==================================================================
BUG: KASAN: vmalloc-out-of-bounds in fast_imageblit drivers/video/fbdev/core/sysimgblt.c:257 [inline]
BUG: KASAN: vmalloc-out-of-bounds in sys_imageblit+0x1bac/0x25d0 drivers/video/fbdev/core/sysimgblt.c:323
Write of size 4 at addr ffffc90003fd9000 by task syz.8.1731/12120
CPU: 0 PID: 12120 Comm: syz.8.1731 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xa8/0x210 mm/kasan/report.c:468
kasan_report+0x117/0x150 mm/kasan/report.c:581
fast_imageblit drivers/video/fbdev/core/sysimgblt.c:257 [inline]
sys_imageblit+0x1bac/0x25d0 drivers/video/fbdev/core/sysimgblt.c:323
drm_fbdev_generic_defio_imageblit+0x2c/0x110 drivers/gpu/drm/drm_fbdev_generic.c:37
soft_cursor+0xa01/0xc30 drivers/video/fbdev/core/softcursor.c:74
bit_cursor+0x16dd/0x1f60 drivers/video/fbdev/core/bitblit.c:409
hide_cursor+0x7f/0x320 drivers/tty/vt/vt.c:855
putconsxy+0x2f/0x540 drivers/tty/vt/vt.c:4735
vcs_write_buf drivers/tty/vt/vc_screen.c:535 [inline]
vcs_write+0xa51/0x1290 drivers/tty/vt/vc_screen.c:688
vfs_write+0x299/0x9a0 fs/read_write.c:582
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbc9299f559
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:00007fbc9394e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbc92c25fa0 RCX: 00007fbc9299f559
RDX: 0000000000001006 RSI: 0000200000000580 RDI: 0000000000000003
RBP: 00007fbc92a36b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbc92c26038 R14: 00007fbc92c25fa0 R15: 00007ffcf5bf8b08
The buggy address belongs to a vmalloc virtual mapping
Memory state around the buggy address:
ffffc90003fd8f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc90003fd8f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc90003fd9000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
^
ffffc90003fd9080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc90003fd9100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================
BUG: unable to handle page fault for address: ffffc90003fd9000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 18c00067 P4D 18c00067 PUD 1aa7b067 PMD 140ba5067 PTE 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 12120 Comm: syz.8.1731 Tainted: G B syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:fast_imageblit drivers/video/fbdev/core/sysimgblt.c:257 [inline]
RIP: 0010:sys_imageblit+0x1895/0x25d0 drivers/video/fbdev/core/sysimgblt.c:323
Code: 46 ff c1 e8 07 21 d0 8b 9c 84 c0 00 00 00 4c 8b 7c 24 30 4b 8d 3c 37 48 89 f8 48 c1 e8 03 0f b6 04 08 84 c0 0f 85 f8 02 00 00 <43> 89 1c 37 0f b6 46 ff c1 e8 06 21 d0 8b 9c 84 c0 00 00 00 4b 8d
RSP: 0018:ffffc9000cda76c0 EFLAGS: 00010286
RAX: ffff888077325a01 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: ffff88801cf1d4a1 RDI: 0000000000012c0a
RBP: ffffc9000cda7838 R08: ffffffff9111df87 R09: 1ffffffff2223bf0
R10: dffffc0000000000 R11: fffffbfff2223bf1 R12: 0000000000000008
R13: 1ffff110039e3a94 R14: 0000000000000000 R15: ffffc90003fd9000
FS: 00007fbc9394e6c0(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90003fd9000 CR3: 00000000500d7000 CR4: 00000000003506f0
Call Trace:
drm_fbdev_generic_defio_imageblit+0x2c/0x110 drivers/gpu/drm/drm_fbdev_generic.c:37
soft_cursor+0xa01/0xc30 drivers/video/fbdev/core/softcursor.c:74
bit_cursor+0x16dd/0x1f60 drivers/video/fbdev/core/bitblit.c:409
hide_cursor+0x7f/0x320 drivers/tty/vt/vt.c:855
putconsxy+0x2f/0x540 drivers/tty/vt/vt.c:4735
vcs_write_buf drivers/tty/vt/vc_screen.c:535 [inline]
vcs_write+0xa51/0x1290 drivers/tty/vt/vc_screen.c:688
vfs_write+0x299/0x9a0 fs/read_write.c:582
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbc9299f559
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:00007fbc9394e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbc92c25fa0 RCX: 00007fbc9299f559
RDX: 0000000000001006 RSI: 0000200000000580 RDI: 0000000000000003
RBP: 00007fbc92a36b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbc92c26038 R14: 00007fbc92c25fa0 R15: 00007ffcf5bf8b08
Modules linked in:
CR2: ffffc90003fd9000
---[ end trace 0000000000000000 ]---
RIP: 0010:fast_imageblit drivers/video/fbdev/core/sysimgblt.c:257 [inline]
RIP: 0010:sys_imageblit+0x1895/0x25d0 drivers/video/fbdev/core/sysimgblt.c:323
Code: 46 ff c1 e8 07 21 d0 8b 9c 84 c0 00 00 00 4c 8b 7c 24 30 4b 8d 3c 37 48 89 f8 48 c1 e8 03 0f b6 04 08 84 c0 0f 85 f8 02 00 00 <43> 89 1c 37 0f b6 46 ff c1 e8 06 21 d0 8b 9c 84 c0 00 00 00 4b 8d
RSP: 0018:ffffc9000cda76c0 EFLAGS: 00010286
RAX: ffff888077325a01 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: ffff88801cf1d4a1 RDI: 0000000000012c0a
RBP: ffffc9000cda7838 R08: ffffffff9111df87 R09: 1ffffffff2223bf0
R10: dffffc0000000000 R11: fffffbfff2223bf1 R12: 0000000000000008
R13: 1ffff110039e3a94 R14: 0000000000000000 R15: ffffc90003fd9000
FS: 00007fbc9394e6c0(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90003fd9000 CR3: 00000000500d7000 CR4: 00000000003506f0
----------------
Code disassembly (best guess):
0: 46 ff c1 rex.RX inc %ecx
3: e8 07 21 d0 8b call 0x8bd0210f
8: 9c pushf
9: 84 c0 test %al,%al
b: 00 00 add %al,(%rax)
d: 00 4c 8b 7c add %cl,0x7c(%rbx,%rcx,4)
11: 24 30 and $0x30,%al
13: 4b 8d 3c 37 lea (%r15,%r14,1),%rdi
17: 48 89 f8 mov %rdi,%rax
1a: 48 c1 e8 03 shr $0x3,%rax
1e: 0f b6 04 08 movzbl (%rax,%rcx,1),%eax
22: 84 c0 test %al,%al
24: 0f 85 f8 02 00 00 jne 0x322
* 2a: 43 89 1c 37 mov %ebx,(%r15,%r14,1) <-- trapping instruction
2e: 0f b6 46 ff movzbl -0x1(%rsi),%eax
32: c1 e8 06 shr $0x6,%eax
35: 21 d0 and %edx,%eax
37: 8b 9c 84 c0 00 00 00 mov 0xc0(%rsp,%rax,4),%ebx
3e: 4b rex.WXB
3f: 8d .byte 0x8d