==================================================================
BUG: KASAN: slab-use-after-free in __lock_acquire+0x91/0xba0 kernel/locking/lockdep.c:5009
Read of size 8 at addr ffff888173802c38 by task kworker/u4:10/1277

CPU: 1 PID: 1277 Comm: kworker/u4:10 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: kkcmd kcm_tx_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe0/0x160 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xac/0x220 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 __lock_acquire+0x91/0xba0 kernel/locking/lockdep.c:5009
 lock_acquire+0x171/0x350 kernel/locking/lockdep.c:5754
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 lock_sock_nested+0x4f/0xd0 net/core/sock.c:3538
 lock_sock include/net/sock.h:1767 [inline]
 kcm_tx_work+0x2c/0x140 net/kcm/kcmsock.c:716
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0x92b/0x11f0 kernel/workqueue.c:2711
 worker_thread+0x856/0xc80 kernel/workqueue.c:2792
 kthread+0x229/0x280 kernel/kthread.c:388
 ret_from_fork+0x2f/0x60 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Allocated by task 3296:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x66/0x430 mm/slab.h:767
 slab_alloc_node mm/slub.c:3495 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc+0x11e/0x2a0 mm/slub.c:3519
 sk_prot_alloc+0x51/0x1c0 net/core/sock.c:2090
 sk_alloc+0x34/0x830 net/core/sock.c:2152
 kcm_clone net/kcm/kcmsock.c:1518 [inline]
 kcm_ioctl+0x28e/0xe20 net/kcm/kcmsock.c:1563
 sock_do_ioctl+0xd1/0x260 net/socket.c:1222
 sock_ioctl+0x4a7/0x560 net/socket.c:1341
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xad/0x100 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 3297:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 kmem_cache_free+0xe7/0x250 mm/slub.c:3852
 sk_prot_free net/core/sock.c:2133 [inline]
 __sk_destruct+0x38c/0x530 net/core/sock.c:2230
 kcm_release+0x379/0x4f0 net/kcm/kcmsock.c:1738
 __sock_release net/socket.c:659 [inline]
 sock_close+0xb3/0x210 net/socket.c:1421
 __fput+0x1b1/0x790 fs/file_table.c:384
 __do_sys_close fs/open.c:1573 [inline]
 __se_sys_close+0x118/0x170 fs/open.c:1558
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 insert_work+0x37/0x1f0 kernel/workqueue.c:1651
 __queue_work+0x801/0xa50 kernel/workqueue.c:1800
 queue_work_on+0xbe/0x140 kernel/workqueue.c:1835
 queue_work include/linux/workqueue.h:562 [inline]
 kcm_unattach+0x8c2/0xe60 net/kcm/kcmsock.c:1427
 kcm_unattach_ioctl net/kcm/kcmsock.c:1484 [inline]
 kcm_ioctl+0x6d5/0xe20 net/kcm/kcmsock.c:1551
 sock_do_ioctl+0xd1/0x260 net/socket.c:1222
 sock_ioctl+0x4a7/0x560 net/socket.c:1341
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xad/0x100 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Second to last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 insert_work+0x37/0x1f0 kernel/workqueue.c:1651
 __queue_work+0x801/0xa50 kernel/workqueue.c:1800
 queue_work_on+0xbe/0x140 kernel/workqueue.c:1835
 kcm_attach net/kcm/kcmsock.c:1307 [inline]
 kcm_attach_ioctl net/kcm/kcmsock.c:1335 [inline]
 kcm_ioctl+0xc9a/0xe20 net/kcm/kcmsock.c:1541
 sock_do_ioctl+0xd1/0x260 net/socket.c:1222
 sock_ioctl+0x4a7/0x560 net/socket.c:1341
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xad/0x100 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff888173802b80
 which belongs to the cache KCM of size 1720
The buggy address is located 184 bytes inside of
 freed 1720-byte region [ffff888173802b80, ffff888173803238)

The buggy address belongs to the physical page:
page:ffffea0005ce0000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x173800
head:ffffea0005ce0000 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88817774f601
flags: 0x100000000000840(slab|head|node=0|zone=2)
page_type: 0xffffffff()
raw: 0100000000000840 ffff888106b3ea00 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080110011 00000001ffffffff ffff88817774f601
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 3276, tgid 3273 (syz.2.16), ts 76025339353, free_ts 75946438942
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x26b/0x290 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x3447/0x35f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x430 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x70/0x260 mm/slub.c:2081
 ___slab_alloc+0xa3e/0xee0 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc+0x19c/0x2a0 mm/slub.c:3519
 sk_prot_alloc+0x51/0x1c0 net/core/sock.c:2090
 sk_alloc+0x34/0x830 net/core/sock.c:2152
 kcm_clone net/kcm/kcmsock.c:1518 [inline]
 kcm_ioctl+0x28e/0xe20 net/kcm/kcmsock.c:1563
 sock_do_ioctl+0xd1/0x260 net/socket.c:1222
 sock_ioctl+0x4a7/0x560 net/socket.c:1341
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xad/0x100 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7f9/0x910 mm/page_alloc.c:2336
 free_unref_page+0x32/0x290 mm/page_alloc.c:2429
 discard_slab mm/slub.c:2127 [inline]
 __unfreeze_partials+0x1a4/0x1e0 mm/slub.c:2667
 put_cpu_partial+0x14c/0x1b0 mm/slub.c:2743
 __slab_free+0x297/0x380 mm/slub.c:3700
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x66/0x430 mm/slab.h:767
 slab_alloc_node mm/slub.c:3495 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc+0x11e/0x2a0 mm/slub.c:3519
 vm_area_alloc+0x1f/0x190 kernel/fork.c:486
 __mmap_region mm/mmap.c:2770 [inline]
 mmap_region+0xac9/0x1810 mm/mmap.c:2941
 do_mmap+0x710/0xc30 mm/mmap.c:1385
 vm_mmap_pgoff+0x191/0x350 mm/util.c:556
 ksys_mmap_pgoff+0x2c2/0x3b0 mm/mmap.c:1431
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81

Memory state around the buggy address:
 ffff888173802b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888173802b80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888173802c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff888173802c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888173802d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================