===================================================== BUG: KMSAN: uninit-value in writeb arch/x86/include/asm/io.h:65 [inline] BUG: KMSAN: uninit-value in vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1176 [inline] BUG: KMSAN: uninit-value in vga16fb_imageblit+0x125e/0x20c0 drivers/video/fbdev/vga16fb.c:1260 CPU: 1 PID: 17719 Comm: syz-executor.1 Not tainted 5.8.0-rc5-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+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 writeb arch/x86/include/asm/io.h:65 [inline] vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1176 [inline] vga16fb_imageblit+0x125e/0x20c0 drivers/video/fbdev/vga16fb.c:1260 bit_putcs+0x3039/0x3390 drivers/video/fbdev/core/bitblit.c:105 fbcon_putcs+0x121c/0x1250 drivers/video/fbdev/core/fbcon.c:1362 fbcon_redraw+0x53a/0x8e0 drivers/video/fbdev/core/fbcon.c:1825 fbcon_scroll+0x1cbb/0x9de0 drivers/video/fbdev/core/fbcon.c:1978 con_scroll+0xd44/0x11b0 drivers/tty/vt/vt.c:637 lf drivers/tty/vt/vt.c:1483 [inline] do_con_write+0x6031/0x15460 drivers/tty/vt/vt.c:2781 con_write+0x8e/0xe0 drivers/tty/vt/vt.c:3159 process_output_block drivers/tty/n_tty.c:595 [inline] n_tty_write+0x167a/0x2230 drivers/tty/n_tty.c:2333 do_tty_write drivers/tty/tty_io.c:962 [inline] tty_write+0x9fb/0x1610 drivers/tty/tty_io.c:1046 __kernel_write+0x3cf/0x1430 fs/read_write.c:528 write_pipe_buf+0x1c0/0x270 fs/splice.c:799 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x5e3/0xff0 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+0x39f/0x570 fs/splice.c:1016 splice_direct_to_actor+0xa3a/0x14e0 fs/splice.c:971 do_splice_direct+0x39e/0x5f0 fs/splice.c:1059 do_sendfile+0x141a/0x2420 fs/read_write.c:1540 __do_compat_sys_sendfile fs/read_write.c:1622 [inline] __se_compat_sys_sendfile+0x3d9/0x4e0 fs/read_write.c:1605 __ia32_compat_sys_sendfile+0x56/0x70 fs/read_write.c:1605 do_syscall_32_irqs_on arch/x86/entry/common.c:430 [inline] __do_fast_syscall_32+0x2af/0x480 arch/x86/entry/common.c:477 do_fast_syscall_32+0x6b/0xd0 arch/x86/entry/common.c:505 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:554 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf7f91549 Code: Bad RIP value. RSP: 002b:00000000f558b0cc EFLAGS: 00000296 ORIG_RAX: 00000000000000bb RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000004 RDX: 0000000000000000 RSI: 0000000080004103 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165 __fb_pad_aligned_buffer include/linux/fb.h:655 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0x2709/0x3390 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x121c/0x1250 drivers/video/fbdev/core/fbcon.c:1362 fbcon_redraw+0x53a/0x8e0 drivers/video/fbdev/core/fbcon.c:1825 fbcon_scroll+0x1cbb/0x9de0 drivers/video/fbdev/core/fbcon.c:1978 con_scroll+0xd44/0x11b0 drivers/tty/vt/vt.c:637 lf drivers/tty/vt/vt.c:1483 [inline] do_con_write+0x6031/0x15460 drivers/tty/vt/vt.c:2781 con_write+0x8e/0xe0 drivers/tty/vt/vt.c:3159 process_output_block drivers/tty/n_tty.c:595 [inline] n_tty_write+0x167a/0x2230 drivers/tty/n_tty.c:2333 do_tty_write drivers/tty/tty_io.c:962 [inline] tty_write+0x9fb/0x1610 drivers/tty/tty_io.c:1046 __kernel_write+0x3cf/0x1430 fs/read_write.c:528 write_pipe_buf+0x1c0/0x270 fs/splice.c:799 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x5e3/0xff0 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+0x39f/0x570 fs/splice.c:1016 splice_direct_to_actor+0xa3a/0x14e0 fs/splice.c:971 do_splice_direct+0x39e/0x5f0 fs/splice.c:1059 do_sendfile+0x141a/0x2420 fs/read_write.c:1540 __do_compat_sys_sendfile fs/read_write.c:1622 [inline] __se_compat_sys_sendfile+0x3d9/0x4e0 fs/read_write.c:1605 __ia32_compat_sys_sendfile+0x56/0x70 fs/read_write.c:1605 do_syscall_32_irqs_on arch/x86/entry/common.c:430 [inline] __do_fast_syscall_32+0x2af/0x480 arch/x86/entry/common.c:477 do_fast_syscall_32+0x6b/0xd0 arch/x86/entry/common.c:505 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:554 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80 slab_alloc_node mm/slub.c:2839 [inline] slab_alloc mm/slub.c:2848 [inline] __kmalloc+0x312/0x410 mm/slub.c:3911 kmalloc include/linux/slab.h:560 [inline] fbcon_set_font+0x5ad/0xfb0 drivers/video/fbdev/core/fbcon.c:2673 con_font_set drivers/tty/vt/vt.c:4571 [inline] con_font_op+0x1e59/0x2290 drivers/tty/vt/vt.c:4636 vt_ioctl+0x99e/0x6a40 drivers/tty/vt/vt_ioctl.c:917 vt_compat_ioctl+0x59b/0x1040 drivers/tty/vt/vt_ioctl.c:1242 tty_compat_ioctl+0x74b/0x1660 drivers/tty/tty_io.c:2847 __do_compat_sys_ioctl fs/ioctl.c:847 [inline] __se_compat_sys_ioctl+0x55f/0x1100 fs/ioctl.c:798 __ia32_compat_sys_ioctl+0x4a/0x70 fs/ioctl.c:798 do_syscall_32_irqs_on arch/x86/entry/common.c:430 [inline] __do_fast_syscall_32+0x2af/0x480 arch/x86/entry/common.c:477 do_fast_syscall_32+0x6b/0xd0 arch/x86/entry/common.c:505 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:554 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c =====================================================