Console: switching to colour VGA+ 80x25 ================================================================== BUG: KASAN: slab-out-of-bounds in scr_memcpyw include/linux/vt_buffer.h:38 [inline] BUG: KASAN: slab-out-of-bounds in fbcon_prepare_logo+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:618 Read of size 256 at addr ffff888025aa5860 by task syz.1.2534/12336 CPU: 1 UID: 0 PID: 12336 Comm: syz.1.2534 Not tainted 6.16.0-rc4-syzkaller-00108-g17bbde2e1716 #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+0x58/0x80 drivers/base/core.c:2440 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x351/0x510 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: 0033:0x7f78f018e929 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:00007f78f0f3c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f78f03b5fa0 RCX: 00007f78f018e929 RDX: 00000000fffffdef RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f78f0210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f78f03b5fa0 R15: 00007ffd73e936c8 Allocated by task 12098: 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] __vb2_queue_alloc+0x23e/0x1280 drivers/media/common/videobuf2/videobuf2-core.c:502 vb2_core_reqbufs+0xa90/0xfe0 drivers/media/common/videobuf2/videobuf2-core.c:964 __vb2_init_fileio+0x3f1/0x1100 drivers/media/common/videobuf2/videobuf2-core.c:2895 __vb2_perform_fileio+0x9c2/0x1660 drivers/media/common/videobuf2/videobuf2-core.c:3041 vb2_fop_read+0x215/0x3e0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1214 v4l2_read+0x229/0x360 drivers/media/v4l2-core/v4l2-dev.c:316 vfs_read+0x1e4/0xc60 fs/read_write.c:570 ksys_read+0x12a/0x250 fs/read_write.c:715 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 12098: 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 __vb2_queue_free+0x6f4/0xa30 drivers/media/common/videobuf2/videobuf2-core.c:691 vb2_core_reqbufs+0x276/0xfe0 drivers/media/common/videobuf2/videobuf2-core.c:911 __vb2_cleanup_fileio+0xed/0x190 drivers/media/common/videobuf2/videobuf2-core.c:2993 vb2_core_queue_release+0x1f/0x190 drivers/media/common/videobuf2/videobuf2-core.c:2692 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:956 [inline] _vb2_fop_release+0xe8/0x280 drivers/media/common/videobuf2/videobuf2-v4l2.c:1158 vivid_fop_release+0x155/0xc40 drivers/media/test-drivers/vivid/vivid-core.c:667 v4l2_release+0x232/0x460 drivers/media/v4l2-core/v4l2-dev.c:458 __fput+0x402/0xb70 fs/file_table.c:465 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x490 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888025aa5000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 96 bytes to the right of allocated 2048-byte region [ffff888025aa5000, ffff888025aa5800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25aa0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b842000 0000000000000000 dead000000000001 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842000 0000000000000000 dead000000000001 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea000096a801 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 1, tgid 1 (swapper/0), ts 14613808361, free_ts 0 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] __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] serial_base_ctrl_add+0x4c/0x3b0 drivers/tty/serial/serial_base_bus.c:114 serial_core_ctrl_device_add drivers/tty/serial/serial_core.c:3333 [inline] serial_core_register_port+0x3a1/0x2570 drivers/tty/serial/serial_core.c:3369 serial8250_register_8250_port+0x159b/0x23c0 drivers/tty/serial/8250/8250_core.c:822 serial_pnp_probe+0x431/0x910 drivers/tty/serial/8250/8250_pnp.c:480 pnp_device_probe+0x2a5/0x4d0 drivers/pnp/driver.c:111 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x241/0xa90 drivers/base/dd.c:657 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829 page_owner free stack trace missing Memory state around the buggy address: ffff888025aa5700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888025aa5780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888025aa5800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888025aa5880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888025aa5900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================