================================================================== BUG: KASAN: slab-use-after-free in scr_memcpyw include/linux/vt_buffer.h:38 [inline] BUG: KASAN: slab-use-after-free in fbcon_prepare_logo+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:613 Read of size 14 at addr ffff88803129b43e by task syz.0.744/9211 CPU: 0 UID: 0 PID: 9211 Comm: syz.0.744 Not tainted 6.15.0-rc7-syzkaller-00142-g4856ebd99715 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 __asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105 scr_memcpyw include/linux/vt_buffer.h:38 [inline] fbcon_prepare_logo+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:613 fbcon_init+0xd77/0x1900 drivers/video/fbdev/core/fbcon.c:1145 visual_init+0x31d/0x620 drivers/tty/vt/vt.c:1011 do_bind_con_driver.isra.0+0x57a/0xbf0 drivers/tty/vt/vt.c:3831 vt_bind drivers/tty/vt/vt.c:3987 [inline] store_bind+0x61d/0x760 drivers/tty/vt/vt.c:4059 dev_attr_store+0x55/0x80 drivers/base/core.c:2440 sysfs_kf_write+0xef/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x351/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x5bd/0x1180 fs/read_write.c:684 ksys_write+0x12a/0x240 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5ad198e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5ad27fa038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f5ad1bb6160 RCX: 00007f5ad198e969 RDX: 00000000fffffdef RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f5ad1a10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5ad1bb6160 R15: 00007ffddbc19488 Allocated by task 3522: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4339 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] cfg80211_inform_single_bss_data+0x53e/0x1df0 net/wireless/scan.c:2339 cfg80211_inform_bss_data+0x224/0x3bc0 net/wireless/scan.c:3222 cfg80211_inform_bss_frame_data+0x26e/0x7a0 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x310/0xab0 net/mac80211/scan.c:226 ieee80211_rx_bss_info net/mac80211/ibss.c:1102 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1581 [inline] ieee80211_ibss_rx_queued_mgmt+0x1905/0x2fd0 net/mac80211/ibss.c:1608 ieee80211_iface_process_skb net/mac80211/iface.c:1625 [inline] ieee80211_iface_work+0xbf4/0x1020 net/mac80211/iface.c:1679 cfg80211_wiphy_work+0x3df/0x550 net/wireless/core.c:435 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 7208: 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:2380 [inline] slab_free_freelist_hook mm/slub.c:2409 [inline] slab_free_bulk mm/slub.c:4666 [inline] kmem_cache_free_bulk.part.0+0x38d/0x7f0 mm/slub.c:5243 kfree_bulk include/linux/slab.h:794 [inline] kvfree_rcu_bulk+0x1bb/0x1f0 mm/slab_common.c:1516 kvfree_rcu_drain_ready mm/slab_common.c:1699 [inline] kfree_rcu_monitor+0x1d0/0x2f0 mm/slab_common.c:1772 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xb8/0xd0 mm/kasan/generic.c:548 kvfree_call_rcu+0x76/0x470 mm/slab_common.c:1962 cfg80211_update_known_bss+0x39f/0x11a0 net/wireless/scan.c:1925 __cfg80211_bss_update+0x1b7/0x23c0 net/wireless/scan.c:1972 cfg80211_inform_single_bss_data+0x7ba/0x1df0 net/wireless/scan.c:2363 cfg80211_inform_bss_data+0x224/0x3bc0 net/wireless/scan.c:3222 cfg80211_inform_bss_frame_data+0x26e/0x7a0 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x310/0xab0 net/mac80211/scan.c:226 ieee80211_scan_rx+0x475/0xae0 net/mac80211/scan.c:340 __ieee80211_rx_handle_packet net/mac80211/rx.c:5179 [inline] ieee80211_rx_list+0x1bdb/0x2980 net/mac80211/rx.c:5416 ieee80211_rx_napi+0xdc/0x410 net/mac80211/rx.c:5439 ieee80211_rx include/net/mac80211.h:5179 [inline] ieee80211_handle_queued_frames+0xd5/0x130 net/mac80211/main.c:441 tasklet_action_common+0x284/0x400 kernel/softirq.c:829 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 run_ksoftirqd kernel/softirq.c:968 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:960 smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:164 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88803129b400 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 62 bytes inside of freed 96-byte region [ffff88803129b400, ffff88803129b460) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3129b anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b441280 ffffea0000b6a600 dead000000000005 raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 36, tgid 36 (kworker/u8:2), ts 114368143055, free_ts 114157467669 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1714 prep_new_page mm/page_alloc.c:1722 [inline] get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3684 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4966 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab mm/slub.c:2618 [inline] new_slab+0x244/0x340 mm/slub.c:2672 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3858 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948 __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] __do_kmalloc_node mm/slub.c:4326 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4339 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] cfg80211_inform_single_bss_data+0x53e/0x1df0 net/wireless/scan.c:2339 cfg80211_inform_bss_data+0x224/0x3bc0 net/wireless/scan.c:3222 cfg80211_inform_bss_frame_data+0x26e/0x7a0 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x310/0xab0 net/mac80211/scan.c:226 ieee80211_rx_bss_info net/mac80211/ibss.c:1102 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1581 [inline] ieee80211_ibss_rx_queued_mgmt+0x1905/0x2fd0 net/mac80211/ibss.c:1608 ieee80211_iface_process_skb net/mac80211/iface.c:1625 [inline] ieee80211_iface_work+0xbf4/0x1020 net/mac80211/iface.c:1679 cfg80211_wiphy_work+0x3df/0x550 net/wireless/core.c:435 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 page last free pid 5819 tgid 5819 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1258 [inline] __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2721 __folio_put+0x329/0x450 mm/swap.c:112 folio_put include/linux/mm.h:1580 [inline] put_page include/linux/mm.h:1649 [inline] anon_pipe_put_page fs/pipe.c:140 [inline] anon_pipe_buf_release+0x3ed/0x500 fs/pipe.c:148 pipe_buf_release include/linux/pipe_fs_i.h:282 [inline] pipe_update_tail fs/pipe.c:243 [inline] anon_pipe_read+0x5cd/0x1210 fs/pipe.c:362 new_sync_read fs/read_write.c:489 [inline] vfs_read+0xaa6/0xc70 fs/read_write.c:570 ksys_read+0x205/0x240 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88803129b300: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88803129b380: 00 00 00 00 00 00 00 00 06 fc fc fc fc fc fc fc >ffff88803129b400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88803129b480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88803129b500: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================