Hi, We would like to report the following bug which has been found by our modified version of syzkaller. ====================================================== description: KASAN: use-after-free Read in reiserfs_fill_super affected file: fs/reiserfs/inode.c kernel version: 5.19-rc6 kernel commit: 32346491ddf24599decca06190ebca03ff9de7f8 git tree: upstream kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=cd73026ceaed1402 crash reproducer: attached ====================================================== Crash log: ====================================================== UG: KASAN: use-after-free in init_inode fs/reiserfs/inode.c:1325 [inline] BUG: KASAN: use-after-free in reiserfs_read_locked_inode+0x1f9c/0x2300 fs/reiserfs/inode.c:1574 Read of size 4 at addr ffff88819f38c000 by task syz-executor.5/13593 CPU: 0 PID: 13593 Comm: syz-executor.5 Tainted: G OE 5.19.0-rc6-g2eae0556bb9d #2 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+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:313 [inline] print_report.cold+0xe5/0x659 mm/kasan/report.c:429 kasan_report+0x8a/0x1b0 mm/kasan/report.c:491 init_inode fs/reiserfs/inode.c:1325 [inline] reiserfs_read_locked_inode+0x1f9c/0x2300 fs/reiserfs/inode.c:1574 reiserfs_fill_super+0x126c/0x2f10 fs/reiserfs/super.c:2073 mount_bdev+0x34d/0x410 fs/super.c:1367 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1497 do_new_mount fs/namespace.c:3040 [inline] path_mount+0x1228/0x1cb0 fs/namespace.c:3370 do_mount+0xf3/0x110 fs/namespace.c:3383 __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f4fe2e8fe8e Code: 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4fe148b9f8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f4fe2e8fe8e RDX: 0000000020000040 RSI: 0000000020000100 RDI: 00007f4fe148ba50 RBP: 00007f4fe148ba90 R08: 00007f4fe148ba90 R09: 0000000020000040 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000040 R13: 0000000020000100 R14: 00007f4fe148ba50 R15: 0000000020011400 </TASK> The buggy address belongs to the physical page: page:ffffea00067ce300 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x1 pfn:0x19f38c flags: 0x17ff00000000000(node=0|zone=2|lastcpupid=0x7ff) raw: 017ff00000000000 ffffea000610d9c8 ffffea0006897b08 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffff7f 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 2972, tgid 2972 (systemd-udevd), ts 583268397100, free_ts 649857437696 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2449 [inline] prep_new_page+0x297/0x330 mm/page_alloc.c:2456 get_page_from_freelist+0x2142/0x3c80 mm/page_alloc.c:4198 __alloc_pages+0x321/0x710 mm/page_alloc.c:5426 __folio_alloc+0x12/0x40 mm/page_alloc.c:5457 vma_alloc_folio+0xf9/0x6e0 mm/mempolicy.c:2233 alloc_page_vma include/linux/gfp.h:634 [inline] wp_page_copy+0x1f1/0x1d00 mm/memory.c:3104 do_wp_page+0x52c/0x1840 mm/memory.c:3471 handle_pte_fault mm/memory.c:4921 [inline] __handle_mm_fault+0x2a69/0x3ee0 mm/memory.c:5042 handle_mm_fault+0x322/0xa80 mm/memory.c:5140 do_user_addr_fault+0x489/0x11c0 arch/x86/mm/fault.c:1397 handle_page_fault arch/x86/mm/fault.c:1484 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1540 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:570 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1371 [inline] free_pcp_prepare+0x51f/0xd00 mm/page_alloc.c:1421 free_unref_page_prepare mm/page_alloc.c:3343 [inline] free_unref_page_list+0x15a/0xe90 mm/page_alloc.c:3475 release_pages+0x10ea/0x2590 mm/swap.c:980 tlb_batch_pages_flush mm/mmu_gather.c:58 [inline] tlb_flush_mmu_free mm/mmu_gather.c:255 [inline] tlb_flush_mmu+0xef/0x690 mm/mmu_gather.c:262 tlb_finish_mmu+0x93/0x3c0 mm/mmu_gather.c:353 exit_mmap+0x1de/0x4b0 mm/mmap.c:3164 __mmput kernel/fork.c:1196 [inline] mmput+0x16b/0x430 kernel/fork.c:1217 exit_mm kernel/exit.c:511 [inline] do_exit+0xa33/0x2dd0 kernel/exit.c:784 do_group_exit+0xd2/0x2f0 kernel/exit.c:927 __do_sys_exit_group kernel/exit.c:938 [inline] __se_sys_exit_group kernel/exit.c:936 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:936 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Memory state around the buggy address: ffff88819f38bf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88819f38bf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88819f38c000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88819f38c080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88819f38c100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== -- Thanks and Regards, Dipanjan
Attachment:
repro.syz
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 <stddef.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/ioctl.h> #include <sys/mount.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> #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 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 fs_image_segment { void* data; uintptr_t size; uintptr_t offset; }; #define IMAGE_MAX_SEGMENTS 4096 #define IMAGE_MAX_SIZE (129 << 20) static unsigned long fs_image_segment_check(unsigned long size, unsigned long nsegs, struct fs_image_segment* segs) { if (nsegs > IMAGE_MAX_SEGMENTS) nsegs = IMAGE_MAX_SEGMENTS; for (size_t 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; return size; } static int setup_loop_device(long unsigned size, long unsigned nsegs, struct fs_image_segment* segs, const char* loopname, int* memfd_p, int* loopfd_p) { int err = 0, loopfd = -1; size = fs_image_segment_check(size, nsegs, segs); int memfd = syscall(__NR_memfd_create, "syzkaller", 0); if (memfd == -1) { err = errno; goto error; } if (ftruncate(memfd, size)) { err = errno; goto error_close_memfd; } for (size_t i = 0; i < nsegs; i++) { if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 0) { } } 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; } } *memfd_p = 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 unsigned long size, volatile unsigned long nsegs, volatile long segments, volatile long flags, volatile long optsarg) { struct fs_image_segment* segs = (struct fs_image_segment*)segments; int res = -1, err = 0, loopfd = -1, memfd = -1, need_loop_device = !!segs; 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(size, nsegs, segs, loopname, &memfd, &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) { if (strstr(opts, "errors=panic") || strstr(opts, "errors=remount-ro") == 0) 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; } error_clear_loop: if (need_loop_device) { ioctl(loopfd, LOOP_CLR_FD, 0); close(loopfd); close(memfd); } errno = err; return res; } 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"); } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; iter++) { reset_loop(); 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; } } } void execute_one(void) { memcpy((void*)0x20000040, "reiserfs\000", 9); memcpy((void*)0x20000100, "./file0\000", 8); *(uint64_t*)0x20000200 = 0x20010000; memcpy((void*)0x20010000, "\x00\x40\x00\x00\x68\x02\x00\x00\x97\x3d\x00\x00\x12\x00\x00\x00\x00\x00\x00\x00\x84\x3d\x00\x00\x00\x01\x00\x00\x61\x1c\xad\x49\xe1\x00\x00\x00\x1e\x00\x00\x00\x00\x00\x00\x00\x00\x10\xec\x03\x02\x00\x01\x00\x52\x65\x49\x73\x45\x72\x33\x46\x73\x00\x00\x00\x02\x00\x00\x00\x02", 69); *(uint64_t*)0x20000208 = 0x45; *(uint64_t*)0x20000210 = 0x10000; *(uint64_t*)0x20000218 = 0x20011100; memcpy((void*)0x20011100, "\x80\x00\x00\x03\x00\x20\x00\x00\x00\x00\x00\x00\x12\x00\x00\x00\x00\x00\x00\x00\x84\x3d\x00\x00\x00\x01\x00\x00\x61\x1c\xad\x49\xe1", 33); *(uint64_t*)0x20000220 = 0x21; *(uint64_t*)0x20000228 = 0x3d96000; *(uint64_t*)0x20000230 = 0x20000280; memcpy((void*)0x20000280, "\x01\x00\x02\x00\x75\x0f\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x20\x00\xe0\x0f\x10\x00\x01\x00\x00\x00\x02\x00\x00\x00\x01\x00\x00\x00\xf4\x01\x00\x00\x02\x00\x23\x00\xbd\x0f\xf9\x0b\x71\x85\xf1\x1a\xc8\x09\x10\x8c\x77\x8d\x51\xe3\xe0\x43\xcb\x42\x20\x23\x61\x74\xc7\x8c\x42\xb1\x79\x5b\x37\x3c\xcf\x55\x37\xfa\x6c\x8b\x4c\x1b\xab\xd7\xf1\xcc\xf3\x48\x07\x55\x75\x1b\xc5\x30\xc9\xa7\xfb\x72\x41\xbd\x73\xcc\x02\x82\xae\x33\xdc\x1e\x8d\x35\xe3\xb3\x0f\x5b\xff\xf3\x3e\x0c\x10\xbd\xc3\x34\x11\x6f\xb3\x19\x36\x26\x6d\x74\x93\x69\xef\x5f\x46\x28\x66\x32\xae\xdd\xa8\x68\x21\x79\xd4\xd2\x90\x00\x00\x00\x00\x8d\xbd\x44\xdd\xc4\xa1\xc7\x5a\xb7\x9b\x5b\x94\xd6\x5c\xd1\x95\x88\x55\x40\xd1\xc0\x3d\x68\x40\x23\x2d\xdd\xa8\x3d\xd6\x70\xb6\x37\x78\x74\xd0\xf1\x51\xa2\x1b\x68\x27\x77\x9b\xf7\xb1\x0f\xf8\x60\x7a\x65\x83\x77\xd9\x00\x00\x0c\xcb\xba\xa7\xc5\xe7\x1b\xf2\x1d\x89\xe1\xe2\x46\xec\x1c\x98\x96\x67\x26\x04\x0b\x31\xac\x7f\x54\xc9\x7a\x67\x1b\x53\xf9\x99\x0d\xac\x11\xf0\x79\xbd\xa4\xdb\x57\xc9\x3f\xa1\x01\xd9\xd5\x33\x17\x40\xef\x9b\x9d\x69\xc3\x28\xa0\xea\xdf\x29\xc8\xc6\x3d\xe2\x48\xc7\x95\x93\x28\x15\x0f\x17\xb9\xcf\x72", 308); *(uint64_t*)0x20000238 = 0x134; *(uint64_t*)0x20000240 = 0x3d97000; *(uint8_t*)0x20011400 = 0; syz_mount_image(0x20000040, 0x20000100, 0, 3, 0x20000200, 0, 0x20011400); } int main(void) { syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); loop(); return 0; }
