[syzbot] KASAN: slab-out-of-bounds Read in fb_pad_aligned_buffer (3)

Hello,

syzbot found the following issue on:

HEAD commit:    f5bbbfec59b4 Merge tag 'probes-fixes-v7.2-rc7' of git://gi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1687b479580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307
dashboard link: https://syzkaller.appspot.com/bug?extid=bf4020519fbd94b2355d
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12215079580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

==================================================================
BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:646 [inline]
BUG: KASAN: slab-out-of-bounds in fb_pad_aligned_buffer+0x133/0x160 drivers/video/fbdev/core/fbmem.c:96
Read of size 1 at addr ffff8880559fb200 by task syz-executor146/5994

CPU: 0 UID: 0 PID: 5994 Comm: syz-executor146 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __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
 __fb_pad_aligned_buffer include/linux/fb.h:646 [inline]
 fb_pad_aligned_buffer+0x133/0x160 drivers/video/fbdev/core/fbmem.c:96
 cw_putcs_aligned drivers/video/fbdev/core/fbcon_cw.c:105 [inline]
 cw_putcs+0x99c/0xbb0 drivers/video/fbdev/core/fbcon_cw.c:159
 fbcon_putcs+0x3b2/0x480 drivers/video/fbdev/core/fbcon.c:1392
 con_putc+0x144/0x170 drivers/tty/vt/vt.c:330
 hide_softcursor drivers/tty/vt/vt.c:872 [inline]
 hide_cursor+0x1b6/0x230 drivers/tty/vt/vt.c:884
 redraw_screen+0x5d4/0x760 drivers/tty/vt/vt.c:985
 fbcon_do_set_font+0x5b3/0x8c0 drivers/video/fbdev/core/fbcon.c:2441
 fbcon_set_font+0x4be/0x730 drivers/video/fbdev/core/fbcon.c:2518
 con_font_set drivers/tty/vt/vt.c:4992 [inline]
 con_font_op+0x9c0/0x1040 drivers/tty/vt/vt.c:5032
 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
 vt_ioctl+0xe00/0x3150 drivers/tty/vt/vt_ioctl.c:745
 tty_ioctl+0x26a/0x1640 drivers/tty/tty_io.c:2792
 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:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f226c5ec57b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007ffdf3c4c720 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f226c5ec57b
RDX: 00007ffdf3c4c780 RSI: 0000000000004b72 RDI: 0000000000000003
RBP: 000055557cf01770 R08: 00007f226c6747c0 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 000055557cf03780
R13: 00007ffdf3c4c780 R14: 00007f226c66fcc0 R15: 0000000000000002
 </TASK>

Allocated by task 5994:
 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:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5334 [inline]
 __kmalloc_noprof+0x322/0x820 mm/slub.c:5359
 _kmalloc_noprof include/linux/slab.h:992 [inline]
 _kmalloc_array_noprof include/linux/slab.h:1208 [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:2664
 fbcon_set_all_vcs+0x39b/0x470 drivers/video/fbdev/core/fbcon.c:2725
 fbcon_rotate_all drivers/video/fbdev/core/fbcon.c:254 [inline]
 rotate_all_store+0x31e/0x410 drivers/video/fbdev/core/fbcon.c:3218
 dev_attr_store+0x58/0x80 drivers/base/core.c:2505
 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+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880559fa000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 512 bytes to the right of
 allocated 4096-byte region [ffff8880559fa000, ffff8880559fb000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x559f8
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 ffff88801bc43040 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801bc43040 dead000000000100 dead000000000122
head: 0000000000000000 0000000800040004 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 6000, tgid 6000 (dhcpcd-run-hook), ts 75833354126, free_ts 75779299880
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
 alloc_slab_page mm/slub.c:3266 [inline]
 allocate_slab mm/slub.c:3380 [inline]
 new_slab+0xa2/0x640 mm/slub.c:3426
 refill_objects+0xe3/0x410 mm/slub.c:7310
 refill_sheaf mm/slub.c:2804 [inline]
 __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675
 alloc_from_pcs mm/slub.c:4773 [inline]
 slab_alloc_node mm/slub.c:4905 [inline]
 __kmalloc_cache_noprof+0x479/0x6c0 mm/slub.c:5485
 _kmalloc_noprof include/linux/slab.h:988 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 tomoyo_dump_page+0x410/0x540 security/tomoyo/domain.c:916
 tomoyo_scan_bprm security/tomoyo/condition.c:130 [inline]
 tomoyo_condition+0x749/0x3b60 security/tomoyo/condition.c:1120
 tomoyo_check_acl+0x1b7/0x410 security/tomoyo/domain.c:177
 tomoyo_execute_permission+0x176/0x4b0 security/tomoyo/file.c:620
 tomoyo_find_next_domain+0x38d/0x2010 security/tomoyo/domain.c:763
 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:102 [inline]
 tomoyo_bprm_check_security+0x12d/0x1d0 security/tomoyo/tomoyo.c:92
 security_bprm_check+0x87/0x1e0 security/security.c:820
 search_binary_handler fs/exec.c:1684 [inline]
 exec_binprm fs/exec.c:1726 [inline]
 bprm_execve fs/exec.c:1778 [inline]
 bprm_execve+0x84b/0x1730 fs/exec.c:1754
 do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1876
page last free pid 5875 tgid 5875 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 free_pages_prepare+0x586/0xd80 mm/page_alloc.c:1451
 __free_contig_range_common+0x14f/0x250 mm/page_alloc.c:6897
 __free_contig_range mm/page_alloc.c:6942 [inline]
 free_pages_bulk+0x12a/0x200 mm/page_alloc.c:5257
 vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3461
 vfree mm/vmalloc.c:3510 [inline]
 vfree+0x107/0x750 mm/vmalloc.c:3484
 delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3414
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff8880559fb100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880559fb180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880559fb200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff8880559fb280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880559fb300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email protected].

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup