Message-ID: <678125df.050a0220.216c54.0011.GAE@google.com>
Date: Fri, 10 Jan 2025 05:51:27 -0800
From: syzbot <syzbot+3d92cfcfa84070b0a470@...kaller.appspotmail.com>
To: linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [kernel?] KASAN: slab-use-after-free Read in thread_group_cputime

Hello,

syzbot found the following issue on:

HEAD commit:    ccb98ccef0e5 Merge tag 'platform-drivers-x86-v6.13-4' of g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1377fac4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1c541fa8af5c9cc7
dashboard link: https://syzkaller.appspot.com/bug?extid=3d92cfcfa84070b0a470
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6e96673b1b94/disk-ccb98cce.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/528385411880/vmlinux-ccb98cce.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b061a4d50538/bzImage-ccb98cce.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3d92cfcfa84070b0a470@...kaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in thread_group_cputime+0x409/0x700 kernel/sched/cputime.c:341
Read of size 8 at addr ffff88803578c510 by task syz.2.3223/27552

CPU: 1 UID: 0 PID: 27552 Comm: syz.2.3223 Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 thread_group_cputime+0x409/0x700 kernel/sched/cputime.c:341
 thread_group_cputime_adjusted+0xa6/0x340 kernel/sched/cputime.c:639
 getrusage+0x1000/0x1340 kernel/sys.c:1863
 io_uring_show_fdinfo+0xdfe/0x1770 io_uring/fdinfo.c:197
 seq_show+0x608/0x770 fs/proc/fd.c:68
 seq_read_iter+0x43f/0xd70 fs/seq_file.c:230
 seq_read+0x3a9/0x4f0 fs/seq_file.c:162
 vfs_read+0x1fc/0xb70 fs/read_write.c:563
 ksys_read+0x18f/0x2b0 fs/read_write.c:708
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f277b585d29
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f277c409038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f277b775fa0 RCX: 00007f277b585d29
RDX: 00000000fffffd79 RSI: 0000000020000100 RDI: 0000000000000004
RBP: 00007f277b601b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f277b775fa0 R15: 00007f277b89fa28
 </TASK>

Allocated by task 27552:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4220
 alloc_task_struct_node kernel/fork.c:180 [inline]
 dup_task_struct+0x57/0x8c0 kernel/fork.c:1108
 copy_process+0x5d1/0x3d50 kernel/fork.c:2224
 create_io_thread+0x166/0x1d0 kernel/fork.c:2754
 io_sq_offload_create+0xa35/0x11b0 io_uring/sqpoll.c:477
 io_uring_create+0x68b/0xc00 io_uring/io_uring.c:3729
 io_uring_setup io_uring/io_uring.c:3811 [inline]
 __do_sys_io_uring_setup io_uring/io_uring.c:3838 [inline]
 __se_sys_io_uring_setup+0x2ba/0x330 io_uring/io_uring.c:3832
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6390:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4613 [inline]
 kmem_cache_free+0x195/0x410 mm/slub.c:4715
 put_task_struct include/linux/sched/task.h:144 [inline]
 delayed_put_task_struct+0x125/0x300 kernel/exit.c:227
 rcu_do_batch kernel/rcu/tree.c:2567 [inline]
 rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
 do_softirq+0x11b/0x1e0 kernel/softirq.c:462
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:389
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
 nsim_dev_trap_report_work+0x7c4/0xb50 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544
 __call_rcu_common kernel/rcu/tree.c:3086 [inline]
 call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190
 context_switch kernel/sched/core.c:5372 [inline]
 __schedule+0x1858/0x4c30 kernel/sched/core.c:6756
 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6935
 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6959
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irq+0x44/0x50 kernel/locking/spinlock.c:202
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 do_group_exit+0x1f7/0x2c0 kernel/exit.c:1084
 __do_sys_exit_group kernel/exit.c:1098 [inline]
 __se_sys_exit_group kernel/exit.c:1096 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096
 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88803578bc00
 which belongs to the cache task_struct of size 7424
The buggy address is located 2320 bytes inside of
 freed 7424-byte region [ffff88803578bc00, ffff88803578d900)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x35788
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888033adae01
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801bafe500 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000040004 00000001f5000000 ffff888033adae01
head: 00fff00000000040 ffff88801bafe500 0000000000000000 dead000000000001
head: 0000000000000000 0000000000040004 00000001f5000000 ffff888033adae01
head: 00fff00000000003 ffffea0000d5e201 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 2, tgid 2 (kthreadd), ts 59377995710, free_ts 59377910116
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558
 prep_new_page mm/page_alloc.c:1566 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3476
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_slab_page+0x59/0x110 mm/slub.c:2425
 allocate_slab+0x5a/0x2b0 mm/slub.c:2589
 new_slab mm/slub.c:2642 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3830
 __slab_alloc+0x58/0xa0 mm/slub.c:3920
 __slab_alloc_node mm/slub.c:3995 [inline]
 slab_alloc_node mm/slub.c:4156 [inline]
 kmem_cache_alloc_node_noprof+0x269/0x380 mm/slub.c:4220
 alloc_task_struct_node kernel/fork.c:180 [inline]
 dup_task_struct+0x57/0x8c0 kernel/fork.c:1108
 copy_process+0x5d1/0x3d50 kernel/fork.c:2224
 kernel_clone+0x226/0x8e0 kernel/fork.c:2806
 kernel_thread+0x1bc/0x240 kernel/fork.c:2868
 create_kthread kernel/kthread.c:412 [inline]
 kthreadd+0x60d/0x810 kernel/kthread.c:767
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 5833 tgid 5833 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0xd3f/0x1010 mm/page_alloc.c:2659
 discard_slab mm/slub.c:2688 [inline]
 __put_partials+0x160/0x1c0 mm/slub.c:3157
 put_cpu_partial+0x17c/0x250 mm/slub.c:3232
 __slab_free+0x290/0x380 mm/slub.c:4483
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 __kmalloc_cache_node_noprof+0x1ec/0x3a0 mm/slub.c:4337
 kmalloc_node_noprof include/linux/slab.h:924 [inline]
 alloc_worker kernel/workqueue.c:2638 [inline]
 create_worker+0x11b/0x720 kernel/workqueue.c:2781
 maybe_create_worker kernel/workqueue.c:3054 [inline]
 manage_workers kernel/workqueue.c:3106 [inline]
 worker_thread+0x318/0xd30 kernel/workqueue.c:3366
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff88803578c400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803578c480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88803578c500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88803578c580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803578c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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