Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f91aab9f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f91aa015fa0 RCX: 00007f91a9d9bf79 RDX: 0000000000000081 RSI: 0000200000000000 RDI: 0000000000000003 RBP: 00007f91aab9f090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f91aa016038 R14: 00007f91aa015fa0 R15: 00007ffdf7cadd18 ================================================================== 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_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:364 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [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+0x19fb/0x1d60 drivers/video/fbdev/core/sysimgblt.c:24 Write of size 8 at addr ffffc90003f49fc0 by task syz.1.5120/4158 CPU: 0 UID: 0 PID: 4158 Comm: syz.1.5120 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595 fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] fb_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:364 [inline] fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [inline] fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] sys_imageblit+0x19fb/0x1d60 drivers/video/fbdev/core/sysimgblt.c:24 drm_fbdev_shmem_defio_imageblit+0x20/0x130 drivers/gpu/drm/drm_fbdev_shmem.c:39 cw_putcs_aligned drivers/video/fbdev/core/fbcon_cw.c:110 [inline] cw_putcs+0x918/0xbb0 drivers/video/fbdev/core/fbcon_cw.c:158 fbcon_putcs+0x3b2/0x480 drivers/video/fbdev/core/fbcon.c:1344 do_update_region+0x2cf/0x3f0 drivers/tty/vt/vt.c:622 redraw_screen+0x63f/0x760 drivers/tty/vt/vt.c:974 fbcon_modechanged+0x467/0x700 drivers/video/fbdev/core/fbcon.c:2699 fbcon_rotate drivers/video/fbdev/core/fbcon.c:231 [inline] rotate_store+0x258/0x2f0 drivers/video/fbdev/core/fbcon.c:3208 dev_attr_store+0x58/0x80 drivers/base/core.c:2437 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1070 fs/read_write.c:688 ksys_write+0x12a/0x250 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f91a9d9bf79 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f91aab9f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f91aa015fa0 RCX: 00007f91a9d9bf79 RDX: 0000000000000081 RSI: 0000200000000000 RDI: 0000000000000003 RBP: 00007f91aab9f090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f91aa016038 R14: 00007f91aa015fa0 R15: 00007ffdf7cadd18 The buggy address belongs to a vmalloc virtual mapping Memory state around the buggy address: ffffc90003f49e80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90003f49f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 >ffffc90003f49f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc90003f4a000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90003f4a080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ================================================================== ---------------- Code disassembly (best guess): 0: ff c3 inc %ebx 2: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 9: 00 00 00 c: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 11: 48 89 f8 mov %rdi,%rax 14: 48 89 f7 mov %rsi,%rdi 17: 48 89 d6 mov %rdx,%rsi 1a: 48 89 ca mov %rcx,%rdx 1d: 4d 89 c2 mov %r8,%r10 20: 4d 89 c8 mov %r9,%r8 23: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 28: 0f 05 syscall * 2a: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 30: 73 01 jae 0x33 32: c3 ret 33: 48 c7 c1 e8 ff ff ff mov $0xffffffffffffffe8,%rcx 3a: f7 d8 neg %eax 3c: 64 89 01 mov %eax,%fs:(%rcx) 3f: 48 rex.W