[syzbot] [kernel?] KASAN: slab-use-after-free Read in reweight_entity

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9a3dad63edbe Merge tag '6.6-rc5-ksmbd-server-fixes' of git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1413e691680000
kernel config: https://syzkaller.appspot.com/x/.config?x=5d83dadac33c08b7
dashboard link: https://syzkaller.appspot.com/bug?extid=3908cdfd655fd839c82f
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12a055f9680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=103ef619680000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-9a3dad63.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/98467f6633b7/vmlinux-9a3dad63.xz
kernel image: https://storage.googleapis.com/syzbot-assets/93b5cb4a26b0/bzImage-9a3dad63.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3908cd...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in __update_min_deadline kernel/sched/fair.c:805 [inline]
BUG: KASAN: slab-use-after-free in min_deadline_update kernel/sched/fair.c:819 [inline]
BUG: KASAN: slab-use-after-free in min_deadline_cb_propagate kernel/sched/fair.c:825 [inline]
BUG: KASAN: slab-use-after-free in reweight_entity+0x8e3/0xa60 kernel/sched/fair.c:3660
Read of size 8 at addr ffff888022a59a70 by task syz-executor206/5331

CPU: 3 PID: 5331 Comm: syz-executor206 Not tainted 6.6.0-rc5-syzkaller-00267-g9a3dad63edbe #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xc4/0x620 mm/kasan/report.c:475
kasan_report+0xda/0x110 mm/kasan/report.c:588
__update_min_deadline kernel/sched/fair.c:805 [inline]
min_deadline_update kernel/sched/fair.c:819 [inline]
min_deadline_cb_propagate kernel/sched/fair.c:825 [inline]
reweight_entity+0x8e3/0xa60 kernel/sched/fair.c:3660
entity_tick kernel/sched/fair.c:5317 [inline]
task_tick_fair+0xee/0xcd0 kernel/sched/fair.c:12392
scheduler_tick+0x210/0x650 kernel/sched/core.c:5657
update_process_times+0x19f/0x220 kernel/time/timer.c:2076
tick_sched_handle+0x8e/0x170 kernel/time/tick-sched.c:254
tick_sched_timer+0xe9/0x110 kernel/time/tick-sched.c:1492
__run_hrtimer kernel/time/hrtimer.c:1688 [inline]
__hrtimer_run_queues+0x647/0xc10 kernel/time/hrtimer.c:1752
hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1063 [inline]
__sysvec_apic_timer_interrupt+0x105/0x3f0 arch/x86/kernel/apic/apic.c:1080
sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1074
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline]
RIP: 0010:rcu_is_watching+0x39/0xb0 kernel/rcu/tree.c:699
Code: a5 cf 08 48 c7 c3 e8 6d 03 00 83 f8 07 89 c5 77 7a 48 8d 3c ed 40 ba 5c 8c 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 54 48 03 1c ed 40 ba 5c 8c 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc90003cc73d8 EFLAGS: 00000a06
RAX: dffffc0000000000 RBX: 0000000000036de8 RCX: 1ffffffff1d9a7c0
RDX: 1ffffffff18b974b RSI: ffffffff8ae90aa0 RDI: ffffffff8c5cba58
RBP: 0000000000000003 R08: 0000000000000007 R09: ffffffffff600000
R10: 00007fcac0348000 R11: dffffc0000000000 R12: ffffc90003cc7488
R13: ffffffff81747dc0 R14: ffffc90003cc7500 R15: ffff88802787c780
kernel_text_address kernel/extable.c:113 [inline]
kernel_text_address+0x62/0xd0 kernel/extable.c:94
__kernel_text_address+0xd/0x30 kernel/extable.c:79
unwind_get_return_address+0x78/0xe0 arch/x86/kernel/unwind_orc.c:369
arch_stack_walk+0xbe/0x170 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
__kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook mm/slab.h:762 [inline]
slab_alloc_node mm/slab.c:3237 [inline]
slab_alloc mm/slab.c:3246 [inline]
__kmem_cache_alloc_lru mm/slab.c:3423 [inline]
kmem_cache_alloc+0x159/0x400 mm/slab.c:3432
kmem_cache_zalloc include/linux/slab.h:710 [inline]
alloc_buffer_head+0x21/0x140 fs/buffer.c:3023
folio_alloc_buffers+0x2e7/0x7f0 fs/buffer.c:935
folio_create_empty_buffers+0x36/0x470 fs/buffer.c:1648
ext4_block_write_begin+0xcc4/0xf10 fs/ext4/inode.c:1024
ext4_da_write_begin+0x40a/0x8c0 fs/ext4/inode.c:2890
generic_perform_write+0x278/0x600 mm/filemap.c:3969
ext4_buffered_write_iter+0x11f/0x3c0 fs/ext4/file.c:299
ext4_file_write_iter+0x7f7/0x1860 fs/ext4/file.c:717
call_write_iter include/linux/fs.h:1956 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x650/0xe40 fs/read_write.c:584
ksys_write+0x12f/0x250 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fcac0348789
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 18 00 00 90 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:00007fff03860d58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fcac0348789
RDX: 000000000208e24b RSI: 0000000020000100 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff03860d7c
R13: 00007fff03860d90 R14: 00007fff03860dd0 R15: 0000000000000015
</TASK>

Allocated by task 2:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
__kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook mm/slab.h:762 [inline]
slab_alloc_node mm/slab.c:3237 [inline]
kmem_cache_alloc_node+0x173/0x540 mm/slab.c:3509
alloc_task_struct_node kernel/fork.c:173 [inline]
dup_task_struct kernel/fork.c:1110 [inline]
copy_process+0x41c/0x73f0 kernel/fork.c:2327
kernel_clone+0xfd/0x920 kernel/fork.c:2909
kernel_thread+0xc0/0x100 kernel/fork.c:2971
create_kthread kernel/kthread.c:411 [inline]
kthreadd+0x4fb/0x7d0 kernel/kthread.c:746
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Freed by task 21:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
____kasan_slab_free mm/kasan/common.c:236 [inline]
____kasan_slab_free+0x138/0x190 mm/kasan/common.c:200
kasan_slab_free include/linux/kasan.h:164 [inline]
__cache_free mm/slab.c:3370 [inline]
__do_kmem_cache_free mm/slab.c:3557 [inline]
kmem_cache_free+0x104/0x380 mm/slab.c:3582
put_task_struct include/linux/sched/task.h:136 [inline]
put_task_struct include/linux/sched/task.h:123 [inline]
delayed_put_task_struct+0x21b/0x2b0 kernel/exit.c:226
rcu_do_batch kernel/rcu/tree.c:2139 [inline]
rcu_core+0x805/0x1bb0 kernel/rcu/tree.c:2403
__do_softirq+0x218/0x965 kernel/softirq.c:553

Last potentially related work creation:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
__kasan_record_aux_stack+0x78/0x80 mm/kasan/generic.c:492
__call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2653
put_task_struct_rcu_user kernel/exit.c:232 [inline]
put_task_struct_rcu_user+0x87/0xc0 kernel/exit.c:229
context_switch kernel/sched/core.c:5385 [inline]
__schedule+0xee9/0x5a10 kernel/sched/core.c:6695
schedule+0xe7/0x1b0 kernel/sched/core.c:6771
schedule_timeout+0x278/0x2c0 kernel/time/timer.c:2143
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common+0x3e0/0x5f0 kernel/sched/completion.c:116
kthread_stop+0x18e/0x5f0 kernel/kthread.c:709
kvm_mmu_pre_destroy_vm+0x44/0x60 arch/x86/kvm/mmu/mmu.c:7160
kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1313 [inline]
kvm_put_kvm+0x254/0xad0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1373
kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1396
__fput+0x3f7/0xa70 fs/file_table.c:384
__fput_sync+0x47/0x50 fs/file_table.c:465
__do_sys_close fs/open.c:1572 [inline]
__se_sys_close fs/open.c:1557 [inline]
__x64_sys_close+0x87/0xf0 fs/open.c:1557
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Second to last potentially related work creation:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
__kasan_record_aux_stack+0x78/0x80 mm/kasan/generic.c:492
__call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2653
put_task_struct_rcu_user kernel/exit.c:232 [inline]
put_task_struct_rcu_user+0x87/0xc0 kernel/exit.c:229
context_switch kernel/sched/core.c:5385 [inline]
__schedule+0xee9/0x5a10 kernel/sched/core.c:6695
schedule+0xe7/0x1b0 kernel/sched/core.c:6771
schedule_timeout+0x278/0x2c0 kernel/time/timer.c:2143
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common+0x3e0/0x5f0 kernel/sched/completion.c:116
kthread_stop+0x18e/0x5f0 kernel/kthread.c:709
kvm_mmu_pre_destroy_vm+0x44/0x60 arch/x86/kvm/mmu/mmu.c:7160
kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1313 [inline]
kvm_put_kvm+0x254/0xad0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1373
kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1396
__fput+0x3f7/0xa70 fs/file_table.c:384
__fput_sync+0x47/0x50 fs/file_table.c:465
__do_sys_close fs/open.c:1572 [inline]
__se_sys_close fs/open.c:1557 [inline]
__x64_sys_close+0x87/0xf0 fs/open.c:1557
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff888022a599c0
which belongs to the cache task_struct of size 8960
The buggy address is located 176 bytes inside of
freed 8960-byte region [ffff888022a599c0, ffff888022a5bcc0)

The buggy address belongs to the physical page:
page:ffffea00008a9600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x22a58
head:ffffea00008a9600 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0x1()
raw: 00fff00000000840 ffff88810005a500 ffffea00009ffb10 ffffea0000bf6410
raw: 0000000000000000 ffff888022a599c0 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x2420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 4949, tgid 4949 (dhcpcd-run-hook), ts 26983961004, free_ts 23254563577
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536
prep_new_page mm/page_alloc.c:1543 [inline]
get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170
__alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426
__alloc_pages_node include/linux/gfp.h:237 [inline]
kmem_getpages mm/slab.c:1356 [inline]
cache_grow_begin+0x99/0x3a0 mm/slab.c:2550
cache_alloc_refill+0x294/0x3a0 mm/slab.c:2923
____cache_alloc mm/slab.c:2999 [inline]
____cache_alloc mm/slab.c:2982 [inline]
__do_cache_alloc mm/slab.c:3182 [inline]
slab_alloc_node mm/slab.c:3230 [inline]
kmem_cache_alloc_node+0x481/0x540 mm/slab.c:3509
alloc_task_struct_node kernel/fork.c:173 [inline]
dup_task_struct kernel/fork.c:1110 [inline]
copy_process+0x41c/0x73f0 kernel/fork.c:2327
kernel_clone+0xfd/0x920 kernel/fork.c:2909
__do_sys_clone+0xba/0x100 kernel/fork.c:3052
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 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:1136 [inline]
free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2312
free_unref_page+0x33/0x3b0 mm/page_alloc.c:2405
slab_destroy mm/slab.c:1608 [inline]
slabs_destroy+0x85/0xc0 mm/slab.c:1628
cache_flusharray mm/slab.c:3341 [inline]
___cache_free+0x2b7/0x420 mm/slab.c:3404
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x4c/0x1b0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook mm/slab.h:762 [inline]
slab_alloc_node mm/slab.c:3237 [inline]
kmem_cache_alloc_node+0x173/0x540 mm/slab.c:3509
__alloc_skb+0x287/0x330 net/core/skbuff.c:640
alloc_skb include/linux/skbuff.h:1286 [inline]
alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6313
sock_alloc_send_pskb+0x7e4/0x970 net/core/sock.c:2795
unix_dgram_sendmsg+0x455/0x1c30 net/unix/af_unix.c:1953
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0xd5/0x180 net/socket.c:745
sock_write_iter+0x29b/0x3d0 net/socket.c:1158
call_write_iter include/linux/fs.h:1956 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x650/0xe40 fs/read_write.c:584
ksys_write+0x1f0/0x250 fs/read_write.c:637

Memory state around the buggy address:
ffff888022a59900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888022a59980: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
>ffff888022a59a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888022a59a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888022a59b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess), 3 bytes skipped:
0: 48 c7 c3 e8 6d 03 00 mov $0x36de8,%rbx
7: 83 f8 07 cmp $0x7,%eax
a: 89 c5 mov %eax,%ebp
c: 77 7a ja 0x88
e: 48 8d 3c ed 40 ba 5c lea -0x73a345c0(,%rbp,8),%rdi
15: 8c
16: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
1d: fc ff df
20: 48 89 fa mov %rdi,%rdx
23: 48 c1 ea 03 shr $0x3,%rdx
* 27: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2b: 75 54 jne 0x81
2d: 48 03 1c ed 40 ba 5c add -0x73a345c0(,%rbp,8),%rbx
34: 8c
35: 48 rex.W
36: b8 00 00 00 00 mov $0x0,%eax
3b: 00 fc add %bh,%ah


---
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[Peter Zijlstra]

On Tue, Oct 17, 2023 at 07:58:56PM +0100, Dmitry Safonov wrote:
> FWIW,
> Managed to locally reproduce it twice on 58720809f527 (tag: v6.6-rc6)
> Linux 6.6-rc6 + TCP-AO patches on the top.
> (but can't reproduce reliably at will)
>
> [dima@Mindolluin linux-tcp-ao]$ ./scripts/faddr2line vmlinux
> reweight_entity+0x3b0/0x490
> reweight_entity+0x3b0/0x490:

Could you please try:

https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?h=sched/urgent&id=a3b75dce9d9ae4510ea75b655567f50622f48706


---
Subject: sched/eevdf: Fix heap corruption more
From: Peter Zijlstra <pet...@infradead.org>
Date: Tue Oct 17 16:59:47 CEST 2023

Because someone is a flaming idiot... :/

Fixes: 8dafa9d0eb1a ("sched/eevdf: Fix min_deadline heap integrity")
Reported-by: 0599j...@gmail.com
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218020
---
kernel/sched/fair.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3699,7 +3699,8 @@ static void reweight_entity(struct cfs_r
*/
deadline = div_s64(deadline * old_weight, weight);
se->deadline = se->vruntime + deadline;
- min_deadline_cb_propagate(&se->run_node, NULL);
+ if (se != cfs_rq->curr)
+ min_deadline_cb_propagate(&se->run_node, NULL);
}

#ifdef CONFIG_SMP

[Dmitry Safonov]

On 10/17/23 20:07, Peter Zijlstra wrote:
> On Tue, Oct 17, 2023 at 07:58:56PM +0100, Dmitry Safonov wrote:
>> FWIW,
>> Managed to locally reproduce it twice on 58720809f527 (tag: v6.6-rc6)
>> Linux 6.6-rc6 + TCP-AO patches on the top.
>> (but can't reproduce reliably at will)
>>
>> [dima@Mindolluin linux-tcp-ao]$ ./scripts/faddr2line vmlinux
>> reweight_entity+0x3b0/0x490
>> reweight_entity+0x3b0/0x490:
>
> Could you please try:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?h=sched/urgent&id=a3b75dce9d9ae4510ea75b655567f50622f48706

I've run a hundred times the test that previously hit it twice, no
reproductions.

> ---
> Subject: sched/eevdf: Fix heap corruption more
> From: Peter Zijlstra <pet...@infradead.org>
> Date: Tue Oct 17 16:59:47 CEST 2023
>
> Because someone is a flaming idiot... :/
>
> Fixes: 8dafa9d0eb1a ("sched/eevdf: Fix min_deadline heap integrity")
> Reported-by: 0599j...@gmail.com
> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=218020
> ---
> kernel/sched/fair.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -3699,7 +3699,8 @@ static void reweight_entity(struct cfs_r
> */
> deadline = div_s64(deadline * old_weight, weight);
> se->deadline = se->vruntime + deadline;
> - min_deadline_cb_propagate(&se->run_node, NULL);
> + if (se != cfs_rq->curr)
> + min_deadline_cb_propagate(&se->run_node, NULL);
> }
>
> #ifdef CONFIG_SMP

Thanks,
Dmitry

[Dmitry Safonov]

FWIW,
Managed to locally reproduce it twice on 58720809f527 (tag: v6.6-rc6)
Linux 6.6-rc6 + TCP-AO patches on the top.
(but can't reproduce reliably at will)

[dima@Mindolluin linux-tcp-ao]$ ./scripts/faddr2line vmlinux
reweight_entity+0x3b0/0x490
reweight_entity+0x3b0/0x490:

__update_min_deadline at kernel/sched/fair.c:805
(inlined by) min_deadline_update at kernel/sched/fair.c:819
(inlined by) min_deadline_cb_propagate at kernel/sched/fair.c:825
(inlined by) reweight_entity at kernel/sched/fair.c:3660

[ 258.450573] TCP: AO key not found for (10.0.1.1,
58651)->(10.0.254.1, 7018) S keyid: 100 L3index: 0
[ 259.482680] ==================================================================
[ 259.483732] BUG: KASAN: slab-use-after-free in reweight_entity+0x3b0/0x490
[ 259.484564] Read of size 8 at addr ffff88800859dcf0 by task
unsigned-md5_ip/2535

[ 259.485593] CPU: 0 PID: 2535 Comm: unsigned-md5_ip Not tainted 6.6.0-rc6+ #7
[ 259.486393] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
BIOS Arch Linux 1.16.2-2-2 04/01/2014
[ 259.487445] Call Trace:
[ 259.487783] <TASK>
[ 259.488057] dump_stack_lvl+0x46/0x70
[ 259.488578] print_report+0xc5/0x610
[ 259.489099] ? lock_acquire+0x162/0x3d0
[ 259.489641] ? __virt_addr_valid+0xbe/0x130
[ 259.490211] kasan_report+0xbe/0xf0
[ 259.490902] ? reweight_entity+0x3b0/0x490
[ 259.491683] ? reweight_entity+0x3b0/0x490
[ 259.492475] reweight_entity+0x3b0/0x490
[ 259.493319] enqueue_task_fair+0x944/0xc90
[ 259.494146] activate_task+0x95/0x1b0
[ 259.494932] ttwu_do_activate+0x91/0x3c0
[ 259.495645] try_to_wake_up+0x423/0xd60
[ 259.496425] ? sched_ttwu_pending+0x260/0x260
[ 259.497543] ? _raw_spin_unlock+0x29/0x40
[ 259.498301] wake_up_q+0x6f/0xf0
[ 259.498889] __mutex_unlock_slowpath+0x19b/0x3e0
[ 259.500191] ? bit_wait_io_timeout+0xc0/0xc0
[ 259.501691] ? reacquire_held_locks+0x280/0x280
[ 259.502634] ? rcu_is_watching+0x34/0x50
[ 259.503485] __rtnl_unlock+0x3f/0x80
[ 259.504089] netdev_run_todo+0x1b7/0x840
[ 259.504721] ? generic_xdp_install+0x2a0/0x2a0
[ 259.505394] ? __kmem_cache_free+0x192/0x2b0
[ 259.506021] ? rtnl_newlink+0x59/0x70
[ 259.506562] rtnetlink_rcv_msg+0x200/0x650
[ 259.507088] ? rtnl_getlink+0x590/0x590
[ 259.507600] ? lockdep_hardirqs_on_prepare+0x220/0x220
[ 259.508247] ? find_held_lock+0x8a/0xa0
[ 259.508750] ? local_clock_noinstr+0x9/0xb0
[ 259.509254] netlink_rcv_skb+0xdd/0x210
[ 259.509751] ? rtnl_getlink+0x590/0x590
[ 259.510214] ? netlink_ack+0x840/0x840
[ 259.511082] ? lock_sync+0x100/0x100
[ 259.511775] ? __rcu_read_unlock+0x6b/0x2a0
[ 259.512822] ? netlink_deliver_tap+0xfe/0x620
[ 259.513527] netlink_unicast+0x2f3/0x480
[ 259.514105] ? netlink_attachskb+0x440/0x440
[ 259.514642] netlink_sendmsg+0x3c0/0x6e0
[ 259.515108] ? netlink_unicast+0x480/0x480
[ 259.515572] ? netlink_unicast+0x480/0x480
[ 259.516030] __sock_sendmsg+0x73/0xc0
[ 259.516425] __sys_sendto+0x18b/0x210
[ 259.516878] ? __ia32_sys_getpeername+0x50/0x50
[ 259.517435] ? mark_held_locks+0x1a/0x80
[ 259.517949] __x64_sys_sendto+0x72/0x80
[ 259.518457] do_syscall_64+0x35/0x80
[ 259.518945] entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 259.519626] RIP: 0033:0x7f62cf55f9ec
[ 259.520117] Code: 89 4c 24 1c e8 a5 63 f7 ff 44 8b 54 24 1c 8b 3c
24 45 31 c9 89 c5 48 8b 54 24 10 48 8b 74 24 08 45 31 c0 b8 2c 00 00
00 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 04 24 e8 f1 63 f7 ff 48
8b 04
[ 259.522762] RSP: 002b:00007ffddd3c4c90 EFLAGS: 00000246 ORIG_RAX:
000000000000002c
[ 259.523854] RAX: ffffffffffffffda RBX: 00007ffddd3c4cd0 RCX: 00007f62cf55f9ec
[ 259.524768] RDX: 0000000000000044 RSI: 00007ffddd3c4cd0 RDI: 0000000000000006
[ 259.525679] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[ 259.526585] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000038
[ 259.528558] R13: 0000000000000006 R14: 00007ffddd3c4cfc R15: 00007ffddd3c4d08
[ 259.529452] </TASK>

[ 259.529950] Allocated by task 31:
[ 259.530390] kasan_save_stack+0x21/0x40
[ 259.530904] kasan_set_track+0x21/0x30
[ 259.531399] __kasan_slab_alloc+0x62/0x70
[ 259.531946] kmem_cache_alloc_node+0x187/0x370
[ 259.532551] copy_process+0x2c4/0x3460
[ 259.533080] kernel_clone+0xf6/0x570
[ 259.533553] user_mode_thread+0xab/0xe0
[ 259.534067] call_usermodehelper_exec_work+0x78/0xb0
[ 259.534713] process_one_work+0x439/0x8d0
[ 259.535240] worker_thread+0x393/0x680
[ 259.535733] kthread+0x1ad/0x1f0
[ 259.536192] ret_from_fork+0x2d/0x50
[ 259.536682] ret_from_fork_asm+0x11/0x20

[ 259.537439] Freed by task 21:
[ 259.537837] kasan_save_stack+0x21/0x40
[ 259.538350] kasan_set_track+0x21/0x30
[ 259.538864] kasan_save_free_info+0x27/0x40
[ 259.539427] __kasan_slab_free+0x106/0x180
[ 259.539932] kmem_cache_free+0x1d4/0x460
[ 259.540437] delayed_put_task_struct+0x131/0x170
[ 259.541068] rcu_core+0x63d/0x1470
[ 259.541494] __do_softirq+0x10f/0x51b

[ 259.542145] Last potentially related work creation:
[ 259.542746] kasan_save_stack+0x21/0x40
[ 259.544124] __kasan_record_aux_stack+0x94/0xa0
[ 259.545804] __call_rcu_common.constprop.0+0x47/0x620
[ 259.546507] __schedule+0x74c/0x1490
[ 259.547010] schedule+0x81/0xe0
[ 259.547458] schedule_timeout+0x138/0x2a0
[ 259.548006] rcu_gp_fqs_loop+0x1c0/0x990
[ 259.548522] rcu_gp_kthread+0x307/0x3a0
[ 259.549032] kthread+0x1ad/0x1f0
[ 259.549471] ret_from_fork+0x2d/0x50
[ 259.549965] ret_from_fork_asm+0x11/0x20

[ 259.550727] Second to last potentially related work creation:
[ 259.551493] kasan_save_stack+0x21/0x40
[ 259.552017] __kasan_record_aux_stack+0x94/0xa0
[ 259.552609] __call_rcu_common.constprop.0+0x47/0x620
[ 259.553263] wait_consider_task+0xad9/0x1a50
[ 259.553868] do_wait+0x3b7/0x530
[ 259.554351] kernel_wait4+0xf0/0x1c0
[ 259.554841] __do_sys_wait4+0xf5/0x100
[ 259.555417] do_syscall_64+0x35/0x80
[ 259.555978] entry_SYSCALL_64_after_hwframe+0x46/0xb0

[ 259.556927] The buggy address belongs to the object at ffff88800859dc40
which belongs to the cache task_struct of size 7616
[ 259.558500] The buggy address is located 176 bytes inside of
freed 7616-byte region [ffff88800859dc40, ffff88800859fa00)

[ 259.560279] The buggy address belongs to the physical page:
[ 259.561018] page:ffffea0000216600 refcount:1 mapcount:0
mapping:0000000000000000 index:0x0 pfn:0x8598
[ 259.562223] head:ffffea0000216600 order:3 entire_mapcount:0
nr_pages_mapped:0 pincount:0
[ 259.563253] memcg:ffff8880061adcc1
[ 259.563701] flags: 0x100000000000840(slab|head|node=0|zone=1)
[ 259.564489] page_type: 0xffffffff()
[ 259.564968] raw: 0100000000000840 ffff888001270500 ffffea0000132000
dead000000000002
[ 259.565986] raw: 0000000000000000 0000000080040004 00000001ffffffff
ffff8880061adcc1
[ 259.566960] page dumped because: kasan: bad access detected

[ 259.567919] Memory state around the buggy address:
[ 259.568556] ffff88800859db80: fc fc fc fc fc fc fc fc fc fc fc fc
fc fc fc fc
[ 259.569494] ffff88800859dc00: fc fc fc fc fc fc fc fc fa fb fb fb
fb fb fb fb
[ 259.570401] >ffff88800859dc80: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[ 259.571290] ^
[ 259.572200] ffff88800859dd00: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[ 259.573044] ffff88800859dd80: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[ 259.574019] ==================================================================
[ 259.575110] Disabling lock debugging due to kernel taint

And the second hit:

[ 36.796236] TCP: AO key not found for (10.0.1.1,
35779)->(10.0.254.1, 7018) S keyid: 100 L3index: 0
[ 37.869018] ==================================================================
[ 37.870095] BUG: KASAN: slab-use-after-free in reweight_entity+0x3b0/0x490
[ 37.870728] Read of size 8 at addr ffff88800fd51f70 by task
unsigned-md5_ip/1488

[ 37.871569] CPU: 1 PID: 1488 Comm: unsigned-md5_ip Not tainted 6.6.0-rc6+ #10
[ 37.872272] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
BIOS Arch Linux 1.16.2-2-2 04/01/2014
[ 37.873054] Call Trace:
[ 37.873275] <IRQ>
[ 37.873455] dump_stack_lvl+0x46/0x70
[ 37.873780] print_report+0xc5/0x610
[ 37.874147] ? __virt_addr_valid+0xbe/0x130
[ 37.874544] kasan_report+0xbe/0xf0
[ 37.874870] ? reweight_entity+0x3b0/0x490
[ 37.875240] ? reweight_entity+0x3b0/0x490
[ 37.875588] reweight_entity+0x3b0/0x490
[ 37.875923] task_tick_fair+0x8e/0x3e0
[ 37.876257] ? lock_is_held_type+0xbf/0x110
[ 37.876621] scheduler_tick+0xef/0x210
[ 37.876944] update_process_times+0xb9/0xd0
[ 37.877314] tick_sched_handle+0x37/0x90
[ 37.877660] tick_sched_timer+0x84/0xa0
[ 37.877989] ? tick_sched_do_timer+0x100/0x100
[ 37.878437] __hrtimer_run_queues+0x35e/0x600
[ 37.878828] ? enqueue_hrtimer+0x140/0x140
[ 37.879254] ? kvm_clock_get_cycles+0x14/0x30
[ 37.879652] ? ktime_get_update_offsets_now+0xd9/0x1d0
[ 37.880146] hrtimer_interrupt+0x1b4/0x360
[ 37.880506] __sysvec_apic_timer_interrupt+0xb7/0x280
[ 37.880941] sysvec_apic_timer_interrupt+0x85/0xb0
[ 37.881379] </IRQ>
[ 37.881565] <TASK>
[ 37.881751] asm_sysvec_apic_timer_interrupt+0x16/0x20
[ 37.882204] RIP: 0010:insert_header+0x3cf/0x8a0
[ 37.882600] Code: 8b 7c 24 20 e8 32 17 ec ff 49 c7 47 38 00 00 00
00 48 89 df e8 12 fa ff ff 48 83 c4 60 89 e8 5b 5d 41 5c 41 5d 41 5e
41 5f c3 <48> 8d 6b 10 e9 f4 fd ff ff 31 db 4c 89 ef e8 fe 16 ec ff 49
89 5d
[ 37.884196] RSP: 0018:ffffc9000114f240 EFLAGS: 00000286
[ 37.884656] RAX: 00000000ffffffff RBX: ffff88800fd72590 RCX: ffffffff8e5cb5f1
[ 37.885266] RDX: 1ffffffff1db04b4 RSI: 0000000000000008 RDI: ffffffff8ed825a1
[ 37.885857] RBP: 000000000000000d R08: 0000000000000000 R09: fffffbfff1db04b4
[ 37.886475] R10: ffffffff8ed825a7 R11: 0000000000000001 R12: 0000000000000013
[ 37.887087] R13: ffff88800fd72690 R14: ffffffff8ed827a0 R15: ffffffff8ed825a0
[ 37.887681] ? memcmp+0x41/0xa0
[ 37.887972] __register_sysctl_table+0x57d/0xac0
[ 37.888378] ? proc_sys_evict_inode+0xa0/0xa0
[ 37.888751] ? rcu_is_watching+0x34/0x50
[ 37.889134] ? register_net_sysctl_sz+0xef/0x200
[ 37.889531] __addrconf_sysctl_register+0x16f/0x270
[ 37.889954] ? inet6_netconf_notify_devconf+0x100/0x100
[ 37.890408] ? lockdep_init_map_type+0xe8/0x390
[ 37.890798] addrconf_sysctl_register+0xa5/0xd0
[ 37.891213] ipv6_add_dev+0x4d5/0x890
[ 37.891537] addrconf_notify+0x21a/0xad0
[ 37.891876] ? cfg80211_netdev_notifier_call+0x31/0x750
[ 37.892336] ? lockdep_rtnl_is_held+0x16/0x20
[ 37.892732] notifier_call_chain+0x56/0x180
[ 37.893130] register_netdevice+0x83d/0x960
[ 37.893487] ? unregister_netdevice_queue+0x1e0/0x1e0
[ 37.893911] ? alloc_netdev_mqs+0x78a/0x800
[ 37.894318] vrf_newlink+0x8b/0x4f0
[ 37.894654] __rtnl_newlink+0x7ea/0xc90
[ 37.895011] ? rtnl_setlink+0x250/0x250
[ 37.895351] ? reacquire_held_locks+0x280/0x280
[ 37.895753] ? kasan_unpoison+0x40/0x60
[ 37.896112] ? rtnl_newlink+0x36/0x70
[ 37.896439] rtnl_newlink+0x4f/0x70
[ 37.896749] rtnetlink_rcv_msg+0x1f8/0x650
[ 37.897263] ? rtnl_getlink+0x590/0x590
[ 37.897616] ? lockdep_hardirqs_on_prepare+0x220/0x220
[ 37.898089] ? find_held_lock+0x8a/0xa0
[ 37.898462] ? local_clock_noinstr+0x9/0xb0
[ 37.898896] netlink_rcv_skb+0xdd/0x210
[ 37.899709] ? rtnl_getlink+0x590/0x590
[ 37.900112] ? netlink_ack+0x840/0x840
[ 37.900468] ? lock_sync+0x100/0x100
[ 37.900784] ? __rcu_read_unlock+0x6b/0x2a0
[ 37.901198] ? netlink_deliver_tap+0xfe/0x620
[ 37.901583] netlink_unicast+0x2f3/0x480
[ 37.901926] ? netlink_attachskb+0x440/0x440
[ 37.902318] netlink_sendmsg+0x3c0/0x6e0
[ 37.902662] ? netlink_unicast+0x480/0x480
[ 37.903037] ? netlink_unicast+0x480/0x480
[ 37.903396] __sock_sendmsg+0x73/0xc0
[ 37.903725] __sys_sendto+0x18b/0x210
[ 37.904084] ? __ia32_sys_getpeername+0x50/0x50
[ 37.904521] ? mark_held_locks+0x1a/0x80
[ 37.904892] __x64_sys_sendto+0x72/0x80
[ 37.905257] do_syscall_64+0x35/0x80
[ 37.905584] entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 37.906053] RIP: 0033:0x7fb3d69e69ec
[ 37.906379] Code: 89 4c 24 1c e8 a5 63 f7 ff 44 8b 54 24 1c 8b 3c
24 45 31 c9 89 c5 48 8b 54 24 10 48 8b 74 24 08 45 31 c0 b8 2c 00 00
00 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 04 24 e8 f1 63 f7 ff 48
8b 04
[ 37.907987] RSP: 002b:00007fff52147f60 EFLAGS: 00000246 ORIG_RAX:
000000000000002c
[ 37.908695] RAX: ffffffffffffffda RBX: 00007fff52147fa0 RCX: 00007fb3d69e69ec
[ 37.909335] RDX: 0000000000000044 RSI: 00007fff52147fa0 RDI: 0000000000000006
[ 37.909978] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[ 37.910597] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000038
[ 37.911224] R13: 0000000000000006 R14: 00007fff52147fcc R15: 00007fff52147fd8
[ 37.911894] </TASK>

[ 37.912609] Allocated by task 817:
[ 37.913277] kasan_save_stack+0x21/0x40
[ 37.913712] kasan_set_track+0x21/0x30
[ 37.914070] __kasan_slab_alloc+0x62/0x70
[ 37.914436] kmem_cache_alloc_node+0x187/0x370
[ 37.914835] copy_process+0x2c4/0x3460
[ 37.915187] kernel_clone+0xf6/0x570
[ 37.915502] user_mode_thread+0xab/0xe0
[ 37.915837] call_usermodehelper_exec_work+0x78/0xb0
[ 37.916288] process_one_work+0x439/0x8d0
[ 37.916652] worker_thread+0x393/0x680
[ 37.917001] kthread+0x1ad/0x1f0
[ 37.917343] ret_from_fork+0x2d/0x50
[ 37.917673] ret_from_fork_asm+0x11/0x20

[ 37.918208] Freed by task 0:
[ 37.918471] kasan_save_stack+0x21/0x40
[ 37.918833] kasan_set_track+0x21/0x30
[ 37.919192] kasan_save_free_info+0x27/0x40
[ 37.919576] __kasan_slab_free+0x106/0x180
[ 37.919967] kmem_cache_free+0x1d4/0x460
[ 37.920337] delayed_put_task_struct+0x131/0x170
[ 37.920762] rcu_core+0x63d/0x1470
[ 37.921113] __do_softirq+0x10f/0x51b

[ 37.921613] Last potentially related work creation:
[ 37.922097] kasan_save_stack+0x21/0x40
[ 37.922460] __kasan_record_aux_stack+0x94/0xa0
[ 37.922875] __call_rcu_common.constprop.0+0x47/0x620
[ 37.923353] __schedule+0x74c/0x1490
[ 37.923685] schedule+0x81/0xe0
[ 37.923989] schedule_timeout+0x138/0x2a0
[ 37.924365] rcu_gp_fqs_loop+0x1c0/0x990
[ 37.924737] rcu_gp_kthread+0x307/0x3a0
[ 37.925112] kthread+0x1ad/0x1f0
[ 37.925416] ret_from_fork+0x2d/0x50
[ 37.925753] ret_from_fork_asm+0x11/0x20

[ 37.926280] The buggy address belongs to the object at ffff88800fd51ec0
which belongs to the cache task_struct of size 7616
[ 37.927547] The buggy address is located 176 bytes inside of
freed 7616-byte region [ffff88800fd51ec0, ffff88800fd53c80)

[ 37.928923] The buggy address belongs to the physical page:
[ 37.929463] page:ffffea00003f5400 refcount:1 mapcount:0
mapping:0000000000000000 index:0x0 pfn:0xfd50
[ 37.930370] head:ffffea00003f5400 order:3 entire_mapcount:0
nr_pages_mapped:0 pincount:0
[ 37.931313] memcg:ffff888006cc0f41
[ 37.931735] flags: 0x100000000000840(slab|head|node=0|zone=1)
[ 37.932434] page_type: 0xffffffff()
[ 37.932787] raw: 0100000000000840 ffff888001270500 dead000000000122
0000000000000000
[ 37.933502] raw: 0000000000000000 0000000080040004 00000001ffffffff
ffff888006cc0f41
[ 37.934220] page dumped because: kasan: bad access detected

[ 37.934911] Memory state around the buggy address:
[ 37.935377] ffff88800fd51e00: fc fc fc fc fc fc fc fc fc fc fc fc
fc fc fc fc
[ 37.936063] ffff88800fd51e80: fc fc fc fc fc fc fc fc fa fb fb fb
fb fb fb fb
[ 37.936729] >ffff88800fd51f00: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[ 37.937445] ^
[ 37.938101] ffff88800fd51f80: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[ 37.938817] ffff88800fd52000: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[ 37.939655] ==================================================================
[ 37.940196] Disabling lock debugging due to kernel taint

--
Dmitry