From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f208.google.com (mail-il1-f208.google.com [209.85.166.208]) (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 504013081AB for ; Mon, 22 Sep 2025 12:50:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.208 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758545436; cv=none; b=ZZRWU1LpMzx76Kq1PwK38887A/ZOCVR0K4Nl3jfQercC+Xw8Xu/6Jir+gnDO/qHlC2kS2K2iCJMjiRyXDXTiC+Up9ZMtnJo3X+fyeV0w6GAaBjz4o0+0W4YKBRRtGOCWrg2Wm/8cXitbc5CkR7z8BRqN4h9RejBOTiZO7PvElP8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758545436; c=relaxed/simple; bh=N7iBCeB1NX/WELU1UW6cPg88YTxzDsWTyL9DUs/4ZKE=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=urUws+aVShFY7QgvdT5fWKzbYmZE4NpWI/OmsMEh+GA/1d6k3DjsmmiOdgHO8159cVG9cZjthahaC7WKUrBPYBfuZMM+2bReIyNjRbqTeE320Fj7pSlTYRlwAH8lWqrJhcCIYAC3iVdLV4TyRvgCTIM3nY9CjAYTmJlsRuPJeKg= 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=209.85.166.208 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-f208.google.com with SMTP id e9e14a558f8ab-42574804553so35604715ab.0 for ; Mon, 22 Sep 2025 05:50:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758545433; x=1759150233; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=7FJVEO2JSEInNaIAVfqXuJ582DXJMN71NIxbYU3RqcA=; b=Jvw1yujss7e4S1DYYY6Ky/ZKcXZvmzTTLfSllIqMPwoO1yRcMagse7KCAvRH0v5j74 02MBBzX3m9Een8ZHmFXF+C66lKBTjUp8aSU5jt0JbQUTwlZtWHFWRT87/yNTGbYFm//a Y18wQfsZ01crRBXXZQsswghVwBUHUQWmuJTePddPKeDJ7pXeCUBMHlf3Ev1XtVuW0Aza OsznSGRQsFM2VDvEBSOvb4wcIZzttNGyirVdSyvNhrnIkv/wD4V0Oodhdcev3LdnW5D6 ctViLw3ysAS9n1L3YQHRla6oLlAjRYg+Xko5glanLawHCSiPYXUTdL7GBaCYLRxEJCV8 y5LA== X-Forwarded-Encrypted: i=1; AJvYcCV/l3Vezi9gw1E2VTdLWZ+Z5ye7BUjtiCsdaegv+dkhzZpYKRv+H5whbnXa88H7XX4NYi0wvOjjLl2l4g==@vger.kernel.org X-Gm-Message-State: AOJu0YyBfjinwok+vaWJGNOkXCkeYPldF6wRlm+Sb5vqfklKE/S+HBv5 LV70YpY/fP0V5XnOCmcKXDO2YSWQy6qVWUj0BzvisCoVqJ8ih6RXoibj71DQLDSh5baZReSu2d2 xLjjlQPwzusWplEuxVmegvIRKGAl65ama19laDhCbeunBn+6wQT2q54L0NGU= X-Google-Smtp-Source: AGHT+IHYpBtAyVXLokHcOTao6pfLrHb+XMXkLtI9C6fT1fK39oMs+hOhy4hVdkZNjyscp1qCAvz8YoVixCrJdLEG3gOum3gFSBE4 Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1489:b0:421:7d1:7af8 with SMTP id e9e14a558f8ab-424819a21a9mr188902185ab.26.1758545433518; Mon, 22 Sep 2025 05:50:33 -0700 (PDT) Date: Mon, 22 Sep 2025 05:50:33 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68d14619.a00a0220.37dadf.0049.GAE@google.com> Subject: [syzbot] [fbdev?] KASAN: slab-out-of-bounds Read in soft_cursor (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: f83ec76bf285 Linux 6.17-rc6 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17147b12580000 kernel config: https://syzkaller.appspot.com/x/.config?x=8f01d8629880e620 dashboard link: https://syzkaller.appspot.com/bug?extid=ae44b38396335bd847cd 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 (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-f83ec76b.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/bdedf70f8797/vmlinux-f83ec76b.xz kernel image: https://storage.googleapis.com/syzbot-assets/5bf9318d9242/bzImage-f83ec76b.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ae44b38396335bd847cd@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-out-of-bounds in soft_cursor+0x458/0xa10 drivers/video/fbdev/core/softcursor.c:70 Read of size 3 at addr ffff888054a70d7d by task kworker/2:2/3582 CPU: 2 UID: 0 PID: 3582 Comm: kworker/2:2 Not tainted syzkaller #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 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 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:189 __asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105 soft_cursor+0x458/0xa10 drivers/video/fbdev/core/softcursor.c:70 bit_cursor+0xe8c/0x17e0 drivers/video/fbdev/core/bitblit.c:370 fb_flashcursor drivers/video/fbdev/core/fbcon.c:408 [inline] fb_flashcursor+0x30d/0x400 drivers/video/fbdev/core/fbcon.c:377 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 10710: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4376 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] fbcon_set_font+0x434/0xb80 drivers/video/fbdev/core/fbcon.c:2536 con_font_set drivers/tty/vt/vt.c:4887 [inline] con_font_op+0x7fb/0xf50 drivers/tty/vt/vt.c:4934 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline] vt_ioctl+0x48f/0x30a0 drivers/tty/vt/vt_ioctl.c:751 tty_ioctl+0x661/0x1680 drivers/tty/tty_io.c:2792 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888054a70800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 621 bytes to the right of allocated 784-byte region [ffff888054a70800, ffff888054a70b10) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x54a70 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b842dc0 ffffea0000d94e00 dead000000000002 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842dc0 ffffea0000d94e00 dead000000000002 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001529c01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 12, tgid 12 (kworker/u32:0), ts 114834271157, free_ts 113350555070 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab mm/slub.c:2660 [inline] new_slab+0x247/0x330 mm/slub.c:2714 ___slab_alloc+0xcf2/0x1750 mm/slub.c:3901 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992 __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] __do_kmalloc_node mm/slub.c:4375 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] neigh_alloc net/core/neighbour.c:522 [inline] ___neigh_create+0x14e6/0x28c0 net/core/neighbour.c:656 ip6_finish_output2+0x1299/0x2020 net/ipv6/ip6_output.c:132 __ip6_finish_output+0x3cd/0x1010 net/ipv6/ip6_output.c:215 ip6_finish_output net/ipv6/ip6_output.c:226 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x1ca/0x3e0 net/ipv6/ip6_output.c:248 dst_output include/net/dst.h:461 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] ndisc_send_skb+0xa66/0x1e30 net/ipv6/ndisc.c:512 ndisc_send_rs+0x129/0x670 net/ipv6/ndisc.c:722 addrconf_dad_completed+0x49d/0x10d0 net/ipv6/addrconf.c:4360 addrconf_dad_work+0x855/0x14e0 net/ipv6/addrconf.c:4268 page last free pid 60 tgid 60 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:396 kmalloc_noprof include/linux/slab.h:905 [inline] netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:664 [inline] netdevice_event+0x365/0x9d0 drivers/infiniband/core/roce_gid_mgmt.c:823 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] unregister_netdevice_many_notify+0xf76/0x24c0 net/core/dev.c:12166 unregister_netdevice_many net/core/dev.c:12229 [inline] default_device_exit_batch+0x853/0xaf0 net/core/dev.c:12733 ops_exit_list net/core/net_namespace.c:204 [inline] ops_undo_list+0x360/0xab0 net/core/net_namespace.c:251 cleanup_net+0x408/0x890 net/core/net_namespace.c:682 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888054a70c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888054a70c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888054a70d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888054a70d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888054a70e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== --- This report is generated by a bot. 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