================================================================== 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+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff888088da08fe by task syz-executor.3/19844 CPU: 0 PID: 19844 Comm: syz-executor.3 Not tainted 5.9.0-rc1-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+0x1f0/0x31e 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+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x790/0xaf0 drivers/video/fbdev/core/fbcon.c:1362 do_update_region+0x462/0x620 drivers/tty/vt/vt.c:675 redraw_screen+0xa25/0x1420 drivers/tty/vt/vt.c:1034 vc_do_resize+0x11ab/0x1790 drivers/tty/vt/vt.c:1325 vt_resizex drivers/tty/vt/vt_ioctl.c:814 [inline] vt_ioctl+0x3032/0x3c60 drivers/tty/vt/vt_ioctl.c:1026 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 RIP: 0033:0x45d239 Code: 5d 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f9a911dec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000001c340 RCX: 000000000045d239 RDX: 0000000020000240 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007fff8fb302af R14: 00007f9a911df9c0 R15: 000000000118cf4c Allocated by task 17425: 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:3655 [inline] __kmalloc+0x218/0x320 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [inline] fbcon_set_font+0x2c4/0x970 drivers/video/fbdev/core/fbcon.c:2673 con_font_set drivers/tty/vt/vt.c:4662 [inline] con_font_op+0xebc/0x1630 drivers/tty/vt/vt.c:4727 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:506 [inline] vt_ioctl+0xd7f/0x3c60 drivers/tty/vt/vt_ioctl.c:846 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 ffff888088da0000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 254 bytes to the right of 2048-byte region [ffff888088da0000, ffff888088da0800) The buggy address belongs to the page: page:000000000ffa5da0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x88da0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00027bb8c8 ffffea000258d108 ffff8880aa440800 raw: 0000000000000000 ffff888088da0000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888088da0780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888088da0800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888088da0880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888088da0900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888088da0980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================