================================================================== 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 ffff8880ae5e9890 by task syz-executor.5/30948 CPU: 0 PID: 30948 Comm: syz-executor.5 Not tainted 4.14.218-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+0x1b2/0x281 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x191 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:1247 do_update_region+0x34b/0x5b0 drivers/tty/vt/vt.c:373 invert_screen+0x294/0x550 drivers/tty/vt/vt.c:490 highlight drivers/tty/vt/selection.c:55 [inline] clear_selection drivers/tty/vt/selection.c:81 [inline] clear_selection+0x48/0x60 drivers/tty/vt/selection.c:77 vc_do_resize+0xb86/0xe00 drivers/tty/vt/vt.c:896 vt_ioctl+0x1884/0x1d50 drivers/tty/vt/vt_ioctl.c:905 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: 0033:0x465b09 RSP: 002b:00007f62271e2188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000020000080 RSI: 000000000000560a RDI: 0000000000000003 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffdafe6eeaf R14: 00007f62271e2300 R15: 0000000000022000 Allocated by task 11284: 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:2456 con_font_set drivers/tty/vt/vt.c:4190 [inline] con_font_op+0x9e8/0xdb0 drivers/tty/vt/vt.c:4234 vt_ioctl+0xd5d/0x1d50 drivers/tty/vt/vt_ioctl.c:938 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 10591: 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 __rcu_reclaim kernel/rcu/rcu.h:195 [inline] rcu_do_batch kernel/rcu/tree.c:2699 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline] rcu_process_callbacks+0x780/0x1180 kernel/rcu/tree.c:2946 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 The buggy address belongs to the object at ffff8880ae5e9780 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 272 bytes inside of 512-byte region [ffff8880ae5e9780, ffff8880ae5e9980) The buggy address belongs to the page: page:ffffea0002b97a40 count:1 mapcount:0 mapping:ffff8880ae5e9000 index:0x0 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff8880ae5e9000 0000000000000000 0000000100000006 raw: ffffea0002b908e0 ffffea00029965e0 ffff88813fe80940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880ae5e9780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880ae5e9800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880ae5e9880: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880ae5e9900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880ae5e9980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================