From: syzbot <[email protected]>
To: [email protected], [email protected],
[email protected], [email protected],
[email protected]
Subject: Re: [syzbot] KASAN: use-after-free Read in io_fallback_req_func
Date: Thu, 12 Jan 2023 07:24:43 -0800 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
syzbot has found a reproducer for the following issue on:
HEAD commit: 0a093b2893c7 Add linux-next specific files for 20230112
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=176167ba480000
kernel config: https://syzkaller.appspot.com/x/.config?x=835f3591019836d5
dashboard link: https://syzkaller.appspot.com/bug?extid=bc022c162e3b001bf607
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17d58fbe480000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=151b0316480000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8111a570d6cb/disk-0a093b28.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ecc135b7fc9a/vmlinux-0a093b28.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ca8d73b446ea/bzImage-0a093b28.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]
==================================================================
BUG: KASAN: use-after-free in io_fallback_req_func+0xc7/0x204 io_uring/io_uring.c:251
Read of size 8 at addr ffff8880793aa948 by task kworker/0:3/4401
CPU: 0 PID: 4401 Comm: kworker/0:3 Not tainted 6.2.0-rc3-next-20230112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: events io_fallback_req_func
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_req_func+0xc7/0x204 io_uring/io_uring.c:251
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
</TASK>
Allocated by task 5077:
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 31:
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 ffff8880793aa8c0
which belongs to the cache io_kiocb of size 216
The buggy address is located 136 bytes inside of
216-byte region [ffff8880793aa8c0, ffff8880793aa998)
The buggy address belongs to the physical page:
page:ffffea0001e4ea80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x793aa
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffff88814610fc80 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 5077, tgid 5077 (syz-executor134), ts 60034717602, free_ts 59988620363
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
exit_mm kernel/exit.c:563 [inline]
do_exit+0x9ac/0x2a90 kernel/exit.c:854
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
Memory state around the buggy address:
ffff8880793aa800: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
ffff8880793aa880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
>ffff8880793aa900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880793aa980: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880793aaa00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
next prev parent reply other threads:[~2023-01-12 15:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-12 10:09 [syzbot] KASAN: use-after-free Read in io_fallback_req_func syzbot
2023-01-12 10:37 ` Pavel Begunkov
2023-01-12 10:38 ` syzbot
2023-01-12 15:24 ` syzbot [this message]
2023-01-12 17:42 ` Jens Axboe
2023-01-13 2:26 ` syzbot
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