syzbot


KASAN: use-after-free Read in io_uring_cancel_task_requests

Status: auto-closed as invalid on 2022/05/26 09:13
Reported-by: syzbot+a2f389d573cf8c822e06@syzkaller.appspotmail.com
First crash: 762d, last: 762d

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in io_cancel_defer_files fs/io_uring.c:8641 [inline]
BUG: KASAN: use-after-free in io_uring_cancel_task_requests+0x563/0x2c50 fs/io_uring.c:8759
Read of size 8 at addr ffff88814449af08 by task syz-executor.3/21304

CPU: 0 PID: 21304 Comm: syz-executor.3 Not tainted 5.10.102-syzkaller-00166-gcbfab5c59cf6 #0
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_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x8d/0x3d0 mm/kasan/report.c:233
 __kasan_report+0x142/0x220 mm/kasan/report.c:419
 kasan_report+0x51/0x70 mm/kasan/report.c:436
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
 io_cancel_defer_files fs/io_uring.c:8641 [inline]
 io_uring_cancel_task_requests+0x563/0x2c50 fs/io_uring.c:8759
 __io_uring_files_cancel+0x151/0x350 fs/io_uring.c:8845
 io_uring_files_cancel include/linux/io_uring.h:51 [inline]
 do_exit+0x2cc/0x23a0 kernel/exit.c:768
 do_group_exit+0x16a/0x2d0 kernel/exit.c:910
 get_signal+0x131f/0x1f70 kernel/signal.c:2780
 arch_do_signal+0x8d/0x620 arch/x86/kernel/signal.c:805
 exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
 exit_to_user_mode_prepare+0xaa/0xe0 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x24/0x40 kernel/entry/common.c:266
 do_syscall_64+0x3d/0x70 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fde135de059
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fde126d0168 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: 0000000000004000 RBX: 00007fde136f12a0 RCX: 00007fde135de059
RDX: 0000000000000000 RSI: 00000000000051f4 RDI: 0000000000000003
RBP: 00007fde1363808d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeff4a990f R14: 00007fde126d0300 R15: 0000000000022000

Allocated by task 21304:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:428 [inline]
 ____kasan_kmalloc+0xdc/0x110 mm/kasan/common.c:507
 __kasan_kmalloc+0x9/0x10 mm/kasan/common.c:516
 kasan_kmalloc include/linux/kasan.h:269 [inline]
 kmem_cache_alloc_trace+0x210/0x3a0 mm/slub.c:2981
 kmalloc include/linux/slab.h:552 [inline]
 io_req_defer+0x40e/0x11b0 fs/io_uring.c:5923
 io_queue_sqe+0x2a/0x1180 fs/io_uring.c:6399
 io_queue_link_head fs/io_uring.c:6431 [inline]
 io_submit_sqes+0x18d3/0x2da0 fs/io_uring.c:6732
 __do_sys_io_uring_enter fs/io_uring.c:9113 [inline]
 __se_sys_io_uring_enter+0x322/0x12b0 fs/io_uring.c:9055
 __x64_sys_io_uring_enter+0xe5/0x100 fs/io_uring.c:9055
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 21300:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:357
 ____kasan_slab_free+0x133/0x170 mm/kasan/common.c:360
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:368
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:1602 [inline]
 slab_free_freelist_hook+0xcc/0x1a0 mm/slub.c:1628
 slab_free mm/slub.c:3210 [inline]
 kfree+0xd5/0x320 mm/slub.c:4198
 __io_queue_deferred fs/io_uring.c:1541 [inline]
 io_commit_cqring+0x76a/0xa00 fs/io_uring.c:1587
 io_iopoll_complete fs/io_uring.c:2380 [inline]
 io_do_iopoll+0x1e18/0x23f0 fs/io_uring.c:2433
 io_iopoll_try_reap_events+0x116/0x290 fs/io_uring.c:2472
 __io_uring_cancel_task_requests fs/io_uring.c:8715 [inline]
 io_uring_cancel_task_requests+0x26ad/0x2c50 fs/io_uring.c:8763
 io_uring_flush+0x170/0x6d0 fs/io_uring.c:8926
 filp_close+0xb0/0x150 fs/open.c:1319
 close_files fs/file.c:401 [inline]
 put_files_struct+0x1d4/0x350 fs/file.c:429
 exit_files+0x80/0xa0 fs/file.c:458
 do_exit+0x6d9/0x23a0 kernel/exit.c:808
 __do_sys_exit+0x18/0x20 kernel/exit.c:879
 __se_sys_exit+0x14/0x20 kernel/exit.c:877
 __x64_sys_exit+0x3b/0x40 kernel/exit.c:877
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88814449af00
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff88814449af00, ffff88814449af20)
The buggy address belongs to the page:
page:ffffea0005112680 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14449a
flags: 0x8000000000000200(slab)
raw: 8000000000000200 ffffea000420ff00 0000001300000013 ffff888100043980
raw: 0000000000000000 0000000080400040 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 5926, ts 414044536156, free_ts 413985921428
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2385 [inline]
 prep_new_page mm/page_alloc.c:2391 [inline]
 get_page_from_freelist+0xa74/0xa90 mm/page_alloc.c:4063
 __alloc_pages_nodemask+0x3c8/0x820 mm/page_alloc.c:5107
 alloc_slab_page mm/slub.c:1813 [inline]
 allocate_slab+0x6b/0x350 mm/slub.c:1815
 new_slab mm/slub.c:1876 [inline]
 new_slab_objects mm/slub.c:2635 [inline]
 ___slab_alloc+0x143/0x2f0 mm/slub.c:2798
 __slab_alloc mm/slub.c:2838 [inline]
 slab_alloc_node mm/slub.c:2920 [inline]
 slab_alloc mm/slub.c:2962 [inline]
 kmem_cache_alloc_trace+0x278/0x3a0 mm/slub.c:2979
 kmalloc include/linux/slab.h:552 [inline]
 io_req_defer+0x40e/0x11b0 fs/io_uring.c:5923
 io_queue_sqe+0x2a/0x1180 fs/io_uring.c:6399
 io_submit_sqe+0x385/0xfd0 fs/io_uring.c:6489
 io_submit_sqes+0x1050/0x2da0 fs/io_uring.c:6717
 __do_sys_io_uring_enter fs/io_uring.c:9113 [inline]
 __se_sys_io_uring_enter+0x322/0x12b0 fs/io_uring.c:9055
 __x64_sys_io_uring_enter+0xe5/0x100 fs/io_uring.c:9055
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1331 [inline]
 free_pcp_prepare+0x18f/0x1c0 mm/page_alloc.c:1405
 free_unref_page_prepare mm/page_alloc.c:3291 [inline]
 free_unref_page mm/page_alloc.c:3341 [inline]
 free_the_page mm/page_alloc.c:5166 [inline]
 __free_pages+0x2e3/0x4a0 mm/page_alloc.c:5174
 __free_slab+0xdf/0x1a0 mm/slub.c:1901
 free_slab mm/slub.c:1916 [inline]
 discard_slab mm/slub.c:1922 [inline]
 unfreeze_partials+0x17d/0x1b0 mm/slub.c:2416
 put_cpu_partial+0xc8/0x190 mm/slub.c:2452
 __slab_free+0x2eb/0x4e0 mm/slub.c:3102
 do_slab_free mm/slub.c:3198 [inline]
 ___cache_free+0x131/0x150 mm/slub.c:3217
 qlink_free+0x38/0x40 mm/kasan/quarantine.c:146
 qlist_free_all mm/kasan/quarantine.c:165 [inline]
 kasan_quarantine_reduce+0x178/0x1d0 mm/kasan/quarantine.c:272
 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:438
 kasan_slab_alloc include/linux/kasan.h:259 [inline]
 slab_post_alloc_hook mm/slab.h:583 [inline]
 slab_alloc_node mm/slub.c:2954 [inline]
 slab_alloc mm/slub.c:2962 [inline]
 kmem_cache_alloc+0x1a2/0x380 mm/slub.c:2967
 getname_flags+0xba/0x650 fs/namei.c:141
 user_path_at_empty+0x2d/0x50 fs/namei.c:2726
 user_path_at include/linux/namei.h:59 [inline]
 vfs_statx+0x10a/0x3f0 fs/stat.c:193
 vfs_fstatat fs/stat.c:215 [inline]
 __do_sys_newfstatat fs/stat.c:384 [inline]
 __se_sys_newfstatat+0xc8/0x760 fs/stat.c:378
 __x64_sys_newfstatat+0x9b/0xb0 fs/stat.c:378

Memory state around the buggy address:
 ffff88814449ae00: fb fb fb fb fc fc fc fc 00 00 03 fc fc fc fc fc
 ffff88814449ae80: fb fb fb fb fc fc fc fc 00 00 00 04 fc fc fc fc
>ffff88814449af00: fa fb fb fb fc fc fc fc 00 00 01 fc fc fc fc fc
                      ^
 ffff88814449af80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff88814449b000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
general protection fault, probably for non-canonical address 0xf13bfc3e00000a68: 0000 [#1] PREEMPT SMP KASAN
KASAN: maybe wild-memory-access in range [0x89e001f000005340-0x89e001f000005347]
CPU: 0 PID: 21304 Comm: syz-executor.3 Tainted: G    B             5.10.102-syzkaller-00166-gcbfab5c59cf6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:io_cancel_defer_files fs/io_uring.c:8642 [inline]
RIP: 0010:io_uring_cancel_task_requests+0x580/0x2c50 fs/io_uring.c:8759
Code: 3c 08 00 74 08 4c 89 f7 e8 fd 71 e2 ff 4d 8b 36 4d 39 fe 74 40 49 8d 5e 10 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 d2 71 e2 ff 48 8b 3b 48 8b 74 24 18
RSP: 0018:ffffc90006b47700 EFLAGS: 00010803
RAX: 113c003e00000a68 RBX: 89e001f000005344 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000046 RDI: 0000000000000001
RBP: ffffc90006b47910 R08: ffffffff813fcc54 R09: fffffbfff0dc85b9
R10: fffffbfff0dc85b9 R11: 0000000000000000 R12: 1ffff11022abec0f
R13: ffff8881155f6000 R14: 89e001f000005334 R15: ffff8881155f6070
FS:  00007fde126d0700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fde127129d0 CR3: 000000014a060000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __io_uring_files_cancel+0x151/0x350 fs/io_uring.c:8845
 io_uring_files_cancel include/linux/io_uring.h:51 [inline]
 do_exit+0x2cc/0x23a0 kernel/exit.c:768
 do_group_exit+0x16a/0x2d0 kernel/exit.c:910
 get_signal+0x131f/0x1f70 kernel/signal.c:2780
 arch_do_signal+0x8d/0x620 arch/x86/kernel/signal.c:805
 exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
 exit_to_user_mode_prepare+0xaa/0xe0 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x24/0x40 kernel/entry/common.c:266
 do_syscall_64+0x3d/0x70 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fde135de059
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fde126d0168 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: 0000000000004000 RBX: 00007fde136f12a0 RCX: 00007fde135de059
RDX: 0000000000000000 RSI: 00000000000051f4 RDI: 0000000000000003
RBP: 00007fde1363808d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeff4a990f R14: 00007fde126d0300 R15: 0000000000022000
Modules linked in:
---[ end trace a1711cf0a715e61f ]---
RIP: 0010:io_cancel_defer_files fs/io_uring.c:8642 [inline]
RIP: 0010:io_uring_cancel_task_requests+0x580/0x2c50 fs/io_uring.c:8759
Code: 3c 08 00 74 08 4c 89 f7 e8 fd 71 e2 ff 4d 8b 36 4d 39 fe 74 40 49 8d 5e 10 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 d2 71 e2 ff 48 8b 3b 48 8b 74 24 18
RSP: 0018:ffffc90006b47700 EFLAGS: 00010803
RAX: 113c003e00000a68 RBX: 89e001f000005344 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000046 RDI: 0000000000000001
RBP: ffffc90006b47910 R08: ffffffff813fcc54 R09: fffffbfff0dc85b9
R10: fffffbfff0dc85b9 R11: 0000000000000000 R12: 1ffff11022abec0f
R13: ffff8881155f6000 R14: 89e001f000005334 R15: ffff8881155f6070
FS:  00007fde126d0700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fde127129d0 CR3: 000000014a060000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	3c 08                	cmp    $0x8,%al
   2:	00 74 08 4c          	add    %dh,0x4c(%rax,%rcx,1)
   6:	89 f7                	mov    %esi,%edi
   8:	e8 fd 71 e2 ff       	callq  0xffe2720a
   d:	4d 8b 36             	mov    (%r14),%r14
  10:	4d 39 fe             	cmp    %r15,%r14
  13:	74 40                	je     0x55
  15:	49 8d 5e 10          	lea    0x10(%r14),%rbx
  19:	48 89 d8             	mov    %rbx,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	48 89 df             	mov    %rbx,%rdi
  33:	e8 d2 71 e2 ff       	callq  0xffe2720a
  38:	48 8b 3b             	mov    (%rbx),%rdi
  3b:	48 8b 74 24 18       	mov    0x18(%rsp),%rsi

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/02/25 09:07 android12-5.10-lts cbfab5c59cf6 7c337266 .config console log report info ci2-android-5-10 KASAN: use-after-free Read in io_uring_cancel_task_requests
* Struck through repros no longer work on HEAD.