================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:655 [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 ffff8880928b6940 by task syz-executor.4/16012 CPU: 1 PID: 16012 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/0x436 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:655 [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:683 redraw_screen+0x64c/0x770 drivers/tty/vt/vt.c:1029 vc_do_resize+0x1111/0x13f0 drivers/tty/vt/vt.c:1320 vt_ioctl+0x2037/0x2670 drivers/tty/vt/vt_ioctl.c:901 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:753 __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl fs/ioctl.c:760 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cce9 Code: 2d 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 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7f94435c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000001c300 RCX: 000000000045cce9 RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffd3090768f R14: 00007f7f944369c0 R15: 000000000078bf0c Allocated by task 11807: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x17a/0x340 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] fbcon_set_font+0x34f/0x8b0 drivers/video/fbdev/core/fbcon.c:2673 con_font_set drivers/tty/vt/vt.c:4578 [inline] con_font_op+0xd25/0x1110 drivers/tty/vt/vt.c:4643 vt_ioctl+0x1180/0x2670 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:753 __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl fs/ioctl.c:760 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 11186: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x103/0x2c0 mm/slab.c:3757 load_elf_binary+0x356b/0x4831 fs/binfmt_elf.c:1207 search_binary_handler fs/exec.c:1749 [inline] exec_binprm fs/exec.c:1790 [inline] __do_execve_file+0x1652/0x2ee0 fs/exec.c:1926 do_execveat_common fs/exec.c:1980 [inline] do_execve+0x35/0x50 fs/exec.c:1997 call_usermodehelper_exec_async+0x589/0x710 kernel/umh.c:112 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff8880928b6800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 320 bytes inside of 512-byte region [ffff8880928b6800, ffff8880928b6a00) The buggy address belongs to the page: page:ffffea00024a2d80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880928b6400 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002434f48 ffffea00025f3fc8 ffff8880aa000a80 raw: ffff8880928b6400 ffff8880928b6000 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880928b6800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880928b6880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880928b6900: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880928b6980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880928b6a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================