| // KASAN: use-after-free Read in blkdev_get |
| // https://syzkaller.appspot.com/bug?id=00965426fe7ceec1fd2d8756770d4c7c3cacdc4b |
| // status:open |
| // autogenerated by syzkaller (http://github.com/google/syzkaller) |
| |
| #define _GNU_SOURCE |
| #include <endian.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <linux/loop.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <sys/ioctl.h> |
| #include <sys/mount.h> |
| #include <sys/stat.h> |
| #include <sys/syscall.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| extern unsigned long long procid; |
| |
| struct fs_image_segment { |
| void* data; |
| uintptr_t size; |
| uintptr_t offset; |
| }; |
| |
| #define IMAGE_MAX_SEGMENTS 4096 |
| #define IMAGE_MAX_SIZE (129 << 20) |
| |
| #define SYZ_memfd_create 319 |
| |
| static uintptr_t syz_mount_image(uintptr_t fsarg, uintptr_t dir, uintptr_t size, |
| uintptr_t nsegs, uintptr_t segments, |
| uintptr_t flags, uintptr_t optsarg) |
| { |
| char loopname[64], fs[32], opts[256]; |
| int loopfd, err = 0, res = -1; |
| uintptr_t i; |
| struct fs_image_segment* segs = (struct fs_image_segment*)segments; |
| |
| if (nsegs > IMAGE_MAX_SEGMENTS) |
| nsegs = IMAGE_MAX_SEGMENTS; |
| for (i = 0; i < nsegs; i++) { |
| if (segs[i].size > IMAGE_MAX_SIZE) |
| segs[i].size = IMAGE_MAX_SIZE; |
| segs[i].offset %= IMAGE_MAX_SIZE; |
| if (segs[i].offset > IMAGE_MAX_SIZE - segs[i].size) |
| segs[i].offset = IMAGE_MAX_SIZE - segs[i].size; |
| if (size < segs[i].offset + segs[i].offset) |
| size = segs[i].offset + segs[i].offset; |
| } |
| if (size > IMAGE_MAX_SIZE) |
| size = IMAGE_MAX_SIZE; |
| int memfd = syscall(SYZ_memfd_create, "syz_mount_image", 0); |
| if (memfd == -1) { |
| err = errno; |
| goto error; |
| } |
| if (ftruncate(memfd, size)) { |
| err = errno; |
| goto error_close_memfd; |
| } |
| for (i = 0; i < nsegs; i++) { |
| if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 0) { |
| } |
| } |
| snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid); |
| 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; |
| } |
| } |
| mkdir((char*)dir, 0777); |
| memset(fs, 0, sizeof(fs)); |
| strncpy(fs, (char*)fsarg, sizeof(fs) - 1); |
| memset(opts, 0, sizeof(opts)); |
| strncpy(opts, (char*)optsarg, sizeof(opts) - 32); |
| if (strcmp(fs, "iso9660") == 0) { |
| flags |= MS_RDONLY; |
| } else if (strncmp(fs, "ext", 3) == 0) { |
| if (strstr(opts, "errors=panic") || strstr(opts, "errors=remount-ro") == 0) |
| strcat(opts, ",errors=continue"); |
| } else if (strcmp(fs, "xfs") == 0) { |
| strcat(opts, ",nouuid"); |
| } |
| if (mount(loopname, (char*)dir, fs, flags, opts)) { |
| err = errno; |
| goto error_clear_loop; |
| } |
| res = 0; |
| error_clear_loop: |
| ioctl(loopfd, LOOP_CLR_FD, 0); |
| error_close_loop: |
| close(loopfd); |
| error_close_memfd: |
| close(memfd); |
| error: |
| errno = err; |
| return res; |
| } |
| |
| static void execute_one(); |
| extern unsigned long long procid; |
| |
| void loop() |
| { |
| while (1) { |
| execute_one(); |
| } |
| } |
| |
| unsigned long long procid; |
| void execute_one() |
| { |
| memcpy((void*)0x20000000, "reiserfs", 9); |
| memcpy((void*)0x20000100, "./fiue0", 8); |
| *(uint64_t*)0x20000200 = 0x20000240; |
| memcpy((void*)0x20000240, |
| "\x00\x08\x00\x00\xec\x05\x00\x00\x6d\x8a\x2b\x00\x12\x00\x00\x00\x08" |
| "\x08\x00\x00\xb9\x02\x00\x00\x00\x01\x00\x00\x84\x81\x1f\x4c\xe1\x00" |
| "\x00\x00\x1e\x00\x00\x00\x00\x00\x00\x00\x00\x10\xec\x03\x02\xe5\xfb" |
| "\x00\x52\x65\x49\x73\x45\x72\x33\x46\x73", |
| 61); |
| *(uint64_t*)0x20000208 = 0x3d; |
| *(uint64_t*)0x20000210 = 0x10000; |
| *(uint8_t*)0x20013900 = 0; |
| syz_mount_image(0x20000000, 0x20000100, 0x400000000000000, 1, 0x20000200, 0, |
| 0x20013900); |
| } |
| |
| int main() |
| { |
| syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); |
| for (procid = 0; procid < 8; procid++) { |
| if (fork() == 0) { |
| for (;;) { |
| loop(); |
| } |
| } |
| } |
| sleep(1000000); |
| return 0; |
| } |