================================================================== BUG: KASAN: slab-use-after-free in l2tp_tunnel_del_work+0xe5/0x330 net/l2tp/l2tp_core.c:1334 Read of size 8 at addr ffff88802c6218b8 by task kworker/u8:0/11 CPU: 0 UID: 0 PID: 11 Comm: kworker/u8:0 Not tainted 6.10.0-rc6-next-20240701-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Workqueue: l2tp l2tp_tunnel_del_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 l2tp_tunnel_del_work+0xe5/0x330 net/l2tp/l2tp_core.c:1334 process_one_work kernel/workqueue.c:3224 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3305 worker_thread+0x86d/0xd40 kernel/workqueue.c:3383 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 6491: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:4158 [inline] __kmalloc_noprof+0x1f9/0x400 mm/slub.c:4171 kmalloc_noprof include/linux/slab.h:664 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] l2tp_session_create+0x3b/0xc20 net/l2tp/l2tp_core.c:1675 pppol2tp_connect+0xca3/0x17a0 net/l2tp/l2tp_ppp.c:782 __sys_connect_file net/socket.c:2061 [inline] __sys_connect+0x2df/0x310 net/socket.c:2078 __do_sys_connect net/socket.c:2088 [inline] __se_sys_connect net/socket.c:2085 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2085 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5095: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2231 [inline] slab_free mm/slub.c:4473 [inline] kfree+0x149/0x360 mm/slub.c:4594 __sk_destruct+0x58/0x5f0 net/core/sock.c:2191 rcu_do_batch kernel/rcu/tree.c:2556 [inline] rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2812 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541 __call_rcu_common kernel/rcu/tree.c:3075 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:3179 pppol2tp_release+0x24b/0x350 net/l2tp/l2tp_ppp.c:457 __sock_release net/socket.c:659 [inline] sock_close+0xbc/0x240 net/socket.c:1421 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802c621800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 184 bytes inside of freed 1024-byte region [ffff88802c621800, ffff88802c621c00) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2c620 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: 0xfdffffff(slab) raw: 00fff00000000040 ffff888015041dc0 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000100010 00000001fdffffff 0000000000000000 head: 00fff00000000040 ffff888015041dc0 dead000000000122 0000000000000000 head: 0000000000000000 0000000000100010 00000001fdffffff 0000000000000000 head: 00fff00000000003 ffffea0000b18801 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 2482, tgid 2482 (kworker/u8:8), ts 115118133561, free_ts 115039940880 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1502 prep_new_page mm/page_alloc.c:1510 [inline] get_page_from_freelist+0x2ccb/0x2d80 mm/page_alloc.c:3489 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4747 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2300 allocate_slab+0x5a/0x2f0 mm/slub.c:2463 new_slab mm/slub.c:2516 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3702 __slab_alloc+0x58/0xa0 mm/slub.c:3792 __slab_alloc_node mm/slub.c:3845 [inline] slab_alloc_node mm/slub.c:4025 [inline] __do_kmalloc_node mm/slub.c:4157 [inline] __kmalloc_noprof+0x257/0x400 mm/slub.c:4171 kmalloc_noprof include/linux/slab.h:664 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] ieee802_11_parse_elems_full+0xdb/0x2880 net/mac80211/parse.c:958 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2361 [inline] ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2368 [inline] ieee80211_inform_bss+0x15f/0x1080 net/mac80211/scan.c:79 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0xe93/0x2030 net/wireless/scan.c:2335 cfg80211_inform_bss_data+0x3dd/0x5a70 net/wireless/scan.c:3159 cfg80211_inform_bss_frame_data+0x3bc/0x720 net/wireless/scan.c:3249 ieee80211_bss_info_update+0x8a7/0xbc0 net/mac80211/scan.c:226 ieee80211_rx_bss_info net/mac80211/ibss.c:1100 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1579 [inline] ieee80211_ibss_rx_queued_mgmt+0x1962/0x2d70 net/mac80211/ibss.c:1606 ieee80211_iface_process_skb net/mac80211/iface.c:1584 [inline] ieee80211_iface_work+0x8a5/0xf20 net/mac80211/iface.c:1638 page last free pid 6488 tgid 6487 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2653 discard_slab mm/slub.c:2562 [inline] __put_partials+0xeb/0x130 mm/slub.c:3030 put_cpu_partial+0x17c/0x250 mm/slub.c:3105 __slab_free+0x2ea/0x3d0 mm/slub.c:4343 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3975 [inline] slab_alloc_node mm/slub.c:4037 [inline] kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4080 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:664 alloc_skb include/linux/skbuff.h:1320 [inline] pfkey_error net/key/af_key.c:316 [inline] pfkey_sendmsg+0xce4/0x1050 net/key/af_key.c:3702 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2680 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88802c621780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802c621800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802c621880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802c621900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802c621980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================