================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:656 [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+0xbb6/0xd20 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff88805fa97a1a by task syz-executor.4/32735 CPU: 0 PID: 32735 Comm: syz-executor.4 Not tainted 5.8.0-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+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 __fb_pad_aligned_buffer include/linux/fb.h:656 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xbb6/0xd20 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x33c/0x3f0 drivers/video/fbdev/core/fbcon.c:1362 do_update_region+0x399/0x630 drivers/tty/vt/vt.c:675 redraw_screen+0x64e/0x770 drivers/tty/vt/vt.c:1034 vc_do_resize+0xef0/0x1180 drivers/tty/vt/vt.c:1325 vt_resizex drivers/tty/vt/vt_ioctl.c:814 [inline] vt_ioctl+0xeba/0x2c20 drivers/tty/vt/vt_ioctl.c:1026 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d249 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:00007f200df12c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000001c340 RCX: 000000000045d249 RDX: 0000000020000080 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007fffb1c96cef R14: 00007f200df139c0 R15: 000000000118cf4c Allocated by task 19870: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x1a8/0x320 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [inline] fbcon_set_font+0x34f/0x8b0 drivers/video/fbdev/core/fbcon.c:2673 con_font_set drivers/tty/vt/vt.c:4662 [inline] con_font_op+0xd25/0x1110 drivers/tty/vt/vt.c:4727 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:595 [inline] vt_ioctl+0x1be1/0x2c20 drivers/tty/vt/vt_ioctl.c:846 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88805fa97800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 538 bytes inside of 1024-byte region [ffff88805fa97800, ffff88805fa97c00) The buggy address belongs to the page: page:000000006872f2a0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5fa97 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea000120ddc8 ffffea0001708d08 ffff8880aa040700 raw: 0000000000000000 ffff88805fa97000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805fa97900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88805fa97980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88805fa97a00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88805fa97a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805fa97b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================