================================================================== BUG: KASAN: slab-out-of-bounds in soft_cursor+0x38e/0xc40 drivers/video/fbdev/core/softcursor.c:70 Read of size 150 at addr ffff88804247d2c0 by task syz.0.388/7573 CPU: 1 UID: 0 PID: 7573 Comm: syz.0.388 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 soft_cursor+0x38e/0xc40 drivers/video/fbdev/core/softcursor.c:70 cw_cursor+0x16e0/0x1ff0 drivers/video/fbdev/core/fbcon_cw.c:324 hide_cursor+0xd3/0x490 drivers/tty/vt/vt.c:883 redraw_screen+0x1f2/0x1020 drivers/tty/vt/vt.c:985 vc_do_resize+0xffc/0x1550 drivers/tty/vt/vt.c:1309 vc_resize include/linux/vt_kern.h:49 [inline] fbcon_do_set_font+0x93f/0x1d00 drivers/video/fbdev/core/fbcon.c:2435 fbcon_set_font+0x6f5/0x970 drivers/video/fbdev/core/fbcon.c:2518 con_font_set drivers/tty/vt/vt.c:4992 [inline] con_font_op+0xc37/0xfe0 drivers/tty/vt/vt.c:5032 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:472 [inline] vt_ioctl+0x1b93/0x20d0 drivers/tty/vt/vt_ioctl.c:743 tty_ioctl+0x926/0xde0 drivers/tty/tty_io.c:2792 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1b506ee0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1b4e4e1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1b50976270 RCX: 00007f1b506ee0d9 RDX: 0000200000000240 RSI: 0000000000004b72 RDI: 0000000000000003 RBP: 00007f1b50785024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1b50976308 R14: 00007f1b50976270 R15: 00007ffdbd30fac8 Allocated by task 7560: 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] __do_kmalloc_node mm/slub.c:5339 [inline] __kmalloc_noprof+0x415/0x790 mm/slub.c:5364 _kmalloc_noprof include/linux/slab.h:973 [inline] _kmalloc_array_noprof include/linux/slab.h:1189 [inline] font_data_rotate+0x10b/0x840 lib/fonts/font_rotate.c:231 fbcon_rotate_font+0x2c3/0x490 drivers/video/fbdev/core/fbcon_rotate.c:33 fbcon_switch+0xd5e/0x20b0 drivers/video/fbdev/core/fbcon.c:2217 redraw_screen+0x57b/0x1020 drivers/tty/vt/vt.c:994 vc_do_resize+0xffc/0x1550 drivers/tty/vt/vt.c:1309 vc_resize include/linux/vt_kern.h:49 [inline] fbcon_modechanged+0x6ed/0x1140 drivers/video/fbdev/core/fbcon.c:2653 fbcon_rotate_all drivers/video/fbdev/core/fbcon.c:254 [inline] rotate_all_store+0x539/0x630 drivers/video/fbdev/core/fbcon.c:3193 kernfs_fop_write_iter+0x3a5/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61e/0xbb0 fs/read_write.c:687 ksys_write+0x156/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88804247c000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 704 bytes to the right of allocated 4096-byte region [ffff88804247c000, ffff88804247d000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x42478 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 ffff88813fe3c140 dead000000000122 0000000000000000 raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe3c140 dead000000000122 0000000000000000 head: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7560, tgid 7558 (syz.5.385), ts 251047313030 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x264c/0x26c0 mm/page_alloc.c:3955 __alloc_frozen_pages_noprof+0x222/0x5b0 mm/page_alloc.c:5394 alloc_slab_page mm/slub.c:3295 [inline] allocate_slab+0x7c/0x5e0 mm/slub.c:3410 new_slab mm/slub.c:3456 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7321 refill_sheaf mm/slub.c:2833 [inline] __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4699 alloc_from_pcs mm/slub.c:4775 [inline] slab_alloc_node mm/slub.c:4909 [inline] __do_kmalloc_node mm/slub.c:5338 [inline] __kmalloc_noprof+0x543/0x790 mm/slub.c:5364 _kmalloc_noprof include/linux/slab.h:973 [inline] tomoyo_realpath_from_path+0xef/0x640 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x229/0x470 security/tomoyo/file.c:776 security_file_open+0x9c/0x200 security/security.c:2739 do_dentry_open+0x4be/0x1420 fs/open.c:924 vfs_open+0x3b/0x350 fs/open.c:1052 do_open fs/namei.c:4694 [inline] path_openat+0x2e64/0x3850 fs/namei.c:4857 do_file_open+0x23e/0x4a0 fs/namei.c:4886 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 page last free pid 4959 tgid 4959 ts 250540112589 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0x1185/0x1270 mm/page_alloc.c:2962 __slab_free+0x252/0x2a0 mm/slub.c:5738 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4608 [inline] slab_alloc_node mm/slub.c:4921 [inline] kmem_cache_alloc_noprof+0x358/0x680 mm/slub.c:4935 alloc_filename fs/namei.c:147 [inline] do_getname+0x2e/0x250 fs/namei.c:187 class_filename_flags_constructor include/linux/fs.h:2564 [inline] do_readlinkat+0xc8/0x510 fs/stat.c:569 __do_sys_readlink fs/stat.c:605 [inline] __se_sys_readlink fs/stat.c:602 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:602 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88804247d180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88804247d200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88804247d280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88804247d300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88804247d380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================