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* [syzbot] [mm?] KASAN: invalid-free in rcu_free_sheaf
@ 2026-06-12 20:43 syzbot
  2026-10-17 11:54 ` syzbot
  0 siblings, 1 reply; 2+ messages in thread
From: syzbot @ 2026-06-12 20:43 UTC (permalink / raw)
  To: linux-kernel, linux-mm, netdev, peterz, syzkaller-bugs, tglx

Hello,

syzbot found the following issue on:

HEAD commit:    0ce346bf2f68 Merge branch 'net-shaper-follow-ups-to-recent..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15a50986580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2c40e3284434c6f1
dashboard link: https://syzkaller.appspot.com/bug?extid=60332fd095f8bb2946ad
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/fcb2184c91a0/disk-0ce346bf.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/44a7baa2dfdd/vmlinux-0ce346bf.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8ef85b3aefe3/bzImage-0ce346bf.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+60332fd095f8bb2946ad@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: double-free in rcu_free_sheaf+0x31/0x200 mm/slub.c:5850
Free of addr ffff888026c2d380 by task ksoftirqd/0/15

CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report_invalid_free+0xea/0x110 mm/kasan/report.c:557
 check_slab_allocation mm/kasan/common.c:-1 [inline]
 __kasan_slab_pre_free+0x104/0x120 mm/kasan/common.c:261
 kasan_slab_pre_free include/linux/kasan.h:199 [inline]
 slab_free_hook mm/slub.c:2634 [inline]
 __rcu_free_sheaf_prepare+0x10a/0x2a0 mm/slub.c:2940
 rcu_free_sheaf+0x31/0x200 mm/slub.c:5850
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
 handle_softirqs+0x22a/0x840 kernel/softirq.c:622
 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 5613:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5420
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 hwsim_update_pib+0x88/0x450 drivers/net/ieee802154/mac802154_hwsim.c:101
 hwsim_set_promiscuous_mode+0x196/0x2e0 drivers/net/ieee802154/mac802154_hwsim.c:323
 drv_set_promiscuous_mode+0x159/0x2e0 net/mac802154/driver-ops.h:127
 drv_start net/mac802154/driver-ops.h:195 [inline]
 mac802154_slave_open net/mac802154/iface.c:196 [inline]
 mac802154_wpan_open+0x19b3/0x2a70 net/mac802154/iface.c:295
 __dev_open+0x44d/0x830 net/core/dev.c:1702
 __dev_change_flags+0x2fa/0x7e0 net/core/dev.c:9752
 netif_change_flags+0x88/0x1a0 net/core/dev.c:9815
 do_setlink+0xfa5/0x45a0 net/core/rtnetlink.c:3207
 rtnl_changelink net/core/rtnetlink.c:3841 [inline]
 __rtnl_newlink net/core/rtnetlink.c:4014 [inline]
 rtnl_newlink+0x15ad/0x1bb0 net/core/rtnetlink.c:4151
 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:7068
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2556
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 __sys_sendto+0x672/0x710 net/socket.c:2265
 __do_sys_sendto net/socket.c:2272 [inline]
 __se_sys_sendto net/socket.c:2268 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2268
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 15:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 __rcu_free_sheaf_prepare+0x12d/0x2a0 mm/slub.c:2940
 rcu_free_sheaf+0x31/0x200 mm/slub.c:5850
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
 handle_softirqs+0x22a/0x840 kernel/softirq.c:622
 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff888026c2d380
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 0 bytes inside of
 64-byte region [ffff888026c2d380, ffff888026c2d3c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888026c2d780 pfn:0x26c2d
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff88813fe1a8c0 ffffea0000d74490 ffffea0001fcda50
raw: ffff888026c2d780 0000000800200010 00000000f5000000 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 137, tgid 137 (kworker/u8:5), ts 5542876120, free_ts 5542851482
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853
 prep_new_page mm/page_alloc.c:1861 [inline]
 get_page_from_freelist+0x2593/0x2610 mm/page_alloc.c:3941
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x339/0x3d0 mm/slub.c:7272
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4652
 alloc_from_pcs mm/slub.c:4750 [inline]
 slab_alloc_node mm/slub.c:4884 [inline]
 __do_kmalloc_node mm/slub.c:5295 [inline]
 __kmalloc_node_noprof+0x577/0x7c0 mm/slub.c:5302
 kmalloc_node_noprof include/linux/slab.h:1081 [inline]
 __vmalloc_area_node mm/vmalloc.c:3857 [inline]
 __vmalloc_node_range_noprof+0x5ef/0x1750 mm/vmalloc.c:4064
 __vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4124
 alloc_thread_stack_node kernel/fork.c:357 [inline]
 dup_task_struct+0x298/0x840 kernel/fork.c:926
 copy_process+0x89b/0x4440 kernel/fork.c:2090
 kernel_clone+0x2d7/0x940 kernel/fork.c:2722
 user_mode_thread+0x110/0x180 kernel/fork.c:2798
 call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
page last free pid 137 tgid 137 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1397 [inline]
 __free_frozen_pages+0xc1c/0xd30 mm/page_alloc.c:2938
 __kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
 __kasan_populate_vmalloc+0x1b2/0x1d0 mm/kasan/shadow.c:424
 kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
 alloc_vmap_area+0xd47/0x1480 mm/vmalloc.c:2123
 __get_vm_area_node+0x1f8/0x300 mm/vmalloc.c:3226
 __vmalloc_node_range_noprof+0x36a/0x1750 mm/vmalloc.c:4024
 __vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4124
 alloc_thread_stack_node kernel/fork.c:357 [inline]
 dup_task_struct+0x298/0x840 kernel/fork.c:926
 copy_process+0x89b/0x4440 kernel/fork.c:2090
 kernel_clone+0x2d7/0x940 kernel/fork.c:2722
 user_mode_thread+0x110/0x180 kernel/fork.c:2798
 call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff888026c2d280: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888026c2d300: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888026c2d380: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff888026c2d400: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888026c2d480: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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If the report is already addressed, let syzbot know by replying with:
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If you want to overwrite report's subsystems, reply with:
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(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [syzbot] [mm?] KASAN: invalid-free in rcu_free_sheaf
  2026-06-12 20:43 [syzbot] [mm?] KASAN: invalid-free in rcu_free_sheaf syzbot
@ 2026-10-17 11:54 ` syzbot
  0 siblings, 0 replies; 2+ messages in thread
From: syzbot @ 2026-10-17 11:54 UTC (permalink / raw)
  To: alex.aring, alhouseenyousef, andrew, davem, devnexen, edumazet,
	gregkh, kuba, linux-kernel, linux-mm, linux-wpan, malayarout91,
	miquel.raynal, netdev, pabeni, patches, peterz, sashal,
	stable-commits, stable, stefan, syzkaller-bugs, tglx

syzbot has found a reproducer for the following issue on:

HEAD commit:    00accbd9d502 calipso: update payload_len when removing the..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git
console output: https://syzkaller.appspot.com/x/log.txt?x=159a8121580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c4b098695335c89f
dashboard link: https://syzkaller.appspot.com/bug?extid=60332fd095f8bb2946ad
compiler:       Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1599960d580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+60332fd095f8bb2946ad@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: double-free in rcu_free_sheaf+0x31/0x200 mm/slub.c:6061
Free of addr ffff88803149d500 by task swapper/0/0

CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report_invalid_free+0xea/0x110 mm/kasan/report.c:557
 check_slab_allocation mm/kasan/common.c:-1 [inline]
 __kasan_slab_pre_free+0x104/0x120 mm/kasan/common.c:272
 kasan_slab_pre_free include/linux/kasan.h:199 [inline]
 slab_free_hook mm/slub.c:2693 [inline]
 __rcu_free_sheaf_prepare+0x10a/0x2a0 mm/slub.c:3009
 rcu_free_sheaf+0x31/0x200 mm/slub.c:6061
 rcu_do_batch kernel/rcu/tree.c:2650 [inline]
 rcu_core+0x926/0x1260 kernel/rcu/tree.c:2919
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 0b 8b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 c5 20 00 fb f4 <e9> 8c 08 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8fa07ca0 EFLAGS: 00000246
RAX: 00000000000a9303 RBX: ffffffff819bed20 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e469bdf RDI: ffffffff8c6ddb80
RBP: ffffffff8fa07d78 R08: ffff8880b8433a1b R09: 1ffff11017086743
R10: dffffc0000000000 R11: ffffed1017086744 R12: 0000000000000000
R13: 1ffffffff1f51e00 R14: 1ffffffff1f40f9c R15: dffffc0000000000
 arch_safe_halt arch/x86/kernel/process.c:767 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:768
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x2e0/0x540 kernel/sched/idle.c:355
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
 rest_init+0x378/0x3a0 init/main.c:732
 start_kernel+0x392/0x3e0 init/main.c:1190
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x157
 </TASK>

Allocated by task 977:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x321/0x600 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 hwsim_update_pib+0x7e/0x400 drivers/net/ieee802154/mac802154_hwsim.c:103
 hwsim_set_promiscuous_mode+0x196/0x2e0 drivers/net/ieee802154/mac802154_hwsim.c:326
 drv_set_promiscuous_mode+0x159/0x2e0 net/mac802154/driver-ops.h:127
 drv_start+0x4ea/0x1010 net/mac802154/driver-ops.h:167
 mac802154_scan_worker+0x8e6/0xe60 net/mac802154/scan.c:248
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 0:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 __rcu_free_sheaf_prepare+0x12d/0x2a0 mm/slub.c:3009
 rcu_free_sheaf+0x31/0x200 mm/slub.c:6061
 rcu_do_batch kernel/rcu/tree.c:2650 [inline]
 rcu_core+0x926/0x1260 kernel/rcu/tree.c:2919
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674

The buggy address belongs to the object at ffff88803149d500
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 0 bytes inside of
 64-byte region [ffff88803149d500, ffff88803149d540)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3149d
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801c0418c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 977, tgid 977 (kworker/u8:7), ts 26471963378
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab+0x7d/0x620 mm/slub.c:3462
 new_slab mm/slub.c:3513 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7418
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __do_kmalloc_node mm/slub.c:5413 [inline]
 __kmalloc_node_noprof+0x54d/0x720 mm/slub.c:5426
 _kmalloc_node_noprof include/linux/slab.h:1200 [inline]
 __vmalloc_area_node mm/vmalloc.c:3893 [inline]
 __vmalloc_node_range_noprof+0x5b4/0x1540 mm/vmalloc.c:4104
 __vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4165
 alloc_thread_stack_node kernel/fork.c:359 [inline]
 dup_task_struct+0x2c6/0xa00 kernel/fork.c:930
 copy_process+0x7e0/0x4400 kernel/fork.c:2134
 kernel_clone+0x2d7/0x940 kernel/fork.c:2771
 user_mode_thread+0x115/0x180 kernel/fork.c:2848
 call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:169
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88803149d400: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
 ffff88803149d480: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff88803149d500: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff88803149d580: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
 ffff88803149d600: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	0b 8b 02 c3 cc cc    	or     -0x33333cfe(%rbx),%ecx
   6:	cc                   	int3
   7:	cc                   	int3
   8:	cc                   	int3
   9:	cc                   	int3
   a:	cc                   	int3
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	f3 0f 1e fa          	endbr64
  1f:	66 90                	xchg   %ax,%ax
  21:	0f 00 2d 33 c5 20 00 	verw   0x20c533(%rip)        # 0x20c55b
  28:	fb                   	sti
  29:	f4                   	hlt
* 2a:	e9 8c 08 03 00       	jmp    0x308bb <-- trapping instruction
  2f:	cc                   	int3
  30:	cc                   	int3
  31:	cc                   	int3
  32:	cc                   	int3
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	cc                   	int3
  38:	cc                   	int3
  39:	cc                   	int3
  3a:	cc                   	int3
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop


---
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#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

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