb8\xf4\x7f\x18\x5c\xfa\x3f" "\x0c\x2e\xfd\x1f\x06\xd7\x36\xfa\xff\xeb\xdd\xa8\x07\xf0\xf4\xf9\xfc\x87" "\xc1\xb5\xae\xff\x8f\x6e\xba\x73\xd2\xdd\xba\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xc0\x33\xe0\xdc" "\xd9\xb3\xe9\x52\x5b\x79\x74\x63\x3a\xcd\xcf\x5c\x5d\x5a\x9c\x2b\x5f\x3d" "\x31\x53\xac\xcc\xe5\xe7\x17\xa7\xf3\xd3\xe5\x85\x2b\xf9\xd9\x72\x79\xb6" "\x54\xcc\x4f\x97\xe7\xb7\x7a\xbf\x52\xb9\x7c\x65\x62\x32\x16\xaf\x8d\x57" "\x8b\x95\xea\x78\x65\x69\xf9\xfc\x7c\x79\xf1\x72\xf5\xfc\xa5\xf9\xc2\x6c" "\xf1\x7c\xd1\x0f\x0c\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\xc0\x46\x95\xa5\xe5\xb9\x42\xa9\x54\x5c\x18\xc4\x44\x12\x71\x73" "\x93\x7d\xf6\x66\xc7\xa8\x1f\xaa\xda\x85\x44\x12\x49\x3d\xbc\x7e\xa9\x4f" "\xa3\x49\xf6\x4b\x7d\x3a\x49\xa4\x4d\xa4\x0f\xaa\xd1\x8d\x44\xaf\x46\x24" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xd8\xe8\xbf\x00\x00" "\x00\xff\xff\xec\xd9\x32\x7d", 1429); syz_mount_image(/*fs=*/0x20000540, /*dir=*/0x20000580, /*flags=*/0xd, /*opts=*/0x20000000, /*chdir=*/1, /*size=*/0x594, /*img=*/0x200005c0); } 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); for (procid = 0; procid < 6; procid++) { if (fork() == 0) { use_temporary_dir(); do_sandbox_none(); } } sleep(1000000); return 0; }
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