================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:674 [inline] BUG: KASAN: slab-out-of-bounds in fb_pad_aligned_buffer+0x137/0x150 drivers/video/fbdev/core/fbmem.c:122 Read of size 1 at addr ffff8880a4ea79d0 by task syz-executor.5/17164 CPU: 0 PID: 17164 Comm: syz-executor.5 Not tainted 4.19.107-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_address_description.cold+0x7c/0x212 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396 __fb_pad_aligned_buffer include/linux/fb.h:674 [inline] fb_pad_aligned_buffer+0x137/0x150 drivers/video/fbdev/core/fbmem.c:122 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:99 [inline] bit_putcs+0xc21/0xe10 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x434/0x4f0 drivers/video/fbdev/core/fbcon.c:1320 con_flush drivers/tty/vt/vt.c:2533 [inline] do_con_write.part.0+0xf37/0x1db0 drivers/tty/vt/vt.c:2783 do_con_write drivers/tty/vt/vt.c:2552 [inline] con_write+0x41/0xe0 drivers/tty/vt/vt.c:3121 process_output_block drivers/tty/n_tty.c:593 [inline] n_tty_write+0x3ee/0x1080 drivers/tty/n_tty.c:2331 do_tty_write drivers/tty/tty_io.c:960 [inline] tty_write+0x452/0x790 drivers/tty/tty_io.c:1044 __vfs_write+0xf7/0x760 fs/read_write.c:485 vfs_write+0x206/0x550 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c479 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fb47b41bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fb47b41c6d4 RCX: 000000000045c479 RDX: 0000000000000089 RSI: 0000000020000000 RDI: 0000000000000007 RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000cda R14: 00000000004cebe8 R15: 000000000076bfcc Allocated by task 1784: set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531 __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15b/0x770 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] fbcon_set_font+0x331/0x870 drivers/video/fbdev/core/fbcon.c:2641 con_font_set drivers/tty/vt/vt.c:4503 [inline] con_font_op+0xd3e/0x1130 drivers/tty/vt/vt.c:4568 vt_ioctl+0x1615/0x2310 drivers/tty/vt/vt_ioctl.c:970 tty_ioctl+0x7a1/0x1420 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 24752: set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521 __cache_free mm/slab.c:3503 [inline] kfree+0xce/0x220 mm/slab.c:3822 snd_seq_oss_readq_delete+0x33/0x50 sound/core/seq/oss/seq_oss_readq.c:78 free_devinfo+0x87/0xb0 sound/core/seq/oss/seq_oss_init.c:408 port_delete+0xd7/0x1a0 sound/core/seq/seq_ports.c:273 snd_seq_delete_port+0x25b/0x320 sound/core/seq/seq_ports.c:303 snd_seq_ioctl_delete_port+0xb3/0x180 sound/core/seq/seq_clientmgr.c:1333 snd_seq_kernel_client_ctl+0xeb/0x130 sound/core/seq/seq_clientmgr.c:2355 snd_seq_event_port_detach+0xa4/0xe0 sound/core/seq/seq_ports.c:708 delete_port+0x79/0xc0 sound/core/seq/oss/seq_oss_init.c:354 snd_seq_oss_release+0xeb/0x140 sound/core/seq/oss/seq_oss_init.c:433 odev_release+0x4f/0x70 sound/core/seq/oss/seq_oss.c:153 __fput+0x2cd/0x890 fs/file_table.c:278 task_work_run+0x13f/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x25a/0x2b0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a4ea5a00 which belongs to the cache kmalloc-8192 of size 8192 The buggy address is located 8144 bytes inside of 8192-byte region [ffff8880a4ea5a00, ffff8880a4ea7a00) The buggy address belongs to the page: page:ffffea000293a900 count:1 mapcount:0 mapping:ffff88812c3d5080 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea0000ec1408 ffffea0002a21208 ffff88812c3d5080 raw: 0000000000000000 ffff8880a4ea5a00 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a4ea7880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a4ea7900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a4ea7980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a4ea7a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a4ea7a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================