From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f207.google.com (mail-il1-f207.google.com [209.85.166.207]) (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 1224024290D for ; Tue, 19 Aug 2025 15:42:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755618154; cv=none; b=ZWxVSQuxYrgfhPnsoN8eNR/sY4rr/BPesueQI6Zy23alfgpTy+fpc1tGSDPrvWbP3Um3zn5D8Y0hwzIUZeg2gcVmeaRcnCI4VxyNagoP3qh5zFMkSTzQpHR+LSodDrKZOPYh8pw6xJCtmr/dCa5gi2kofh023SgPsHz2c6Q/wdE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755618154; c=relaxed/simple; bh=YzTF1QFMS76frYrgJNGJST/Qy2p5LYZttj4rMAqCyiE=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=bb4f/bONXotLjOZB1X7cAvz2Y3gNaWrTEqJgwHwmu+Z3HHvrFsu4Wtj5MgGTHHfOxGZhmrCcGL6aFsU5cr++elNmBLeb9yePSK77/3g419xBkOYSCFoCo0sP7DcvAoMn1Gt9EoLB09SGjc2jga+v46qt6nJJ9KSr9tzrcTWvsp0= 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=209.85.166.207 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-f207.google.com with SMTP id e9e14a558f8ab-3e6688959easo23406755ab.3 for ; Tue, 19 Aug 2025 08:42:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755618152; x=1756222952; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=TK/EKS4eetX6yWIzFURmsvpvay0L/jjfJICuasx8m/w=; b=iNiwXZQnIuckFrgm4T8ZI4zlVVEVSQDr0QYhJSrI0xD6Tg5IHmyUD+zt+Pp5/Q275t ih73O1RpUMb8j5d6Zi+SUI/6pi8qk6Uq49aA+KRHciYcxwuZIKFZ6pItkodJTaptq0oS P0Ns4TkKdQHsxSpeFkGSo9SWWMrcrAKof4MxK+NNowakK0Tvnr6zYXvN+5u24g1xe5ag TThlIKB1s6JAbBVu/+ifykOVMgasZos+w0wxtNoIkkjbZxWQmW5v1b2QkrGfJSbFkITw MF5+vW3JF1czwyARAfIGN0DDPx+SM8ynD5w/2AsQW71ig/MiOubnhF/6wghovV6oyiRs 4w/w== X-Forwarded-Encrypted: i=1; AJvYcCV4uKko1hiZ1TyG0hoIXCyZjDfKPxwxU69GUaUZ4bVNdOBry50Flfdr3Y7ku9VPCMbZHROoSejDwKJAHw==@vger.kernel.org X-Gm-Message-State: AOJu0Yx8/BLzx0MoYOD/yBPL7ku0Hg7LNK+GbjvgieBOa2A7Ydu9A1kz S3A19ATP6TCAeYWXW8FImZxVweSXMQXHCJ2BJR8ioI1MIslhQ6R03KFZHmJnMPumZ64uJIgmFXd KW6KYVMTCQsrhRmpRHtpccMrptoRC4ForkZF1EeHWV6svhAo/ir5DmT26zlc= X-Google-Smtp-Source: AGHT+IG+tROFW0E1dZyO6C+QKpjUNes+pj0QDAa/psex7DDHuBGxS4hRm8Ylrb+BrYUcIoIO8WOTSFjT6ruU99cVNGd+04dB9D/X Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1a63:b0:3e5:7dac:d696 with SMTP id e9e14a558f8ab-3e676668a28mr55937245ab.19.1755618152193; Tue, 19 Aug 2025 08:42:32 -0700 (PDT) Date: Tue, 19 Aug 2025 08:42:32 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68a49b68.050a0220.e29e5.00c9.GAE@google.com> Subject: [syzbot] [fbdev?] KASAN: slab-out-of-bounds Read in fb_pad_aligned_buffer (2) From: syzbot To: deller@gmx.de, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, simona@ffwll.ch, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 2674d1eadaa2 Add linux-next specific files for 20250812 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=10c12af0580000 kernel config: https://syzkaller.appspot.com/x/.config?x=712e4169f26d539a dashboard link: https://syzkaller.appspot.com/bug?extid=ef4f385c7132a39eabb2 compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/d6fec408ef67/disk-2674d1ea.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/27b3f312fa12/vmlinux-2674d1ea.xz kernel image: https://storage.googleapis.com/syzbot-assets/56e7b0c45a7e/bzImage-2674d1ea.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ef4f385c7132a39eabb2@syzkaller.appspotmail.com overlayfs: conflicting options: nfs_export=on,metacopy=on ================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:641 [inline] BUG: KASAN: slab-out-of-bounds in fb_pad_aligned_buffer+0x57e/0x5f0 drivers/video/fbdev/core/fbmem.c:96 Read of size 1 at addr ffff8880593d7a10 by task syz.6.4465/21843 CPU: 1 UID: 0 PID: 21843 Comm: syz.6.4465 Not tainted 6.17.0-rc1-next-20250812-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __fb_pad_aligned_buffer include/linux/fb.h:641 [inline] fb_pad_aligned_buffer+0x57e/0x5f0 drivers/video/fbdev/core/fbmem.c:96 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:98 [inline] bit_putcs+0x1648/0x1a50 drivers/video/fbdev/core/bitblit.c:184 fbcon_putcs+0x3e5/0x5f0 drivers/video/fbdev/core/fbcon.c:1327 do_update_region+0x21c/0x440 drivers/tty/vt/vt.c:617 update_region+0x1ce/0x490 drivers/tty/vt/vt.c:641 vcs_write+0xd65/0x1260 drivers/tty/vt/vc_screen.c:698 do_loop_readv_writev fs/read_write.c:850 [inline] vfs_writev+0x4b6/0x960 fs/read_write.c:1059 do_writev+0x14d/0x2d0 fs/read_write.c:1103 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f68db78ebe9 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:00007f68dc5ed038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f68db9b5fa0 RCX: 00007f68db78ebe9 RDX: 000000000000000e RSI: 0000200000000c40 RDI: 0000000000000004 RBP: 00007f68db811e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f68db9b6038 R14: 00007f68db9b5fa0 R15: 00007fff61c4c208 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880593d7a80 pfn:0x593d4 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f8(unknown) raw: 00fff00000000040 0000000000000000 dead000000000122 0000000000000000 raw: ffff8880593d7a80 0000000000000000 00000000f8000000 0000000000000000 head: 00fff00000000040 0000000000000000 dead000000000122 0000000000000000 head: ffff8880593d7a80 0000000000000000 00000000f8000000 0000000000000000 head: 00fff00000000002 ffffea000164f501 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x140cc0(GFP_USER|__GFP_COMP), pid 19098, tgid 19083 (syz.1.3690), ts 809460860721, free_ts 809191260089 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 ___kmalloc_large_node+0x5f/0x1b0 mm/slub.c:4306 __kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:4337 __do_kmalloc_node mm/slub.c:4353 [inline] __kmalloc_noprof+0x36f/0x4f0 mm/slub.c:4377 kmalloc_noprof include/linux/slab.h:909 [inline] fbcon_set_font+0x519/0xe90 drivers/video/fbdev/core/fbcon.c:2536 con_font_set drivers/tty/vt/vt.c:4887 [inline] con_font_op+0xcac/0x1070 drivers/tty/vt/vt.c:4934 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline] vt_ioctl+0x1a8a/0x1f00 drivers/tty/vt/vt_ioctl.c:751 tty_ioctl+0x926/0xde0 drivers/tty/tty_io.c:2792 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 19061 tgid 19060 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 discard_slab mm/slub.c:2753 [inline] __put_partials+0x156/0x1a0 mm/slub.c:3218 put_cpu_partial+0x17c/0x250 mm/slub.c:3293 __slab_free+0x2d5/0x3c0 mm/slub.c:4550 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] __do_kmalloc_node mm/slub.c:4364 [inline] __kmalloc_noprof+0x224/0x4f0 mm/slub.c:4377 kmalloc_noprof include/linux/slab.h:909 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x1e8/0x5a0 security/tomoyo/file.c:723 security_file_ioctl+0xcb/0x2d0 security/security.c:2982 __do_sys_ioctl fs/ioctl.c:592 [inline] __se_sys_ioctl+0x47/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880593d7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880593d7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880593d7a00: 00 00 fe fe fe fe fe fe fe fe fe fe fe fe fe fe ^ ffff8880593d7a80: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ffff8880593d7b00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ================================================================== --- This report is generated by a bot. 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