From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f72.google.com (mail-oo1-f72.google.com [209.85.161.72]) (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 97F413358BA for ; Wed, 18 Feb 2026 21:59:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771451974; cv=none; b=jdcXrV9PnRLCm+hi6Tx5/4GdHV4h3PK6OywFVr55Kg6+5yQblqf0XLbF76MCX4/KJnZ9ZQQ/QA0MT+83eBrSQXSV237C7oaVvl6vn7lRHTjFsciABqt4faFGwv5EKd59LzBjT+snT9p/wYC/nnG9J7mEz1kbc9qPAEDUHxyE/DY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771451974; c=relaxed/simple; bh=Tw4hcgmBK8DZNhE9fnYtm0u/wgUGVjXclYtM7aB/kPY=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=A3JHiijwK/OA8BQ52GkZtRuM0rrmZMqAOHgigKPmOh+q9b7SdlOE9EqkHw+xuMkaxcHR86nYxNIV5g5f+tiVY+QQg0fF1aY0KO0LvdRUIADlh12RphJlawuuYHJiXBHuHG4rEe6ZSlfp4EF8G0kkVvUjtw7H/IumPqH9u/YyJ08= 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=209.85.161.72 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-oo1-f72.google.com with SMTP id 006d021491bc7-67992287096so4277103eaf.2 for ; Wed, 18 Feb 2026 13:59:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771451971; x=1772056771; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=GW4Ocoxumxoq9rGVwk3byPUBA9fwWdC8c7Fz/FXOR4o=; b=WbjlSB4SZV+LWonAVj/ooeZUbFYTQNG5xmb+TaexPopmw0DsdvQAlUxgFi/5hiZLPA Jcjh7ySejg6xTy4UtNvqKrWmSe+JYKqGiu7J2egglxrfWNSNa7o2clPy01JeAVkPAIob 0AbBO2g+r4yCjDZlMbgQobeTwWP5/T3yA3M1cdqzyZQqxo1FjkX1ZSQA24bPOgD+ENq4 dr2BwaaTJC6NmtfdPyHCnDp0z/go7sieVz2Z/6ki1JHZRAffQ1wxxHHaZASXSkV2T2cx Xlnisoub45C/U6ObfZxYmqJZsMV2sgaEUEr/mlVTi6znYx10nGYDwlv0zJdau/15prw+ vAqQ== X-Forwarded-Encrypted: i=1; AJvYcCVXGJSHItbu8T1bn/R9ti/aTNeHNxtTLIOt2piTTHGeYDfs85VWr9hmtu9mt0USDpNg2lXbZn7PZZB7YV0=@vger.kernel.org X-Gm-Message-State: AOJu0Yz9tqxTADmFmHlZoQhrT1Gg5zupXZkdqtJIUtTk7pWjlOjQ8LxX 84moI9coa9nuBtAmFR2kaQkOLeAKS5Ucg2RgQ2sM2QOp7QMKxxPqalyZFTh+/s3GUIC4+cBsi36 spHy0EF2sE3KjUmK9M7NBBrBiuEorSBmiqUimkSeAypny7fiX+q9kBxQiKu8= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:1886:b0:677:cb1:37fd with SMTP id 006d021491bc7-6785bb676d8mr8341992eaf.58.1771451971502; Wed, 18 Feb 2026 13:59:31 -0800 (PST) Date: Wed, 18 Feb 2026 13:59:31 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69963643.a70a0220.2c38d7.0120.GAE@google.com> Subject: [syzbot] [mm?] kernel BUG in __page_table_check_zero (3) From: syzbot To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, pasha.tatashin@soleen.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 18be4ca5cb4e riscv: lib: optimize strlen loop efficiency git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next console output: https://syzkaller.appspot.com/x/log.txt?x=10c59b3a580000 kernel config: https://syzkaller.appspot.com/x/.config?x=781a4eb07921464d dashboard link: https://syzkaller.appspot.com/bug?extid=2b5fe617654be3d8848b compiler: riscv64-linux-gnu-gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 userspace arch: riscv64 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/a741b348759c/non_bootable_disk-18be4ca5.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/c6b87a8d77c4/vmlinux-18be4ca5.xz kernel image: https://storage.googleapis.com/syzbot-assets/d5126373321c/Image-18be4ca5.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+2b5fe617654be3d8848b@syzkaller.appspotmail.com ------------[ cut here ]------------ kernel BUG at [] mm/page_table_check.c:142! Kernel BUG [#1] Modules linked in: CPU: 0 UID: 0 PID: 3940 Comm: syz.1.16 Not tainted syzkaller #0 PREEMPT Hardware name: riscv-virtio,qemu (DT) epc : __page_table_check_zero+0x396/0x544 mm/page_table_check.c:142 ra : __page_table_check_zero+0x396/0x544 mm/page_table_check.c:142 epc : ffffffff80bfdcce ra : ffffffff80bfdcce sp : ffff8f800af273e0 gp : ffffffff89f9df20 tp : ffffaf8013f64f80 t0 : ffff8f800af27380 t1 : fffff5ef0269a409 t2 : 0000000000000000 s0 : ffff8f800af27450 s1 : ffffaf80134d2048 a0 : 0000000000000005 a1 : 0000000000000000 a2 : 0000000000000002 a3 : ffffffff80bfdcce a4 : 0000000000000000 a5 : ffffaf8013f65f80 a6 : 0000000000000003 a7 : ffffaf80134d204b s2 : 0000000000000001 s3 : 0000000000000000 s4 : ffffaf80134d2000 s5 : dfffffff00000000 s6 : 00000000000b2a00 s7 : 0000000000000200 s8 : 0000000000000009 s9 : 0000000000007fff s10: fffffffef1416bb0 s11: ffffffff8a0b5d80 t3 : 0000000000000001 t4 : fffff5ef0269a409 t5 : fffff5ef0269a40a t6 : 0000000000000002 ssp : 0000000000000000 status: 0000000200000120 badaddr: ffffffff80bfdcce cause: 0000000000000003 [] __page_table_check_zero+0x396/0x544 mm/page_table_check.c:142 [] page_table_check_free include/linux/page_table_check.h:43 [inline] [] free_pages_prepare mm/page_alloc.c:1434 [inline] [] free_unref_folios+0xa22/0x1dc8 mm/page_alloc.c:3030 [] folios_put_refs+0x41c/0x61c mm/swap.c:1002 [] free_pages_and_swap_cache+0x29c/0x480 mm/swap_state.c:358 [] __tlb_batch_free_encoded_pages+0xe4/0x25c mm/mmu_gather.c:137 [] tlb_batch_pages_flush mm/mmu_gather.c:150 [inline] [] tlb_flush_mmu_free mm/mmu_gather.c:398 [inline] [] tlb_flush_mmu mm/mmu_gather.c:405 [inline] [] tlb_finish_mmu+0x188/0x824 mm/mmu_gather.c:530 [] exit_mmap+0x396/0xca8 mm/mmap.c:1290 [] __mmput+0x106/0x3d0 kernel/fork.c:1173 [] mmput+0x74/0x88 kernel/fork.c:1196 [] exit_mm kernel/exit.c:581 [inline] [] do_exit+0x792/0x2828 kernel/exit.c:959 [] __do_sys_exit kernel/exit.c:1079 [inline] [] __se_sys_exit kernel/exit.c:1077 [inline] [] __riscv_sys_exit+0x48/0x54 kernel/exit.c:1077 [] syscall_handler+0x92/0x114 arch/riscv/include/asm/syscall.h:112 [] do_trap_ecall_u+0x3d2/0x58c arch/riscv/kernel/traps.c:344 [] handle_exception+0x15e/0x16a arch/riscv/kernel/entry.S:232 Code: 7f80 8526 c0ef ec3f 8a2a b791 6097 ff90 80e7 7e60 (9002) 6097 ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 7f80 flw fs0,56(a5) 2: 8526 mv a0,s1 4: ec3fc0ef jal 0xffffffffffffcec6 8: 8a2a mv s4,a0 a: b791 j 0xffffffffffffff4e c: ff906097 auipc ra,0xff906 10: 7e6080e7 jalr 2022(ra) # 0xff9067f2 * 14: 9002 ebreak <-- trapping instruction 16: 9760 .short 0x6097 --- 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