================================================================== BUG: KASAN: slab-use-after-free in lock_sock_nested+0x48/0x100 net/core/sock.c:3752 Read of size 1 at addr ffff888028189158 by task kworker/u8:2/36 CPU: 1 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted 6.15.0-syzkaller-ge41079f53e87 #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_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:557 kasan_check_byte include/linux/kasan.h:399 [inline] lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5845 lock_sock_nested+0x48/0x100 net/core/sock.c:3752 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+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 6751: 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+0xdc/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+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6751: 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/0x400 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+0xc3/0x240 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+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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/0x330 kernel/workqueue.c:2183 __queue_work+0xcfc/0xfe0 kernel/workqueue.c:2341 queue_work_on+0x181/0x270 kernel/workqueue.c:2392 queue_work include/linux/workqueue.h:662 [inline] kcm_unattach+0x863/0xe90 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+0xdc/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+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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/0x330 kernel/workqueue.c:2183 __queue_work+0xcfc/0xfe0 kernel/workqueue.c:2341 queue_work_on+0x181/0x270 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+0xdc/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+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888028188f00 which belongs to the cache KCM of size 1792 The buggy address is located 600 bytes inside of freed 1792-byte region [ffff888028188f00, ffff888028189600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888028188780 pfn:0x28188 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888078e3df01 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88802f5f4a00 dead000000000122 0000000000000000 raw: ffff888028188780 000000008011000f 00000000f5000000 ffff888078e3df01 head: 00fff00000000040 ffff88802f5f4a00 dead000000000122 0000000000000000 head: ffff888028188780 000000008011000f 00000000f5000000 ffff888078e3df01 head: 00fff00000000003 ffffea0000a06201 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 5932, tgid 5931 (syz.2.3), ts 105265549389, free_ts 105259261533 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+0x21e4/0x22c0 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/0x3b0 mm/slub.c:2619 new_slab mm/slub.c:2673 [inline] ___slab_alloc+0xbfc/0x1480 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_create+0x100/0x580 net/kcm/kcmsock.c:1801 __sock_create+0x4b3/0x9f0 net/socket.c:1541 sock_create net/socket.c:1599 [inline] __sys_socket_create net/socket.c:1636 [inline] __sys_socket+0xd7/0x1b0 net/socket.c:1683 __do_sys_socket net/socket.c:1697 [inline] __se_sys_socket net/socket.c:1695 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1695 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5932 tgid 5931 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x161/0x1c0 mm/slub.c:3186 put_cpu_partial+0x17c/0x250 mm/slub.c:3261 __slab_free+0x2f7/0x400 mm/slub.c:4513 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 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] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_noprof+0x21b/0x4e0 mm/slub.c:4334 kmalloc_node_noprof include/linux/slab.h:932 [inline] __vmalloc_area_node mm/vmalloc.c:3690 [inline] __vmalloc_node_range_noprof+0x5a9/0x12f0 mm/vmalloc.c:3885 __vmalloc_node_noprof mm/vmalloc.c:3948 [inline] vzalloc_noprof+0xb2/0xf0 mm/vmalloc.c:4022 bpf_check+0x1fb/0x19c60 kernel/bpf/verifier.c:23967 bpf_prog_load+0x1318/0x1930 kernel/bpf/syscall.c:2972 __sys_bpf+0x5f1/0x860 kernel/bpf/syscall.c:5837 __do_sys_bpf kernel/bpf/syscall.c:5944 [inline] __se_sys_bpf kernel/bpf/syscall.c:5942 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5942 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888028189000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888028189080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888028189100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888028189180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888028189200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================