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 2CFA8345725 for ; Fri, 17 Oct 2025 13:13:34 +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=1760706817; cv=none; b=Gj36rDN5mOQIxS0MKu6dYVfFRNf0EjLvPiDuNlG+tLKsOT5j+9R06qNAOdaNP9fD7GVMbBbjkKE5UlWKrf3yV5mXO+Pv0/pmuxo1unh4YEyENNaDJzpGnwQsYHuR7TA84/0pTq4dGt2MNIhSr42vG0nOlFEo3OXzVvFzQK24zuo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760706817; c=relaxed/simple; bh=EfGGseb4tK/aZo/BQIEXgtsaRuh1loxFj7mF9jYFufo=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=X6BnqgOoJk1YOJ7NkvYBAeCmPp0KsQhlz3bIKLW1pVKXEOqJ4FWg5Bf5q1EjJKUm+8v2uucAGM0Gmo7c55P4bVgVpKF7QeGAE/D3LOJqwk/+2k9XQH0ooCi8HxiGmbgCM53s0usu02HK3AXCAgAnRExsA2VyhGrXbQfz9iWFADM= 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-427811cad57so56569935ab.1 for ; Fri, 17 Oct 2025 06:13:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760706814; x=1761311614; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=XaW0KohH6m9nMtE6syaVpsUAGQ5vS481dJIVMfKZMA4=; b=WagOg9ZQtCcik13f2oPdgM5oHgyOg9fyhfsGcCKWlHpINDzD0OjhM6Y7HsaBvb898E V4kYsEeM4De71fOAvtDnKQmc3cXRtDIOAG7T6rFDm1SCLNuSF66CfHeF6J3bfiUCe/Uh 2wGhAdr2sAkvQbpy/4Jd9yYvVdQqnoGQQQMMxSKup3VmFOI3A03vssZVcYT8/20x3Ae8 99/jOihUymSfm4rsXTMzAb/ZEf4/j5xSRfNuLZs1ZVd+Bkpkig5xL1IaDg66RRF97NGE 0gKl3WOwMK8zBcKnJ0b+hPXbpMDyGT5RqecGe3ZJJESxwFqz+BawPJjVtL+ovtVN6dM8 YpIw== X-Forwarded-Encrypted: i=1; AJvYcCUcGu5kST1mSV30SI+Z/EL2NfAvocPmrlbfksfYrakICQ1Mh4W0elXZ7ucOE414dDtaQAupTUt0bGidreE=@vger.kernel.org X-Gm-Message-State: AOJu0YyNne2cqLY2IXIJbXgHcjQgOk4butPHceLJFYkWWJLPhNYovDHW PxLUAcGQ21ssrS296N3CxAk19hxdZkA5MoxzcQeYH9dT/QMXZ7TbTW0SLCNdxMi38C2SzMR4qH3 dL4UPgUDp5ZayF1QqWt+fjATbjjjqgQ8EGF8OP/2CBItzQiBTQr68GKVgbt4= X-Google-Smtp-Source: AGHT+IFT533WooJwUxxXKh7D/GVz4Sl1wIZHPtn8xZNaKgrwgBTKJGVpXoKYZrCdpxyR8UDu8uMMQTCiUtCjEGduvg9tywe9Sz/d Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:3e06:b0:42f:9501:69e with SMTP id e9e14a558f8ab-430c5295023mr40647905ab.20.1760706814179; Fri, 17 Oct 2025 06:13:34 -0700 (PDT) Date: Fri, 17 Oct 2025 06:13:34 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68f240fe.050a0220.91a22.0420.GAE@google.com> Subject: [syzbot] [kernel?] KASAN: unknown-crash Read in copy_mc_to_kernel From: syzbot To: bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, x86@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 3a8660878839 Linux 6.18-rc1 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10109542580000 kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7 dashboard link: https://syzkaller.appspot.com/bug?extid=d155b4893773c196cdd9 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/b39e59492185/disk-3a866087.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a9f71abd3189/vmlinux-3a866087.xz kernel image: https://storage.googleapis.com/syzbot-assets/a8ee0fb986c2/bzImage-3a866087.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d155b4893773c196cdd9@syzkaller.appspotmail.com ================================================================== BUG: KASAN: unknown-crash in instrument_memcpy_before include/linux/instrumented.h:163 [inline] BUG: KASAN: unknown-crash in copy_mc_to_kernel+0x35/0xb0 arch/x86/lib/copy_mc.c:74 Read of size 4096 at addr ffff8880af860000 by task syz.5.1091/9436 CPU: 1 UID: 0 PID: 9436 Comm: syz.5.1091 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200 instrument_memcpy_before include/linux/instrumented.h:163 [inline] copy_mc_to_kernel+0x35/0xb0 arch/x86/lib/copy_mc.c:74 dump_page_copy fs/coredump.c:1321 [inline] dump_user_range+0x2e4/0xc90 fs/coredump.c:1372 elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111 coredump_write+0x116c/0x1900 fs/coredump.c:1049 vfs_coredump+0x1db5/0x2a60 fs/coredump.c:1170 get_signal+0x1108/0x1340 kernel/signal.c:3019 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:40 [inline] exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] irqentry_exit_to_user_mode+0x7e/0x110 kernel/entry/common.c:73 exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f97dd38eed1 Code: 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 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:00000000fffffd10 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f97dd5e6090 RCX: 00007f97dd38eec9 RDX: 0000000000000000 RSI: 00000000fffffd10 RDI: 0000000001000000 RBP: 00007f97dd411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f97dd5e6128 R14: 00007f97dd5e6090 R15: 00007ffcef26f528 The buggy address belongs to the physical page: page: refcount:3 mapcount:1 mapping:ffff888064726de8 index:0x14f pfn:0xaf860 memcg:ffff88801aea1a00 aops:ext4_da_aops ino:7f0 dentry name(?):"syz.IuCCpi" flags: 0xfff6800000002c(referenced|uptodate|lru|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff6800000002c ffffea0002c0b3c8 ffffea0002be1848 ffff888064726de8 raw: 000000000000014f 0000000000000000 0000000300000000 ffff88801aea1a00 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Movable, gfp_mask 0x152c4a(GFP_NOFS|__GFP_HIGHMEM|__GFP_MOVABLE|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 7122, tgid 7122 (syz.3.435), ts 155471149983, free_ts 153032620682 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2507 folio_alloc_noprof+0x1e/0x30 mm/mempolicy.c:2517 filemap_alloc_folio_noprof+0xdf/0x470 mm/filemap.c:1020 ractl_alloc_folio mm/readahead.c:189 [inline] page_cache_ra_unbounded+0x35d/0x9a0 mm/readahead.c:275 do_async_mmap_readahead mm/filemap.c:3376 [inline] filemap_fault+0x62d/0x12b0 mm/filemap.c:3475 __do_fault+0x138/0x390 mm/memory.c:5280 do_read_fault mm/memory.c:5698 [inline] do_fault mm/memory.c:5832 [inline] do_pte_missing mm/memory.c:4361 [inline] handle_pte_fault mm/memory.c:6177 [inline] __handle_mm_fault+0x35e3/0x5400 mm/memory.c:6318 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x165c/0x2a00 mm/gup.c:1428 __get_user_pages_locked mm/gup.c:1692 [inline] get_dump_page+0x1ac/0x3f0 mm/gup.c:2192 dump_user_range+0x1de/0xc90 fs/coredump.c:1366 elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111 page last free pid 7072 tgid 7068 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2963 folios_put_refs+0x584/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1120 shmem_truncate_range mm/shmem.c:1232 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360 evict+0x504/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880af85ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880af85ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8880af860000: 00 c9 2b 58 80 88 ff ff 00 00 00 00 00 00 00 00 ^ ffff8880af860080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880af860100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== --- 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