Dear developers and maintainers, We encountered a shift-out-of-bounds bug while using our modified Syzkaller. It is tested against linux kernel 6.9-rc1. Kernel config and C repro are attached to this email. The UBSAN report is listed below. ================================================================================ UBSAN: shift-out-of-bounds in /home/sy/linux-original/drivers/scsi/sg.c:1902:13 shift exponent 64 is too large for 32-bit type 'int' CPU: 1 PID: 8078 Comm: syz-executor748 Not tainted 6.7.0-rc7 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x136/0x150 lib/dump_stack.c:106 ubsan_epilogue lib/ubsan.c:217 [inline] __ubsan_handle_shift_out_of_bounds+0x24b/0x430 lib/ubsan.c:387 sg_build_indirect.cold+0x1b/0x20 drivers/scsi/sg.c:1902 sg_build_reserve+0xc4/0x180 drivers/scsi/sg.c:2012 sg_add_sfp drivers/scsi/sg.c:2194 [inline] sg_open+0xde4/0x1810 drivers/scsi/sg.c:350 chrdev_open+0x269/0x770 fs/char_dev.c:414 do_dentry_open+0x6d3/0x18d0 fs/open.c:948 do_open fs/namei.c:3622 [inline] path_openat+0x1e1e/0x26d0 fs/namei.c:3779 do_filp_open+0x1c9/0x410 fs/namei.c:3809 do_sys_openat2+0x160/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x140/0x1f0 fs/open.c:1463 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f48cf37f80b Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 4c 24 28 64 48 33 0c 25 RSP: 002b:00007ffd29cd7d40 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f48cf37f80b RDX: 0000000000000041 RSI: 00007ffd29cd7dc0 RDI: 00000000ffffff9c RBP: 00007ffd29cd7dc0 R08: 000000000000ffff R09: 00007ffd29cd7c50 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000041 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> ================================================================================ If you have any questions, please contact us. Reported by: Yue Sun <samsun1006219@xxxxxxxxx> Reported by: xingwei lee <xrivendell7@xxxxxxxxx> Best Regards, Yue
Attachment:
config
Description: Binary data
// autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include <dirent.h> #include <endian.h> #include <errno.h> #include <fcntl.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/stat.h> #include <sys/syscall.h> #include <sys/types.h> #include <sys/wait.h> #include <time.h> #include <unistd.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 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 long syz_open_dev(volatile long a0, volatile long a1, volatile long a2) { if (a0 == 0xc || a0 == 0xb) { char buf[128]; sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1, (uint8_t)a2); return open(buf, O_RDWR, 0); } else { char buf[1024]; char* hash; strncpy(buf, (char*)a0, sizeof(buf) - 1); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(a1 % 10); a1 /= 10; } return open(buf, a2, 0); } } 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 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[1] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; memcpy((void*)0x200001c0, "/dev/sg#\000", 9); syz_open_dev(/*dev=*/0x200001c0, /*id=*/0, /*flags=O_CREAT|O_WRONLY*/ 0x41); memcpy((void*)0x20000080, "/sys/module/sg/parameters/scatter_elem_sz\000", 42); res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x20000080ul, /*flags=*/2ul, /*mode=*/0ul); if (res != -1) r[0] = res; sprintf((char*)0x200000c0, "%020llu", (long long)0); *(uint8_t*)0x200000d4 = 0; syscall(__NR_write, /*fd=*/r[0], /*buf=*/0x200000c0ul, /*len=*/0x15ul); } 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; }
