From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f205.google.com (mail-il1-f205.google.com [209.85.166.205]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 16A491917F0 for ; Sun, 2 Nov 2025 21:10:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.205 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762117835; cv=none; b=MZcjdMNP5C9nrYh38H5GVyp7aEUq6loQK0YCNeMxvFy6zdgaKNo86uTeuv1Z46TSkFBGgiJ02ALPQWCp/sXo94FE2pNP9piWR1DZjixSxJr8xv9vsuBkugqcbNwV6wGkPbhDdlMA2D5iG4T59JPGuaVK7qE1K5UXSFNY/D3858E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762117835; c=relaxed/simple; bh=hHOeeEihzzDfg1Xo6u6zZ2eGJFu1etPWu2Vm+y9Jth4=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=gMjo9UgjFmpONO+oTHgE3fUdoO5C8qctyADp6AzuBD095eEqFdsLHtb1XA6/78BOvswvZlfruWN55KdO4uYktI+ZoMvgdxZDIh73Vs4F18G8aedVX91R2ghNQGMm+vqQVnv4Rklj8tvlgduX7jjSbK0lZ+AeqnGvaQHMvkI4ZCQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.205 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-il1-f205.google.com with SMTP id e9e14a558f8ab-433316b78f4so1393035ab.3 for ; Sun, 02 Nov 2025 13:10:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762117832; x=1762722632; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=3r4tNEJZqNR7jvnaf7lJZd2h8YwAodUy8epKeDGKL8M=; b=qks+LskE8teGZIa7h7mnMopmoMZ2BMRGxZWKCrATkazF+NOlv7FS4LOaKDyxIVYqH/ nVwj4XUZUtc0RzijcWodhTi9prXbd0V/1a4eWxR2DR0grMOzc1jJxexHkOXOiw88TXkX +QGpkQoMFaNDyKE8elhdqW6QQa6vu6Q+KkH6AcS+1VZqRQJI5Yme4KF4mrjiJigqjIEH LTgpoTtLISAt6QcafWWxNpkZnRZSv2r/rk1VuWVybNjJwK5rI6F8v/Q2UymeztWoyvny F3Yg0ljaR3beW6y3bAuNbvBKTLU78ufxc41mlWMlaDGGVvd72Yb5sgTJhHPlBIufotv2 l7zA== X-Forwarded-Encrypted: i=1; AJvYcCVFmI3B0LgYJaSre15SfV8LwD7zoZaPE4LQfmvPDWExYMtXFd6m08YhRAb+nz091AZ5yFvUJqcFPyrCgg==@vger.kernel.org X-Gm-Message-State: AOJu0YzMeHogma0/MwvpUcR1fjFcETtwqjJW2/SR0EQecckSzWSOWAYG BpbS1OKdNnGiHdrEYCsuSuZQ8IKyYCvxxxk8KiQCuZxhJav7ScAi7nFTPS08x1AG0OxsSaSObCF JoO2kArxpMTIqu/v6gKDbLaP5Eg1ATYhzAoGLAMhcBSZXDhWMgqEndtlZojk= X-Google-Smtp-Source: AGHT+IEqch9T1rUJ4zmGL76ryOqcCV26GrGnOehnclE3lWkRPkCkLqATTcyvFnUrKGBOLj8Tji95+WoXRgANuKRr2nfZX0/Qrafy Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1849:b0:433:3035:7426 with SMTP id e9e14a558f8ab-4333035764fmr19518625ab.16.1762117832219; Sun, 02 Nov 2025 13:10:32 -0800 (PST) Date: Sun, 02 Nov 2025 13:10:32 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6907c8c8.a70a0220.37351b.0012.GAE@google.com> Subject: [syzbot] [fbdev?] KASAN: vmalloc-out-of-bounds Write in imageblit (6) From: syzbot To: deller@gmx.de, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, simona@ffwll.ch, soci@c64.rulez.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 691d401c7e0e Merge tag 'spi-fix-v6.18-rc3' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14607932580000 kernel config: https://syzkaller.appspot.com/x/.config?x=19d831c6d0386a9c dashboard link: https://syzkaller.appspot.com/bug?extid=5a40432dfe8f86ee657a compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/5eaccda03e4f/disk-691d401c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/0df5294a69bc/vmlinux-691d401c.xz kernel image: https://storage.googleapis.com/syzbot-assets/f4f242731772/bzImage-691d401c.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+5a40432dfe8f86ee657a@syzkaller.appspotmail.com ================================================================== 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+0x1a6f/0x1e60 drivers/video/fbdev/core/sysimgblt.c:24 Write of size 8 at addr ffffc90003e99280 by task kworker/0:2/781 CPU: 0 UID: 0 PID: 781 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_power_efficient fb_flashcursor 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_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+0x1a6f/0x1e60 drivers/video/fbdev/core/sysimgblt.c:24 drm_fbdev_shmem_defio_imageblit+0x20/0x130 drivers/gpu/drm/drm_fbdev_shmem.c:38 soft_cursor+0x524/0xa10 drivers/video/fbdev/core/softcursor.c:74 bit_cursor+0xe8c/0x17e0 drivers/video/fbdev/core/bitblit.c:395 fb_flashcursor drivers/video/fbdev/core/fbcon.c:401 [inline] fb_flashcursor+0x310/0x400 drivers/video/fbdev/core/fbcon.c:370 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to a vmalloc virtual mapping Memory state around the buggy address: ffffc90003e99180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90003e99200: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 >ffffc90003e99280: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc90003e99300: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90003e99380: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup