================================================================== 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 bitfill drivers/video/fbdev/core/fb_fillrect.h:134 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_fillrect_static drivers/video/fbdev/core/fb_fillrect.h:220 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_fillrect drivers/video/fbdev/core/fb_fillrect.h:279 [inline] BUG: KASAN: vmalloc-out-of-bounds in sys_fillrect+0x15d4/0x17b0 drivers/video/fbdev/core/sysfillrect.c:22 Write of size 8 at addr ffffc90004c59000 by task syz.2.558/7930 CPU: 3 UID: 0 PID: 7930 Comm: syz.2.558 Not tainted 6.16.0-rc3-syzkaller-00044-g7595b66ae9de #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:408 [inline] print_report+0xcd/0x680 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] bitfill drivers/video/fbdev/core/fb_fillrect.h:134 [inline] fb_fillrect_static drivers/video/fbdev/core/fb_fillrect.h:220 [inline] fb_fillrect drivers/video/fbdev/core/fb_fillrect.h:279 [inline] sys_fillrect+0x15d4/0x17b0 drivers/video/fbdev/core/sysfillrect.c:22 drm_fbdev_shmem_defio_fillrect+0x22/0x140 drivers/gpu/drm/drm_fbdev_shmem.c:37 bit_clear_margins+0x2f7/0x4c0 drivers/video/fbdev/core/bitblit.c:231 fbcon_clear_margins.constprop.0+0x1d3/0x290 drivers/video/fbdev/core/fbcon.c:1325 fbcon_switch+0xa01/0x14c0 drivers/video/fbdev/core/fbcon.c:2196 redraw_screen+0x2c1/0x760 drivers/tty/vt/vt.c:965 fbcon_set_disp+0x7d4/0xe40 drivers/video/fbdev/core/fbcon.c:1418 con2fb_init_display drivers/video/fbdev/core/fbcon.c:816 [inline] set_con2fb_map+0x703/0x1060 drivers/video/fbdev/core/fbcon.c:889 fbcon_set_con2fb_map_ioctl+0x16c/0x220 drivers/video/fbdev/core/fbcon.c:3118 do_fb_ioctl+0x328/0x7e0 drivers/video/fbdev/core/fb_chrdev.c:138 fb_compat_ioctl+0x55e/0x670 drivers/video/fbdev/core/fb_chrdev.c:293 __do_compat_sys_ioctl fs/ioctl.c:1005 [inline] __se_compat_sys_ioctl fs/ioctl.c:948 [inline] __ia32_compat_sys_ioctl+0x23f/0x370 fs/ioctl.c:948 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf70de579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f50ce55c EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000004610 RDX: 00000000800000c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 The buggy address belongs to the virtual mapping at [ffffc90004959000, ffffc90004c5a000) created by: drm_gem_shmem_vmap_locked+0x4bc/0x720 drivers/gpu/drm/drm_gem_shmem_helper.c:369 Memory state around the buggy address: ffffc90004c58f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc90004c58f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc90004c59000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc90004c59080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90004c59100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi