syzbot


KASAN: slab-use-after-free Read in update_rq_clock

Status: auto-obsoleted due to no activity on 2024/10/21 09:09
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+0d19f4435f893dfae27e@syzkaller.appspotmail.com
First crash: 114d, last: 114d

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in is_idle_task include/linux/sched.h:1878 [inline]
BUG: KASAN: slab-use-after-free in update_rq_clock_pelt kernel/sched/pelt.h:97 [inline]
BUG: KASAN: slab-use-after-free in update_rq_clock_task kernel/sched/core.c:775 [inline]
BUG: KASAN: slab-use-after-free in update_rq_clock+0x716/0x890 kernel/sched/core.c:797
Read of size 4 at addr ffff8880210d3c2c by task syz.4.38/5475

CPU: 1 UID: 0 PID: 5475 Comm: syz.4.38 Not tainted 6.11.0-rc4-next-20240822-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
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:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 is_idle_task include/linux/sched.h:1878 [inline]
 update_rq_clock_pelt kernel/sched/pelt.h:97 [inline]
 update_rq_clock_task kernel/sched/core.c:775 [inline]
 update_rq_clock+0x716/0x890 kernel/sched/core.c:797
 ttwu_queue kernel/sched/core.c:3939 [inline]
 try_to_wake_up+0x8a3/0x1480 kernel/sched/core.c:4266
 wake_up_process kernel/sched/core.c:4398 [inline]
 wake_up_q+0xc8/0x120 kernel/sched/core.c:1056
 futex_wake+0x523/0x5c0 kernel/futex/waitwake.c:199
 do_futex+0x392/0x560 kernel/futex/syscalls.c:107
 __do_sys_futex kernel/futex/syscalls.c:179 [inline]
 __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160
 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: 0033:0x7fb564f79e79
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:00007fb565caf0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fb565115f88 RCX: 00007fb564f79e79
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fb565115f8c
RBP: 00007fb565115f80 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000246 R12: 00007fb565115f8c
R13: 0000000000000000 R14: 00007ffec08059e0 R15: 00007ffec0805ac8
 </TASK>

Allocated by task 5471:
 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:4036 [inline]
 slab_alloc_node mm/slub.c:4085 [inline]
 kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4128
 alloc_task_struct_node kernel/fork.c:180 [inline]
 dup_task_struct+0x57/0x8c0 kernel/fork.c:1107
 copy_process+0x5d1/0x3d50 kernel/fork.c:2203
 kernel_clone+0x226/0x8f0 kernel/fork.c:2784
 __do_sys_clone3 kernel/fork.c:3088 [inline]
 __se_sys_clone3+0x2cb/0x350 kernel/fork.c:3067
 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 2549:
 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:579
 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:2299 [inline]
 slab_free mm/slub.c:4521 [inline]
 kmem_cache_free+0x195/0x3d0 mm/slub.c:4623
 put_task_struct include/linux/sched/task.h:139 [inline]
 delayed_put_task_struct+0x125/0x300 kernel/exit.c:228
 rcu_do_batch kernel/rcu/tree.c:2567 [inline]
 rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1037
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

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:541
 __call_rcu_common kernel/rcu/tree.c:3086 [inline]
 call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190
 context_switch kernel/sched/core.c:5314 [inline]
 __schedule+0x1852/0x4b30 kernel/sched/core.c:6677
 schedule_idle+0x53/0x90 kernel/sched/core.c:6795
 do_idle+0x56a/0x5d0 kernel/sched/idle.c:354
 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:424
 start_secondary+0x102/0x110 arch/x86/kernel/smpboot.c:313
 common_startup_64+0x13e/0x147

Second to 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:541
 task_work_add+0xb8/0x450 kernel/task_work.c:66
 task_tick_mm_cid kernel/sched/core.c:10422 [inline]
 sched_tick+0x322/0x610 kernel/sched/core.c:5594
 update_process_times+0x202/0x230 kernel/time/timer.c:2492
 tick_sched_handle kernel/time/tick-sched.c:276 [inline]
 tick_nohz_handler+0x37c/0x500 kernel/time/tick-sched.c:297
 __run_hrtimer kernel/time/hrtimer.c:1691 [inline]
 __hrtimer_run_queues+0x551/0xd50 kernel/time/hrtimer.c:1755
 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1026 [inline]
 __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1043
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1037
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

The buggy address belongs to the object at ffff8880210d3c00
 which belongs to the cache task_struct of size 7424
The buggy address is located 44 bytes inside of
 freed 7424-byte region [ffff8880210d3c00, ffff8880210d5900)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x210d0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880251dcdc1
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 00fff00000000040 ffff8880166fb500 ffffea0000848a00 dead000000000002
raw: 0000000000000000 0000000000040004 00000001fdffffff ffff8880251dcdc1
head: 00fff00000000040 ffff8880166fb500 ffffea0000848a00 dead000000000002
head: 0000000000000000 0000000000040004 00000001fdffffff ffff8880251dcdc1
head: 00fff00000000003 ffffea0000843401 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2, tgid 2 (kthreadd), ts 6575211411, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1517
 prep_new_page mm/page_alloc.c:1525 [inline]
 get_page_from_freelist+0x3131/0x3280 mm/page_alloc.c:3476
 __alloc_pages_noprof+0x29e/0x780 mm/page_alloc.c:4743
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x5f/0x120 mm/slub.c:2368
 allocate_slab+0x5a/0x2f0 mm/slub.c:2531
 new_slab mm/slub.c:2584 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3771
 __slab_alloc+0x58/0xa0 mm/slub.c:3861
 __slab_alloc_node mm/slub.c:3914 [inline]
 slab_alloc_node mm/slub.c:4073 [inline]
 kmem_cache_alloc_node_noprof+0x1fe/0x320 mm/slub.c:4128
 alloc_task_struct_node kernel/fork.c:180 [inline]
 dup_task_struct+0x57/0x8c0 kernel/fork.c:1107
 copy_process+0x5d1/0x3d50 kernel/fork.c:2203
 kernel_clone+0x226/0x8f0 kernel/fork.c:2784
 kernel_thread+0x1bc/0x240 kernel/fork.c:2846
 create_kthread kernel/kthread.c:412 [inline]
 kthreadd+0x60d/0x810 kernel/kthread.c:765
 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_owner free stack trace missing

Memory state around the buggy address:
 ffff8880210d3b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880210d3b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880210d3c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff8880210d3c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880210d3d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/22 09:09 linux-next 6a7917c89f21 ca02180f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in update_rq_clock
* Struck through repros no longer work on HEAD.