==================================================================
BUG: KASAN: slab-use-after-free in flush_tlb_func+0x24d/0x560
Write of size 8 at addr ffff88803e86db80 by task syz-executor.5/5553

CPU: 0 UID: 0 PID: 5553 Comm: syz-executor.5 Not tainted 6.16.0-rc4-next-20250630 #1 PREEMPT(voluntary) 
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 <IRQ>
 dump_stack_lvl+0xca/0x120
 print_report+0xcb/0x670
 kasan_report+0xca/0x100
 kasan_check_range+0x39/0x1b0
 flush_tlb_func+0x24d/0x560
 __flush_smp_call_function_queue+0x20d/0x740
 __sysvec_call_function_single+0x6d/0x360
 sysvec_call_function_single+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_call_function_single+0x1a/0x20
RIP: 0010:generic_exec_single+0x1dd/0x2c0
Code: e8 e8 82 13 00 31 f6 48 89 ef e8 be d7 ff ff 4c 89 ef e8 c6 5e 52 03 31 f6 48 89 ef e8 4c d9 ff ff e8 27 81 13 00 fb 45 31 e4 <e9> ae fe ff ff e8 09 57 0b 00 90 0f 0b 90 e9 45 ff ff ff 4c 89 f7
RSP: 0018:ffff88802fbafbb0 EFLAGS: 00000246
RAX: 0000000000000077 RBX: 0000000000000200 RCX: 0000000000000040
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff81683f69
RBP: ffffffff81845700 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff86438657 R11: 0000000000000001 R12: 0000000000000000
R13: ffff88802fbafce8 R14: ffff88802fbafc28 R15: 0000000000000000
 smp_call_function_single+0x327/0x420
 perf_install_in_context+0x4c3/0x570
 __do_sys_perf_event_open+0x19a6/0x2c60
 do_syscall_64+0xbf/0x360
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd997a88b19
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd994ffe188 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fd997b9bf60 RCX: 00007fd997a88b19
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000020000080
RBP: 00007fd997ae2f6d R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeaa0de67f R14: 00007fd994ffe300 R15: 0000000000022000
 </TASK>

Allocated by task 283:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 __kasan_slab_alloc+0x59/0x70
 kmem_cache_alloc_noprof+0x13c/0x470
 copy_process+0x6f3a/0x73e0
 kernel_clone+0xea/0x820
 __do_sys_clone+0xce/0x120
 do_syscall_64+0xbf/0x360
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5549:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 kasan_save_free_info+0x3a/0x60
 __kasan_slab_free+0x38/0x50
 kmem_cache_free+0x2a1/0x460
 mmput+0x305/0x390
 do_exit+0x79d/0x2970
 do_group_exit+0xd3/0x2a0
 get_signal+0x2315/0x2340
 arch_do_signal_or_restart+0x80/0x790
 exit_to_user_mode_loop+0x8b/0x100
 do_syscall_64+0x2f7/0x360
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88803e86d200
 which belongs to the cache mm_struct of size 2456
The buggy address is located 2432 bytes inside of
 freed 2456-byte region [ffff88803e86d200, ffff88803e86db98)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3e868
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88800b804f81
flags: 0x100000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0100000000000040 ffff888008c4bc80 ffffea0000572600 dead000000000002
raw: 0000000000000000 00000000800c000c 00000000f5000000 ffff88800b804f81
head: 0100000000000040 ffff888008c4bc80 ffffea0000572600 dead000000000002
head: 0000000000000000 00000000800c000c 00000000f5000000 ffff88800b804f81
head: 0100000000000003 ffffea0000fa1a01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88803e86da80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803e86db00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88803e86db80: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff88803e86dc00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff88803e86dc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
loop6: detected capacity change from 0 to 256
loop2: detected capacity change from 0 to 256
loop6: detected capacity change from 0 to 256
loop4: detected capacity change from 0 to 256
loop2: detected capacity change from 0 to 256
loop4: detected capacity change from 0 to 256
loop4: detected capacity change from 0 to 256
loop2: detected capacity change from 0 to 256
----------------
Code disassembly (best guess):
   0:	e8 e8 82 13 00       	callq  0x1382ed
   5:	31 f6                	xor    %esi,%esi
   7:	48 89 ef             	mov    %rbp,%rdi
   a:	e8 be d7 ff ff       	callq  0xffffd7cd
   f:	4c 89 ef             	mov    %r13,%rdi
  12:	e8 c6 5e 52 03       	callq  0x3525edd
  17:	31 f6                	xor    %esi,%esi
  19:	48 89 ef             	mov    %rbp,%rdi
  1c:	e8 4c d9 ff ff       	callq  0xffffd96d
  21:	e8 27 81 13 00       	callq  0x13814d
  26:	fb                   	sti
  27:	45 31 e4             	xor    %r12d,%r12d
* 2a:	e9 ae fe ff ff       	jmpq   0xfffffedd <-- trapping instruction
  2f:	e8 09 57 0b 00       	callq  0xb573d
  34:	90                   	nop
  35:	0f 0b                	ud2
  37:	90                   	nop
  38:	e9 45 ff ff ff       	jmpq   0xffffff82
  3d:	4c 89 f7             	mov    %r14,%rdi