syzbot

Code: ff 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 7c 24 f0 48 89 74 24 e8 48 89 54 24 e0 48 8b 44 24 f0 48 8b 54 24 e8 48 8b 4c 24 e0 <8b> b0 0c 01 00 00 f3 0f 6f 01 c1 e6 04 0f 11 02 f3 0f 6f 49 10 81
==================================================================
BUG: KASAN: use-after-free in io_fallback_tw+0x6d/0x119 io_uring/io_uring.c:1249
Read of size 8 at addr ffff888028d33948 by task syz-executor371/5070

CPU: 1 PID: 5070 Comm: syz-executor371 Not tainted 6.2.0-rc3-next-20230112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:306 [inline]
 print_report+0x15e/0x45d mm/kasan/report.c:417
 kasan_report+0xc0/0xf0 mm/kasan/report.c:517
 io_fallback_tw+0x6d/0x119 io_uring/io_uring.c:1249
 tctx_task_work.cold+0xf/0x2c io_uring/io_uring.c:1219
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xb17/0x2a90 kernel/exit.c:867
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1012
 get_signal+0x225f/0x24f0 kernel/signal.c:2859
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:310
 exc_page_fault+0xc0/0x170 arch/x86/mm/fault.c:1557
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7ff7d332e08e
Code: Unable to access opcode bytes at 0x7ff7d332e064.
RSP: 002b:00007fffc08a9bc8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ff7d332f1e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff7d332f270
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 5070:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 __kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:325
 kasan_slab_alloc include/linux/kasan.h:186 [inline]
 slab_post_alloc_hook mm/slab.h:769 [inline]
 kmem_cache_alloc_bulk+0x3aa/0x730 mm/slub.c:4033
 __io_alloc_req_refill+0xcc/0x40b io_uring/io_uring.c:1062
 io_alloc_req_refill io_uring/io_uring.h:348 [inline]
 io_submit_sqes.cold+0x7c/0xc2 io_uring/io_uring.c:2407
 __do_sys_io_uring_enter+0x9e4/0x2c10 io_uring/io_uring.c:3429
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 33:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
 kasan_slab_free include/linux/kasan.h:162 [inline]
 slab_free_hook mm/slub.c:1781 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807
 slab_free mm/slub.c:3787 [inline]
 kmem_cache_free+0xec/0x4e0 mm/slub.c:3809
 io_req_caches_free+0x1a9/0x1e6 io_uring/io_uring.c:2737
 io_ring_exit_work+0x2e7/0xc80 io_uring/io_uring.c:2967
 process_one_work+0x9bf/0x1750 kernel/workqueue.c:2293
 worker_thread+0x669/0x1090 kernel/workqueue.c:2440
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

The buggy address belongs to the object at ffff888028d338c0
 which belongs to the cache io_kiocb of size 216
The buggy address is located 136 bytes inside of
 216-byte region [ffff888028d338c0, ffff888028d33998)

The buggy address belongs to the physical page:
page:ffffea0000a34cc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28d33
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffff88814633b280 dead000000000122 0000000000000000
raw: 0000000000000000 00000000800c000c 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5070, tgid 5070 (syz-executor371), ts 55651699541, free_ts 55645844106
 prep_new_page mm/page_alloc.c:2549 [inline]
 get_page_from_freelist+0x11bb/0x2d50 mm/page_alloc.c:4324
 __alloc_pages+0x1cb/0x5c0 mm/page_alloc.c:5590
 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2281
 alloc_slab_page mm/slub.c:1851 [inline]
 allocate_slab+0x25f/0x350 mm/slub.c:1998
 new_slab mm/slub.c:2051 [inline]
 ___slab_alloc+0xa91/0x1400 mm/slub.c:3193
 __kmem_cache_alloc_bulk mm/slub.c:3951 [inline]
 kmem_cache_alloc_bulk+0x23d/0x730 mm/slub.c:4026
 __io_alloc_req_refill+0xcc/0x40b io_uring/io_uring.c:1062
 io_alloc_req_refill io_uring/io_uring.h:348 [inline]
 io_submit_sqes.cold+0x7c/0xc2 io_uring/io_uring.c:2407
 __do_sys_io_uring_enter+0x9e4/0x2c10 io_uring/io_uring.c:3429
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1451 [inline]
 free_pcp_prepare+0x4d0/0x910 mm/page_alloc.c:1501
 free_unref_page_prepare mm/page_alloc.c:3387 [inline]
 free_unref_page_list+0x176/0xcd0 mm/page_alloc.c:3528
 release_pages+0xcb1/0x1330 mm/swap.c:1072
 tlb_batch_pages_flush+0xa8/0x1a0 mm/mmu_gather.c:97
 tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
 tlb_flush_mmu mm/mmu_gather.c:299 [inline]
 tlb_finish_mmu+0x14b/0x7e0 mm/mmu_gather.c:391
 exit_mmap+0x202/0x7c0 mm/mmap.c:3100
 __mmput+0x128/0x4c0 kernel/fork.c:1212
 mmput+0x60/0x70 kernel/fork.c:1234
 exec_mmap fs/exec.c:1034 [inline]
 begin_new_exec+0x1027/0x2f80 fs/exec.c:1293
 load_elf_binary+0x801/0x4ff0 fs/binfmt_elf.c:1001
 search_binary_handler fs/exec.c:1736 [inline]
 exec_binprm fs/exec.c:1778 [inline]
 bprm_execve fs/exec.c:1853 [inline]
 bprm_execve+0x7fd/0x1ae0 fs/exec.c:1809
 do_execveat_common+0x72c/0x880 fs/exec.c:1960
 do_execve fs/exec.c:2034 [inline]
 __do_sys_execve fs/exec.c:2110 [inline]
 __se_sys_execve fs/exec.c:2105 [inline]
 __x64_sys_execve+0x93/0xc0 fs/exec.c:2105
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff888028d33800: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
 ffff888028d33880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
>ffff888028d33900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff888028d33980: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888028d33a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	ff 66 2e             	jmpq   *0x2e(%rsi)
   3:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
   a:	00
   b:	90                   	nop
   c:	48 89 7c 24 f0       	mov    %rdi,-0x10(%rsp)
  11:	48 89 74 24 e8       	mov    %rsi,-0x18(%rsp)
  16:	48 89 54 24 e0       	mov    %rdx,-0x20(%rsp)
  1b:	48 8b 44 24 f0       	mov    -0x10(%rsp),%rax
  20:	48 8b 54 24 e8       	mov    -0x18(%rsp),%rdx
  25:	48 8b 4c 24 e0       	mov    -0x20(%rsp),%rcx
* 2a:	8b b0 0c 01 00 00    	mov    0x10c(%rax),%esi <-- trapping instruction
  30:	f3 0f 6f 01          	movdqu (%rcx),%xmm0
  34:	c1 e6 04             	shl    $0x4,%esi
  37:	0f 11 02             	movups %xmm0,(%rdx)
  3a:	f3 0f 6f 49 10       	movdqu 0x10(%rcx),%xmm1
  3f:	81                   	.byte 0x81