syzbot


KASAN: use-after-free Read in end_requests

Status: auto-closed as invalid on 2019/02/22 10:34
Reported-by: syzbot+444b9c373e79de86c456@syzkaller.appspotmail.com
First crash: 1685d, last: 1685d

Sample crash report:
bridge0: port 3(veth0) entered disabled state
device veth0 entered promiscuous mode
bridge0: port 3(veth0) entered blocking state
bridge0: port 3(veth0) entered forwarding state
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0xd0/0xf3 lib/list_debug.c:42
Read of size 8 at addr ffff8801d89e4a08 by task syz-executor6/7918

CPU: 1 PID: 7918 Comm: syz-executor6 Not tainted 4.18.0+ #186
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __list_del_entry_valid+0xd0/0xf3 lib/list_debug.c:42
 __list_del_entry include/linux/list.h:117 [inline]
 list_del_init include/linux/list.h:159 [inline]
 end_requests+0x180/0x460 fs/fuse/dev.c:2044
 fuse_dev_release+0x18c/0x2e0 fs/fuse/dev.c:2154
 __fput+0x355/0x8b0 fs/file_table.c:209
 ____fput+0x15/0x20 fs/file_table.c:243
 task_work_run+0x1ec/0x2a0 kernel/task_work.c:113
 get_signal+0x1559/0x1970 kernel/signal.c:2298
Unknown ioctl 1074021777
 do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x2e0/0x370 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007f7cdc2b5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: 0000000000000030 RBX: 00007f7cdc2b66d4 RCX: 0000000000457089
RDX: 0000000000001000 RSI: 0000000020001000 RDI: 0000000000000003
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d3240 R14: 00000000004c8281 R15: 0000000000000001

Allocated by task 7914:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
 __fuse_request_alloc+0x27/0xf0 fs/fuse/dev.c:58
 fuse_request_alloc+0x18/0x20 fs/fuse/dev.c:89
 fuse_fill_super+0x12cb/0x1ee0 fs/fuse/inode.c:1154
 mount_nodev+0x6b/0x110 fs/super.c:1220
 fuse_mount+0x2c/0x40 fs/fuse/inode.c:1210
 mount_fs+0xae/0x328 fs/super.c:1277
 vfs_kern_mount.part.34+0xdc/0x4e0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2542 [inline]
 do_mount+0x581/0x30e0 fs/namespace.c:2872
 ksys_mount+0x12d/0x140 fs/namespace.c:3088
 __do_sys_mount fs/namespace.c:3102 [inline]
 __se_sys_mount fs/namespace.c:3099 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3099
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 7914:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
 fuse_request_free+0x8b/0xa0 fs/fuse/dev.c:104
 fuse_put_request+0x2b7/0x360 fs/fuse/dev.c:294
 request_end+0x3ee/0xb20 fs/fuse/dev.c:403
 end_requests+0x296/0x460 fs/fuse/dev.c:2045
 fuse_abort_conn+0xf9c/0x1580 fs/fuse/dev.c:2138
 fuse_put_super+0x123/0x440 fs/fuse/inode.c:396
 generic_shutdown_super+0x1bf/0x530 fs/super.c:453
 kill_anon_super+0x3c/0x50 fs/super.c:1046
 fuse_kill_sb_anon+0x90/0xb0 fs/fuse/inode.c:1223
 deactivate_locked_super+0x97/0x100 fs/super.c:326
 deactivate_super+0x193/0x1c0 fs/super.c:357
 cleanup_mnt+0xbf/0x160 fs/namespace.c:1183
 __cleanup_mnt+0x16/0x20 fs/namespace.c:1190
 task_work_run+0x1ec/0x2a0 kernel/task_work.c:113
 get_signal+0x1559/0x1970 kernel/signal.c:2298
 do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x2e0/0x370 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801d89e4a00
 which belongs to the cache fuse_request of size 448
The buggy address is located 8 bytes inside of
 448-byte region [ffff8801d89e4a00, ffff8801d89e4bc0)
The buggy address belongs to the page:
page:ffffea0007627900 count:1 mapcount:0 mapping:ffff8801d478cb40 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0006c23bc8 ffff8801d4749348 ffff8801d478cb40
raw: 0000000000000000 ffff8801d89e4000 0000000100000008 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d89e4900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801d89e4980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801d89e4a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff8801d89e4a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d89e4b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci-upstream-kasan-gce-root 2018/08/13 14:08 upstream 94710cac0ef4 7a88b141 .config console log report
* Struck through repros no longer work on HEAD.