================================================================== BUG: KASAN: vmalloc-out-of-bounds in fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_bitblit drivers/video/fbdev/core/fb_imageblit.h:153 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_bitmap1x_imageblit drivers/video/fbdev/core/fb_imageblit.h:275 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:477 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] BUG: KASAN: vmalloc-out-of-bounds in sys_imageblit+0x1b3f/0x1e60 drivers/video/fbdev/core/sysimgblt.c:24 Write of size 8 at addr ffffc90005749000 by task syz.3.5313/21166 CPU: 1 UID: 0 PID: 21166 Comm: syz.3.5313 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] fb_bitblit drivers/video/fbdev/core/fb_imageblit.h:153 [inline] fb_bitmap1x_imageblit drivers/video/fbdev/core/fb_imageblit.h:275 [inline] fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:477 [inline] fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] sys_imageblit+0x1b3f/0x1e60 drivers/video/fbdev/core/sysimgblt.c:24 drm_fbdev_shmem_defio_imageblit+0x20/0x130 drivers/gpu/drm/drm_fbdev_shmem.c:38 bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:138 [inline] bit_putcs+0x90f/0xde0 drivers/video/fbdev/core/bitblit.c:187 fbcon_putcs+0x384/0x4a0 drivers/video/fbdev/core/fbcon.c:1327 do_update_region+0x2e6/0x3f0 drivers/tty/vt/vt.c:627 redraw_screen+0x63f/0x760 drivers/tty/vt/vt.c:979 fbcon_blank+0x652/0xd20 drivers/video/fbdev/core/fbcon.c:2271 do_unblank_screen+0x2c6/0x560 drivers/tty/vt/vt.c:4645 unblank_screen drivers/tty/vt/vt.c:4665 [inline] poke_blanked_console+0x24c/0x2d0 drivers/tty/vt/vt.c:4700 vc_selection drivers/tty/vt/selection.c:344 [inline] set_selection_kernel+0xb8/0x14a0 drivers/tty/vt/selection.c:382 set_selection_user+0xe8/0x140 drivers/tty/vt/selection.c:208 tioclinux+0x2b1/0x640 drivers/tty/vt/vt.c:3430 vt_ioctl+0x1fdf/0x30a0 drivers/tty/vt/vt_ioctl.c:761 tty_ioctl+0x661/0x1680 drivers/tty/tty_io.c:2792 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0ead78ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0eae5e5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f0ead9c5fa0 RCX: 00007f0ead78ebe9 RDX: 0000200000000100 RSI: 000000000000541c RDI: 0000000000000004 RBP: 00007f0ead811e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0ead9c6038 R14: 00007f0ead9c5fa0 R15: 00007ffc5ba18048 The buggy address belongs to a 0-page vmalloc region starting at 0xffffc90005449000 allocated at drm_gem_shmem_vmap_locked+0x561/0x7e0 drivers/gpu/drm/drm_gem_shmem_helper.c:371 Memory state around the buggy address: ffffc90005748f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc90005748f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc90005749000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc90005749080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90005749100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ==================================================================