================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:663 [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+0xab7/0xc30 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff888090a067c2 by task syz-executor.1/17869 CPU: 1 PID: 17869 Comm: syz-executor.1 Not tainted 4.14.191-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load1_noabort+0x68/0x70 mm/kasan/report.c:427 __fb_pad_aligned_buffer include/linux/fb.h:663 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xab7/0xc30 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x2fe/0x480 drivers/video/fbdev/core/fbcon.c:1301 do_update_region+0x34b/0x5b0 drivers/tty/vt/vt.c:373 redraw_screen+0x56e/0x790 drivers/tty/vt/vt.c:705 vc_do_resize+0xc20/0xe30 drivers/tty/vt/vt.c:973 vt_ioctl+0x19f7/0x1ea0 drivers/tty/vt/vt_ioctl.c:901 tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45ccd9 RSP: 002b:00007fa4f52ecc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000001c300 RCX: 000000000045ccd9 RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffc7aceb2ef R14: 00007fa4f52ed9c0 R15: 000000000078bf0c Allocated by task 8645: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15a/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] fbcon_set_font+0x2fb/0x7c0 drivers/video/fbdev/core/fbcon.c:2621 con_font_set drivers/tty/vt/vt.c:4189 [inline] con_font_op+0xb69/0xf60 drivers/tty/vt/vt.c:4254 vt_ioctl+0xd91/0x1ea0 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 7867: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 kvfree+0x45/0x50 mm/util.c:416 __free_fdtable fs/file.c:36 [inline] put_files_struct fs/file.c:425 [inline] put_files_struct+0x259/0x340 fs/file.c:418 exit_files+0x7e/0xa0 fs/file.c:450 do_exit+0x9dc/0x27f0 kernel/exit.c:860 do_group_exit+0x100/0x2e0 kernel/exit.c:962 get_signal+0x38d/0x1ca0 kernel/signal.c:2423 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff888090a060c0 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 1794 bytes inside of 2048-byte region [ffff888090a060c0, ffff888090a068c0) The buggy address belongs to the page: page:ffffea0002428180 count:1 mapcount:0 mapping:ffff888090a060c0 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffff888090a060c0 0000000000000000 0000000100000003 raw: ffffea0002846820 ffffea000238c3a0 ffff88812fe52c40 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888090a06680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888090a06700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888090a06780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888090a06800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888090a06880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================