================================================================== BUG: KASAN: slab-use-after-free in z_erofs_decompress_kickoff+0x371/0x3d0 fs/erofs/zdata.c:1475 Read of size 4 at addr ffff888065039968 by task kworker/u8:13/5808 CPU: 1 UID: 0 PID: 5808 Comm: kworker/u8:13 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 z_erofs_decompress_kickoff+0x371/0x3d0 fs/erofs/zdata.c:1475 z_erofs_endio+0xb28/0xd40 fs/erofs/zdata.c:1655 blk_update_request+0x57e/0xe60 block/blk-mq.c:1016 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1178 blk_complete_reqs block/blk-mq.c:1253 [inline] blk_done_softirq+0x10a/0x160 block/blk-mq.c:1258 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302 local_bh_enable include/linux/bottom_half.h:33 [inline] spin_unlock_bh include/linux/spinlock_rt.h:116 [inline] wg_index_hashtable_insert+0x12e/0x8c0 drivers/net/wireguard/peerlookup.c:126 wg_noise_handshake_create_initiation+0x64e/0x830 drivers/net/wireguard/noise.c:569 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0x18d/0x350 drivers/net/wireguard/send.c:51 process_one_work+0x9a3/0x1710 kernel/workqueue.c:3312 process_scheduled_works kernel/workqueue.c:3403 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3489 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 10011: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5427 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] erofs_init_fs_context+0x54/0x290 fs/erofs/super.c:897 alloc_fs_context+0x9d5/0xd50 fs/fs_context.c:295 do_new_mount+0x187/0xd30 fs/namespace.c:3814 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5611: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2700 [inline] slab_free mm/slub.c:6258 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6573 erofs_sb_free fs/erofs/super.c:875 [inline] erofs_kill_sb+0x26a/0x2a0 fs/erofs/super.c:939 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888065039800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 360 bytes inside of freed 1024-byte region [ffff888065039800, ffff888065039c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6503[ 694.792263][ C1] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x65038 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe15dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe15dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000002be4 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 30, tgid 30 (ktimers/1), ts 174831828958, free_ts 174792463503 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1853 prep_new_page mm/page_alloc.c:1861 [inline] get_page_from_freelist+0x27d6/0x2850 mm/page_alloc.c:3941 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5249 alloc_slab_page mm/slub.c:3289 [inline] allocate_slab+0x74/0x5e0 mm/slub.c:3404 new_slab mm/slub.c:3447 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7263 refill_sheaf mm/slub.c:2827 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4659 alloc_from_pcs mm/slub.c:4757 [inline] slab_alloc_node mm/slub.c:4891 [inline] __do_kmalloc_node mm/slub.c:5302 [inline] __kmalloc_noprof+0x530/0x7b0 mm/slub.c:5315 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] ieee802_11_parse_elems_full+0x159/0x2ab0 net/mac80211/parse.c:1051 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2501 [inline] ieee80211_inform_bss+0x161/0x1160 net/mac80211/scan.c:79 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0xd2f/0x1b80 net/wireless/scan.c:2372 cfg80211_inform_bss_data+0x266/0x3c40 net/wireless/scan.c:3226 cfg80211_inform_bss_frame_data+0x3c7/0x730 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230 ieee80211_scan_rx+0x552/0xa40 net/mac80211/scan.c:364 __ieee80211_rx_handle_packet net/mac80211/rx.c:5353 [inline] ieee80211_rx_list+0x2a2f/0x37a0 net/mac80211/rx.c:5638 ieee80211_rx_napi+0x1b1/0x3e0 net/mac80211/rx.c:5661 page last free pid 43 tgid 43 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] __free_frozen_pages+0x1075/0x11b0 mm/page_alloc.c:2938 skb_free_frag include/linux/skbuff.h:3534 [inline] skb_free_head net/core/skbuff.c:1085 [inline] skb_release_data+0x8a5/0xa60 net/core/skbuff.c:1114 skb_release_all net/core/skbuff.c:1189 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1203 batadv_forw_packet_free+0x65/0x1f0 net/batman-adv/send.c:458 process_one_work+0x9a3/0x1710 kernel/workqueue.c:3312 process_scheduled_works kernel/workqueue.c:3403 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3489 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888065039800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888065039880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888065039900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888065039980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888065039a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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