================================================================== BUG: KASAN: slab-out-of-bounds in soft_cursor+0x458/0xa10 drivers/video/fbdev/core/softcursor.c:70 Read of size 42 at addr ffff8880574f774c by task syz.6.2360/12688 CPU: 2 UID: 0 PID: 12688 Comm: syz.6.2360 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:186 [inline] kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200 __asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105 soft_cursor+0x458/0xa10 drivers/video/fbdev/core/softcursor.c:70 ccw_cursor+0xd7f/0x15b0 drivers/video/fbdev/core/fbcon_ccw.c:341 fbcon_cursor+0x43c/0x5e0 drivers/video/fbdev/core/fbcon.c:1434 hide_cursor+0x87/0x230 drivers/tty/vt/vt.c:883 con_font_set drivers/tty/vt/vt.c:4993 [inline] con_font_op+0x905/0x1020 drivers/tty/vt/vt.c:5036 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline] vt_ioctl+0xe00/0x3170 drivers/tty/vt/vt_ioctl.c:747 tty_ioctl+0x26a/0x1870 drivers/tty/tty_io.c:2782 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2adb39f559 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:00007f2adc325028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f2adb625fa0 RCX: 00007f2adb39f559 RDX: 00002000000003c0 RSI: 0000000000004b72 RDI: 0000000000000003 RBP: 00007f2adb436b20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2adb626038 R14: 00007f2adb625fa0 R15: 00007ffdcc057428 Allocated by task 6421: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:409 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5414 [inline] __kmalloc_noprof+0x32f/0x840 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] _kmalloc_array_noprof include/linux/slab.h:1211 [inline] font_data_rotate+0x353/0x3b0 lib/fonts/font_rotate.c:231 fbcon_rotate_font+0x2bf/0x510 drivers/video/fbdev/core/fbcon_rotate.c:33 fbcon_modechanged+0x218/0x7f0 drivers/video/fbdev/core/fbcon.c:2671 fbcon_rotate drivers/video/fbdev/core/fbcon.c:230 [inline] rotate_store+0x261/0x300 drivers/video/fbdev/core/fbcon.c:3203 dev_attr_store+0x58/0x80 drivers/base/core.c:2509 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6af/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880574f6000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1868 bytes to the right of allocated 4096-byte region [ffff8880574f6000, ffff8880574f7000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x574f0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801d043040 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801d043040 dead000000000100 dead000000000122 head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6270, tgid 6270 (dhcpcd-run-hook), ts 68575005862 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab mm/slub.c:3462 [inline] new_slab+0xa9/0x6e0 mm/slub.c:3513 refill_objects+0xe3/0x410 mm/slub.c:7418 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __do_kmalloc_node mm/slub.c:5413 [inline] __kmalloc_noprof+0x67c/0x840 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] tomoyo_realpath_from_path+0xb6/0x690 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x2af/0x3c0 security/tomoyo/file.c:776 tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334 security_file_open+0xb5/0x1e0 security/security.c:2739 do_dentry_open+0x552/0x1470 fs/open.c:977 vfs_open_consume+0xcc/0x460 fs/open.c:1131 do_open fs/namei.c:4845 [inline] path_openat+0x1551/0x2430 fs/namei.c:5010 do_file_open+0x20e/0x430 fs/namei.c:5039 do_sys_openat2+0x163/0x1d0 fs/open.c:1442 page last free pid 6267 tgid 6267 ts 68539131595 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:361 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] slab_alloc_node mm/slub.c:4996 [inline] kmem_cache_alloc_noprof+0x269/0x6a0 mm/slub.c:5010 lsm_file_alloc security/security.c:171 [inline] security_file_alloc+0x34/0x2c0 security/security.c:2406 init_file+0x95/0x480 fs/file_table.c:184 alloc_empty_file+0x79/0x1c0 fs/file_table.c:266 path_openat+0xdb/0x2430 fs/namei.c:4996 do_file_open+0x20e/0x430 fs/namei.c:5039 do_sys_openat2+0x163/0x1d0 fs/open.c:1442 do_sys_open fs/open.c:1448 [inline] __do_sys_openat fs/open.c:1464 [inline] __se_sys_openat fs/open.c:1459 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1459 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880574f7600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880574f7680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880574f7700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880574f7780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880574f7800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================