================================================================== 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:618 Read of size 14 at addr ffff88807a07f550 by task syz.1.3495/23500 CPU: 1 UID: 0 PID: 23500 Comm: syz.1.3495 Not tainted 6.16.0-rc1-syzkaller-00239-g08215f5486ec #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+0xcd/0x680 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+0x100/0x1b0 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:618 fbcon_init+0xd77/0x1900 drivers/video/fbdev/core/fbcon.c:1150 visual_init+0x320/0x620 drivers/tty/vt/vt.c:1019 do_bind_con_driver.isra.0+0x57a/0xbf0 drivers/tty/vt/vt.c:3915 vt_bind drivers/tty/vt/vt.c:4071 [inline] store_bind+0x61d/0x760 drivers/tty/vt/vt.c:4143 dev_attr_store+0x55/0x80 drivers/base/core.c:2440 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x354/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c4/0x1150 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f09dff8e929 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:00007f09e0d96038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f09e01b6080 RCX: 00007f09dff8e929 RDX: 00000000fffffdef RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f09e0010b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f09e01b6080 R15: 00007ffe45ec8fc8 Allocated by task 23500: 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:4328 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] vc_do_resize+0x1de/0x10e0 drivers/tty/vt/vt.c:1182 vc_resize include/linux/vt_kern.h:49 [inline] fbcon_startup+0x427/0xba0 drivers/video/fbdev/core/fbcon.c:1001 do_bind_con_driver.isra.0+0x207/0xbf0 drivers/tty/vt/vt.c:3878 vt_bind drivers/tty/vt/vt.c:4071 [inline] store_bind+0x61d/0x760 drivers/tty/vt/vt.c:4143 dev_attr_store+0x55/0x80 drivers/base/core.c:2440 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x354/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c4/0x1150 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 23500: 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] kfree+0x2b4/0x4d0 mm/slub.c:4842 vc_do_resize+0xe29/0x10e0 drivers/tty/vt/vt.c:1202 vc_resize include/linux/vt_kern.h:49 [inline] fbcon_startup+0x427/0xba0 drivers/video/fbdev/core/fbcon.c:1001 do_bind_con_driver.isra.0+0x207/0xbf0 drivers/tty/vt/vt.c:3878 vt_bind drivers/tty/vt/vt.c:4071 [inline] store_bind+0x61d/0x760 drivers/tty/vt/vt.c:4143 dev_attr_store+0x55/0x80 drivers/base/core.c:2440 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x354/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c4/0x1150 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807a07f500 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 80 bytes inside of freed 96-byte region [ffff88807a07f500, ffff88807a07f560) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7a07f ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b841280 ffffea0000abdf00 dead000000000003 raw: 0000000000000000 0000000080200020 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 11296, tgid 11296 (kworker/u8:12), ts 969135786628, free_ts 968707289801 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] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4340 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+0x26f/0x750 net/wireless/scan.c:3313 ieee80211_bss_info_update+0x310/0xab0 net/mac80211/scan.c:226 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1573 [inline] ieee80211_ibss_rx_queued_mgmt+0x1905/0x2fd0 net/mac80211/ibss.c:1600 ieee80211_iface_process_skb net/mac80211/iface.c:1668 [inline] ieee80211_iface_work+0xbf4/0x1020 net/mac80211/iface.c:1722 cfg80211_wiphy_work+0x3df/0x550 net/wireless/core.c:435 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 page last free pid 23 tgid 23 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 pagetable_free include/linux/mm.h:2879 [inline] pagetable_dtor_free include/linux/mm.h:2977 [inline] __tlb_remove_table include/asm-generic/tlb.h:220 [inline] __tlb_remove_table_free mm/mmu_gather.c:227 [inline] tlb_remove_table_rcu+0x116/0x1a0 mm/mmu_gather.c:290 rcu_do_batch kernel/rcu/tree.c:2576 [inline] rcu_core+0x79c/0x14e0 kernel/rcu/tree.c:2832 handle_softirqs+0x219/0x8e0 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+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88807a07f400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88807a07f480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff88807a07f500: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88807a07f580: 00 00 00 00 00 00 00 00 00 00 04 fc fc fc fc fc ffff88807a07f600: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc ==================================================================