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:613 Read of size 14 at addr ffff888025f724fe by task syz.5.2340/17402 CPU: 1 UID: 0 PID: 17402 Comm: syz.5.2340 Tainted: G U 6.15.0-rc7-syzkaller-00007-g4a95bc121ccd #0 PREEMPT(full) Tainted: [U]=USER 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+0x58/0x80 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: 0033:0x7fc89f38e969 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:00007fc89d1f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc89f5b5fa0 RCX: 00007fc89f38e969 RDX: 00000000fffffdef RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fc89f410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc89f5b5fa0 R15: 00007fff52d24e58 Allocated by task 17402: 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_node_track_caller_noprof+0x221/0x510 mm/slub.c:4346 __do_krealloc mm/slub.c:4904 [inline] krealloc_noprof+0x1fb/0x380 mm/slub.c:4957 krealloc_array_noprof include/linux/slab.h:979 [inline] drm_atomic_get_connector_state+0x231/0x740 drivers/gpu/drm/drm_atomic.c:1084 drm_atomic_add_affected_connectors+0x2e0/0x3f0 drivers/gpu/drm/drm_atomic.c:1324 update_output_state drivers/gpu/drm/drm_atomic.c:1591 [inline] __drm_atomic_helper_set_config+0x5ef/0xea0 drivers/gpu/drm/drm_atomic.c:1711 drm_client_modeset_commit_atomic+0x53d/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1060 drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1182 pan_display_atomic drivers/gpu/drm/drm_fb_helper.c:1387 [inline] drm_fb_helper_pan_display+0x32d/0xa40 drivers/gpu/drm/drm_fb_helper.c:1447 fb_pan_display+0x47c/0x7d0 drivers/video/fbdev/core/fbmem.c:191 bit_update_start+0x49/0x1f0 drivers/video/fbdev/core/bitblit.c:380 fbcon_switch+0xbf8/0x14c0 drivers/video/fbdev/core/fbcon.c:2187 redraw_screen+0x2c1/0x760 drivers/tty/vt/vt.c:957 vc_do_resize+0xed0/0x10e0 drivers/tty/vt/vt.c:1272 vc_resize include/linux/vt_kern.h:49 [inline] fbcon_init+0xd53/0x1900 drivers/video/fbdev/core/fbcon.c:1142 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+0x58/0x80 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 Freed by task 17402: 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 mm/slub.c:4642 [inline] kfree+0x2b6/0x4d0 mm/slub.c:4841 drm_atomic_state_default_release drivers/gpu/drm/drm_atomic.c:107 [inline] __drm_atomic_state_free+0x1b7/0x2b0 drivers/gpu/drm/drm_atomic.c:317 kref_put include/linux/kref.h:65 [inline] drm_atomic_state_put include/drm/drm_atomic.h:588 [inline] drm_client_modeset_commit_atomic+0x6b2/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1085 drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1182 pan_display_atomic drivers/gpu/drm/drm_fb_helper.c:1387 [inline] drm_fb_helper_pan_display+0x32d/0xa40 drivers/gpu/drm/drm_fb_helper.c:1447 fb_pan_display+0x47c/0x7d0 drivers/video/fbdev/core/fbmem.c:191 bit_update_start+0x49/0x1f0 drivers/video/fbdev/core/bitblit.c:380 fbcon_switch+0xbf8/0x14c0 drivers/video/fbdev/core/fbcon.c:2187 redraw_screen+0x2c1/0x760 drivers/tty/vt/vt.c:957 vc_do_resize+0xed0/0x10e0 drivers/tty/vt/vt.c:1272 vc_resize include/linux/vt_kern.h:49 [inline] fbcon_init+0xd53/0x1900 drivers/video/fbdev/core/fbcon.c:1142 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+0x58/0x80 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 The buggy address belongs to the object at ffff888025f72480 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 30 bytes to the right of allocated 96-byte region [ffff888025f72480, ffff888025f724e0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25f72 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b441280 dead000000000100 dead000000000122 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 1, tgid 1 (swapper/0), ts 15118637479, free_ts 0 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_slab_page mm/slub.c:2452 [inline] allocate_slab mm/slub.c:2618 [inline] new_slab+0x94/0x340 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] __kmalloc_cache_node_noprof+0x100/0x420 mm/slub.c:4366 kmalloc_node_noprof include/linux/slab.h:928 [inline] alloc_node_nr_active kernel/workqueue.c:4872 [inline] __alloc_workqueue+0x506/0x1810 kernel/workqueue.c:5726 alloc_workqueue+0xd2/0x200 kernel/workqueue.c:5786 nbd_dev_add+0x526/0xbb0 drivers/block/nbd.c:1940 nbd_init+0x181/0x320 drivers/block/nbd.c:2670 do_one_initcall+0x120/0x6e0 init/main.c:1257 do_initcall_level init/main.c:1319 [inline] do_initcalls init/main.c:1335 [inline] do_basic_setup init/main.c:1354 [inline] kernel_init_freeable+0x5c2/0x900 init/main.c:1567 kernel_init+0x1c/0x2b0 init/main.c:1457 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page_owner free stack trace missing Memory state around the buggy address: ffff888025f72380: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff888025f72400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888025f72480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888025f72500: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc ffff888025f72580: 00 00 00 00 00 00 00 00 00 00 04 fc fc fc fc fc ==================================================================