================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:654 [inline] BUG: KASAN: slab-out-of-bounds in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] BUG: KASAN: slab-out-of-bounds in bit_putcs+0x132a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff888052db1f50 by task syz-executor.2/5435 CPU: 1 PID: 5435 Comm: syz-executor.2 Not tainted 5.9.0-rc8-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+0x1d6/0x29e lib/dump_stack.c:118 print_address_description+0x66/0x620 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0 mm/kasan/report.c:530 __fb_pad_aligned_buffer include/linux/fb.h:654 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0x132a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x790/0xaf0 drivers/video/fbdev/core/fbcon.c:1308 do_update_region+0x462/0x620 drivers/tty/vt/vt.c:675 update_region+0x1c7/0x8d0 drivers/tty/vt/vt.c:693 vcs_write+0x9db/0xc70 drivers/tty/vt/vc_screen.c:623 vfs_write+0x2d3/0xd10 fs/read_write.c:584 ksys_write+0x11b/0x220 fs/read_write.c:639 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45de59 Code: 0d b4 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ff6df8cdc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000003a100 RCX: 000000000045de59 RDX: 00000000000000a0 RSI: 00000000200001c0 RDI: 0000000000000003 RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffe6483df1f R14: 00007ff6df8ce9c0 R15: 000000000118bf2c Allocated by task 10548: kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461 __do_kmalloc mm/slab.c:3659 [inline] __kmalloc+0x205/0x300 mm/slab.c:3668 kmalloc include/linux/slab.h:559 [inline] fbcon_set_font+0x2c4/0x970 drivers/video/fbdev/core/fbcon.c:2508 con_font_set drivers/tty/vt/vt.c:4663 [inline] con_font_op+0xebc/0x1630 drivers/tty/vt/vt.c:4728 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:506 [inline] vt_ioctl+0xd7f/0x3d70 drivers/tty/vt/vt_ioctl.c:856 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888052db0000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 8016 bytes inside of 8192-byte region [ffff888052db0000, ffff888052db2000) The buggy address belongs to the page: page:000000001e8ea1a9 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x52db0 head:000000001e8ea1a9 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0001670408 ffffea00014dcc08 ffff8880aa440a00 raw: 0000000000000000 ffff888052db0000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888052db1e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888052db1e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888052db1f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888052db1f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888052db2000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================