netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. ================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:674 [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+0xbaf/0xd10 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff8880a0d2d9ad by task syz-executor.2/26874 CPU: 0 PID: 26874 Comm: syz-executor.2 Not tainted 4.19.129-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+0x1fc/0x2fe lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load1_noabort+0x88/0x90 mm/kasan/report.c:430 __fb_pad_aligned_buffer include/linux/fb.h:674 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xbaf/0xd10 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x336/0x4f0 drivers/video/fbdev/core/fbcon.c:1323 con_flush drivers/tty/vt/vt.c:2552 [inline] do_con_write+0xd0e/0x1d90 drivers/tty/vt/vt.c:2805 con_write+0x22/0xb0 drivers/tty/vt/vt.c:3138 process_output_block drivers/tty/n_tty.c:593 [inline] n_tty_write+0x3c0/0xff0 drivers/tty/n_tty.c:2331 do_tty_write drivers/tty/tty_io.c:960 [inline] tty_write+0x496/0x810 drivers/tty/tty_io.c:1044 do_loop_readv_writev fs/read_write.c:704 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_write+0x461/0x5d0 fs/read_write.c:962 vfs_writev+0x153/0x2e0 fs/read_write.c:1005 do_writev+0x136/0x330 fs/read_write.c:1040 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ca59 Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fc87a0f9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000050e3e0 RCX: 000000000045ca59 RDX: 0000000000000001 RSI: 00000000200005c0 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000d45 R14: 00000000004cb67f R15: 00007fc87a0fa6d4 Allocated by task 7487: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x3c0 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] fbcon_set_font+0x34f/0x8a0 drivers/video/fbdev/core/fbcon.c:2644 con_font_set drivers/tty/vt/vt.c:4529 [inline] con_font_op+0xd02/0x10e0 drivers/tty/vt/vt.c:4594 vt_ioctl+0x116d/0x24d0 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0x5b0/0x15c0 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 6262: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 load_elf_binary+0x2353/0x5050 fs/binfmt_elf.c:1118 search_binary_handler.part.0+0xf9/0x4e0 fs/exec.c:1655 search_binary_handler fs/exec.c:1644 [inline] exec_binprm fs/exec.c:1697 [inline] __do_execve_file+0x1357/0x2360 fs/exec.c:1819 do_execveat_common fs/exec.c:1866 [inline] do_execve+0x35/0x50 fs/exec.c:1883 __do_sys_execve fs/exec.c:1964 [inline] __se_sys_execve fs/exec.c:1959 [inline] __x64_sys_execve+0x7c/0xa0 fs/exec.c:1959 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a0d2d7c0 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 493 bytes inside of 512-byte region [ffff8880a0d2d7c0, ffff8880a0d2d9c0) The buggy address belongs to the page: page:ffffea0002834b40 count:1 mapcount:0 mapping:ffff88812c39c940 index:0x0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffffea00026e6408 ffffea0002182fc8 ffff88812c39c940 raw: 0000000000000000 ffff8880a0d2d040 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a0d2d880: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff8880a0d2d900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a0d2d980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a0d2da00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff8880a0d2da80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================