================================================================== BUG: KASAN: out-of-bounds in csd_lock_record+0xcb/0xe0 kernel/smp.c:118 Read of size 8 at addr ffffc90001867b90 by task syz-executor.5/11228 CPU: 0 PID: 11228 Comm: syz-executor.5 Not tainted 5.8.0-rc3-next-20200703-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+0x5/0x436 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 csd_lock_record+0xcb/0xe0 kernel/smp.c:118 flush_smp_call_function_queue+0x285/0x730 kernel/smp.c:391 __sysvec_call_function_single+0x98/0x490 arch/x86/kernel/smp.c:248 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_call_function_single+0xe0/0x120 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:604 RIP: 0010:slow_down_io arch/x86/include/asm/paravirt.h:42 [inline] RIP: 0010:inb_p arch/x86/include/asm/io.h:334 [inline] RIP: 0010:vga_io_r include/video/vga.h:204 [inline] RIP: 0010:vga_io_rgfx include/video/vga.h:389 [inline] RIP: 0010:selectmask drivers/video/fbdev/vga16fb.c:132 [inline] RIP: 0010:vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1165 [inline] RIP: 0010:vga16fb_imageblit+0x9c3/0x2210 drivers/video/fbdev/vga16fb.c:1260 Code: c7 c2 f8 fd b4 89 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 f8 14 00 00 ff 15 8b d1 ec 05 ba cf 03 00 00 ec <48> c7 c2 f8 fd b4 89 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 RSP: 0018:ffffc90001746ec0 EFLAGS: 00000246 RAX: dffffc00000000ff RBX: 0000000000000007 RCX: ffffc90013b94000 RDX: 00000000000003cf RSI: ffffffff83c82a12 RDI: ffffc90001747058 RBP: ffffc9000174704c R08: 0000000000000013 R09: 0000000000000037 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8132b3d0 R13: ffff8882188a0000 R14: ffffc90001747068 R15: ffffc90001747048 bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline] bit_putcs+0x6e1/0xd20 drivers/video/fbdev/core/bitblit.c:188 fbcon_putcs+0x33c/0x3f0 drivers/video/fbdev/core/fbcon.c:1362 fbcon_redraw.constprop.0+0x41a/0x4b0 drivers/video/fbdev/core/fbcon.c:1840 fbcon_scroll+0x1dde/0x3600 drivers/video/fbdev/core/fbcon.c:1978 con_scroll+0x5b9/0x6d0 drivers/tty/vt/vt.c:629 lf+0x26b/0x2c0 drivers/tty/vt/vt.c:1483 do_con_trol+0x20f/0x51e0 drivers/tty/vt/vt.c:2161 do_con_write+0xb7f/0x1d70 drivers/tty/vt/vt.c:2899 con_write+0x22/0xb0 drivers/tty/vt/vt.c:3243 do_output_char+0x5de/0x850 drivers/tty/n_tty.c:447 process_output drivers/tty/n_tty.c:514 [inline] n_tty_write+0x481/0xf80 drivers/tty/n_tty.c:2345 do_tty_write drivers/tty/tty_io.c:962 [inline] tty_write+0x4d9/0x870 drivers/tty/tty_io.c:1046 __vfs_write+0x76/0x100 fs/read_write.c:495 __kernel_write+0x11c/0x3a0 fs/read_write.c:516 write_pipe_buf+0x153/0x1f0 fs/splice.c:799 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x3dc/0x830 fs/splice.c:626 splice_from_pipe fs/splice.c:661 [inline] default_file_splice_write fs/splice.c:811 [inline] do_splice_from fs/splice.c:847 [inline] direct_splice_actor+0x228/0x2f0 fs/splice.c:1016 splice_direct_to_actor+0x38c/0x980 fs/splice.c:971 do_splice_direct+0x1b3/0x280 fs/splice.c:1059 do_sendfile+0x559/0xc30 fs/read_write.c:1521 __do_sys_sendfile64 fs/read_write.c:1582 [inline] __se_sys_sendfile64 fs/read_write.c:1568 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1568 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:367 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cb29 Code: Bad RIP value. RSP: 002b:00007f475caf2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000004fd720 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000007 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0800000080004105 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000902 R14: 00000000004cbe0a R15: 00007f475caf36d4 Memory state around the buggy address: ffffc90001867a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 ffffc90001867b00: f1 f1 f1 f1 f1 01 f2 00 00 f2 f2 05 f3 f3 f3 00 >ffffc90001867b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffffc90001867c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc90001867c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================