================================================================== 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+0x33/0x40 kernel/locking/spinlock.c:178 Read of size 1 at addr ffff88803397a758 by task kworker/u8:4/59 CPU: 0 UID: 0 PID: 59 Comm: kworker/u8:4 Not tainted 6.16.0-rc4-syzkaller-00123-g4c06e63b9203 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: kkcmd kcm_tx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xcd/0x680 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 __kasan_check_byte+0x36/0x50 mm/kasan/common.c:557 kasan_check_byte include/linux/kasan.h:399 [inline] lock_acquire kernel/locking/lockdep.c:5845 [inline] lock_acquire+0xfc/0x350 kernel/locking/lockdep.c:5828 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] __lock_sock+0x146/0x260 net/core/sock.c:3190 lock_sock_nested+0xda/0xf0 net/core/sock.c:3757 lock_sock include/net/sock.h:1667 [inline] kcm_tx_work+0x25/0x1e0 net/kcm/kcmsock.c:717 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 12743: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x89/0x90 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+0x1cb/0x3b0 mm/slub.c:4204 sk_prot_alloc+0x60/0x2a0 net/core/sock.c:2241 sk_alloc+0x36/0xc20 net/core/sock.c:2303 kcm_clone net/kcm/kcmsock.c:1519 [inline] kcm_ioctl+0x5d9/0x1220 net/kcm/kcmsock.c:1564 sock_do_ioctl+0x115/0x280 net/socket.c:1190 sock_ioctl+0x227/0x6b0 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 12750: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 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+0x2d1/0x4d0 mm/slub.c:4745 sk_prot_free net/core/sock.c:2284 [inline] __sk_destruct+0x5b3/0x980 net/core/sock.c:2381 sk_destruct+0xc2/0xf0 net/core/sock.c:2409 __sk_free+0xf4/0x3e0 net/core/sock.c:2420 sk_free+0x6a/0x90 net/core/sock.c:2431 sock_put include/net/sock.h:1960 [inline] kcm_done+0x423/0x16c0 net/kcm/kcmsock.c:1662 kcm_release+0x40d/0x760 net/kcm/kcmsock.c:1731 __sock_release+0xb0/0x270 net/socket.c:647 sock_close+0x1c/0x30 net/socket.c:1391 __fput+0x402/0xb70 fs/file_table.c:465 fput_close_sync+0x118/0x260 fs/file_table.c:570 __do_sys_close fs/open.c:1589 [inline] __se_sys_close fs/open.c:1574 [inline] __x64_sys_close+0x8b/0x120 fs/open.c:1574 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:548 insert_work+0x36/0x230 kernel/workqueue.c:2183 __queue_work+0x97e/0x10f0 kernel/workqueue.c:2341 queue_work_on+0x1a4/0x1f0 kernel/workqueue.c:2392 queue_work include/linux/workqueue.h:662 [inline] kcm_unattach+0xb63/0x1330 net/kcm/kcmsock.c:1428 kcm_unattach_ioctl net/kcm/kcmsock.c:1485 [inline] kcm_ioctl+0x9c6/0x1220 net/kcm/kcmsock.c:1552 sock_do_ioctl+0x115/0x280 net/socket.c:1190 sock_ioctl+0x227/0x6b0 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Second to last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:548 insert_work+0x36/0x230 kernel/workqueue.c:2183 __queue_work+0x97e/0x10f0 kernel/workqueue.c:2341 queue_work_on+0x1a4/0x1f0 kernel/workqueue.c:2392 queue_work include/linux/workqueue.h:662 [inline] psock_now_avail+0x249/0x420 net/kcm/kcmsock.c:519 kcm_attach net/kcm/kcmsock.c:1308 [inline] kcm_attach_ioctl net/kcm/kcmsock.c:1336 [inline] kcm_ioctl+0xefd/0x1220 net/kcm/kcmsock.c:1542 sock_do_ioctl+0x115/0x280 net/socket.c:1190 sock_ioctl+0x227/0x6b0 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803397a580 which belongs to the cache KCM of size 1792 The buggy address is located 472 bytes inside of freed 1792-byte region [ffff88803397a580, ffff88803397ac80) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888033978780 pfn:0x33978 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff8880222e5301 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff888031451640 dead000000000122 0000000000000000 raw: ffff888033978780 000000008011000d 00000000f5000000 ffff8880222e5301 head: 00fff00000000040 ffff888031451640 dead000000000122 0000000000000000 head: ffff888033978780 000000008011000d 00000000f5000000 ffff8880222e5301 head: 00fff00000000003 ffffea0000ce5e01 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 6718, tgid 6712 (syz.1.204), ts 129893229615, free_ts 129892269550 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab mm/slub.c:2619 [inline] new_slab+0x23b/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949 __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] kmem_cache_alloc_noprof+0xef/0x3b0 mm/slub.c:4204 sk_prot_alloc+0x60/0x2a0 net/core/sock.c:2241 sk_alloc+0x36/0xc20 net/core/sock.c:2303 kcm_create+0xfc/0x690 net/kcm/kcmsock.c:1801 __sock_create+0x338/0x8d0 net/socket.c:1541 sock_create net/socket.c:1599 [inline] __sys_socket_create net/socket.c:1636 [inline] __sys_socket+0x14d/0x260 net/socket.c:1683 __do_sys_socket net/socket.c:1697 [inline] __se_sys_socket net/socket.c:1695 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1695 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 6718 tgid 6712 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 __folio_put+0x329/0x450 mm/swap.c:112 bpf_check+0x90c/0xbc50 kernel/bpf/verifier.c:24199 bpf_prog_load+0xe41/0x2490 kernel/bpf/syscall.c:2972 __sys_bpf+0x433c/0x4d80 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+0x78/0xc0 kernel/bpf/syscall.c:5941 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88803397a600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803397a680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803397a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803397a780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803397a800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================