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BUG: KASAN: slab-use-after-free in __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
BUG: KASAN: slab-use-after-free in _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178
Read of size 1 at addr ffff888031519fd8 by task kworker/u8:7/1160

CPU: 0 UID: 0 PID: 1160 Comm: kworker/u8:7 Not tainted 6.16.0-rc6-syzkaller-00121-g6832a9317eee #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: kkcmd kcm_tx_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x230 mm/kasan/report.c:480
 kasan_report+0x118/0x150 mm/kasan/report.c:593
 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:557
 kasan_check_byte include/linux/kasan.h:399 [inline]
 lock_acquire+0x8d/0x350 kernel/locking/lockdep.c:5845
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 __lock_sock+0x156/0x2a0 net/core/sock.c:3190
 lock_sock_nested+0x9f/0x100 net/core/sock.c:3757
 lock_sock include/net/sock.h:1667 [inline]
 kcm_tx_work+0x31/0x180 net/kcm/kcmsock.c:717
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x1790 kernel/workqueue.c:3321
 worker_thread+0xa57/0xfc0 kernel/workqueue.c:3402
 kthread+0x711/0x890 kernel/kthread.c:464
 ret_from_fork+0x3f8/0x760 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 6806:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204
 sk_prot_alloc+0x57/0x220 net/core/sock.c:2241
 sk_alloc+0x3a/0x370 net/core/sock.c:2303
 kcm_clone net/kcm/kcmsock.c:1519 [inline]
 kcm_ioctl+0x214/0xff0 net/kcm/kcmsock.c:1564
 sock_do_ioctl+0xd9/0x300 net/socket.c:1190
 sock_ioctl+0x576/0x790 net/socket.c:1311
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 6807:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kmem_cache_free+0x18f/0x3f0 mm/slub.c:4745
 sk_prot_free net/core/sock.c:2284 [inline]
 __sk_destruct+0x4d2/0x660 net/core/sock.c:2381
 kcm_release+0x528/0x5c0 net/kcm/kcmsock.c:1731
 __sock_release net/socket.c:647 [inline]
 sock_close+0xc0/0x240 net/socket.c:1391
 __fput+0x449/0xa70 fs/file_table.c:465
 fput_close_sync+0x119/0x200 fs/file_table.c:570
 __do_sys_close fs/open.c:1589 [inline]
 __se_sys_close fs/open.c:1574 [inline]
 __x64_sys_close+0x7f/0x110 fs/open.c:1574
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
 insert_work+0x3d/0x320 kernel/workqueue.c:2183
 __queue_work+0xcf6/0xfc0 kernel/workqueue.c:2341
 queue_work_on+0x178/0x260 kernel/workqueue.c:2392
 queue_work include/linux/workqueue.h:662 [inline]
 kcm_unattach+0x863/0xe80 net/kcm/kcmsock.c:1428
 kcm_unattach_ioctl net/kcm/kcmsock.c:1485 [inline]
 kcm_ioctl+0x794/0xff0 net/kcm/kcmsock.c:1552
 sock_do_ioctl+0xd9/0x300 net/socket.c:1190
 sock_ioctl+0x576/0x790 net/socket.c:1311
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Second to last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
 insert_work+0x3d/0x320 kernel/workqueue.c:2183
 __queue_work+0xcf6/0xfc0 kernel/workqueue.c:2341
 queue_work_on+0x178/0x260 kernel/workqueue.c:2392
 kcm_attach net/kcm/kcmsock.c:1308 [inline]
 kcm_attach_ioctl net/kcm/kcmsock.c:1336 [inline]
 kcm_ioctl+0xe52/0xff0 net/kcm/kcmsock.c:1542
 sock_do_ioctl+0xd9/0x300 net/socket.c:1190
 sock_ioctl+0x576/0x790 net/socket.c:1311
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The buggy address belongs to the object at ffff888031519e00
 which belongs to the cache KCM of size 1792
The buggy address is located 472 bytes inside of
 freed 1792-byte region [ffff888031519e00, ffff88803151a500)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x31518
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88802f4b83c0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080110011 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88802f4b83c0 dead000000000122 0000000000000000
head: 0000000000000000 0000000080110011 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000c54601 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
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 6790, tgid 6788 (syz.0.29), ts 144173714199, free_ts 144121687536
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x2b37/0x2ce0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 alloc_slab_page mm/slub.c:2451 [inline]
 allocate_slab+0x8a/0x3a0 mm/slub.c:2619
 new_slab mm/slub.c:2673 [inline]
 ___slab_alloc+0xc48/0x14d0 mm/slub.c:3859
 __slab_alloc mm/slub.c:3949 [inline]
 __slab_alloc_node mm/slub.c:4024 [inline]
 slab_alloc_node mm/slub.c:4185 [inline]
 kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4204
 sk_prot_alloc+0x57/0x220 net/core/sock.c:2241
 sk_alloc+0x3a/0x370 net/core/sock.c:2303
 kcm_clone net/kcm/kcmsock.c:1519 [inline]
 kcm_ioctl+0x214/0xff0 net/kcm/kcmsock.c:1564
 sock_do_ioctl+0xd9/0x300 net/socket.c:1190
 sock_ioctl+0x576/0x790 net/socket.c:1311
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
page last free pid 6789 tgid 6788 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0xc6f/0xe70 mm/page_alloc.c:2706
 __folio_put+0x21b/0x2b0 mm/swap.c:112
 folio_put include/linux/mm.h:1356 [inline]
 free_large_kmalloc+0x143/0x200 mm/slub.c:4768
 bpf_check+0x14765/0x19c00 kernel/bpf/verifier.c:24199
 bpf_prog_load+0x1318/0x1930 kernel/bpf/syscall.c:2972
 __sys_bpf+0x5fe/0x860 kernel/bpf/syscall.c:5836
 __do_sys_bpf kernel/bpf/syscall.c:5943 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5941 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5941
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Memory state around the buggy address:
 ffff888031519e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888031519f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888031519f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff88803151a000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803151a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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