From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f172.google.com (mail-pg1-f172.google.com [209.85.215.172]) (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 CDF54B658 for ; Fri, 25 Oct 2024 04:40:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729831221; cv=none; b=SvdoqRoISOJnNc9cx3eDKe+LpIAlWu1qMkEL4U3Bv66gzw/9eXrdmfXWOJnhN/sMjHyPed6J35mk/RxKNYnI6DQT1mq6wM3+UoKVMPdwGPKSurt0yNjBPHpbNlP+IlZURmFcsia/3lyHcpWsa8ksYUcE0ELMlv46xSvgKyTjUu4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729831221; c=relaxed/simple; bh=ld6+ggNizA3A2eIeDt5kCacXAG+qxFT6pKHcEwM1EYg=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=dbOp89USb8eZqdXzy8FqR8HBENPhi3QtOmz3zoyQeocQcut0No0ihbSkcvkrT3qT+bPJswOcoGv/69tvURw8pNqOAe3tAc8ZhTSjRC8dO61JiBpOF45q4m6fLVTz8OY/CJGoSfjMGsvhYV9AAnXlhybn8s39pFETdlPHpXyBBqE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=N5KB27CW; arc=none smtp.client-ip=209.85.215.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="N5KB27CW" Received: by mail-pg1-f172.google.com with SMTP id 41be03b00d2f7-7edb6879196so828740a12.3 for ; Thu, 24 Oct 2024 21:40:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1729831219; x=1730436019; darn=lists.linux.dev; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=To20Nw2+64QsmpudbVv9vAcH+arowhkF0pMy9qpll/g=; b=N5KB27CWvOOo2q0W3dXNwoW6F3VgVMLtkfb1M4rosjB/b7zaUTDTeaB3EEZMd2Kuca RAsMPwQmJD8sq7eZHa6ZdkQLmLtKCNMh61EaWgU9ujVuy8kmrPFNmBTMBKlzOU5UPlcB Q56ZYcfwwXnUbZ9m7LwYryOMC0D5hbiYo28E61xo5djlSBls8nt33slzaIiHnEmOaSUE xrSzgi3ivjiMRoLC8JMrKzjgQvkeiCR5Wr+yiA3O5kWdLryUgUJGfmqPofosh1DqY5sU TQIwfkuHhScpNdu128eFoir6zHgfvocY98KeayqgWs0nUFIExsGFuq4QNj9oHs6P2DFr 1Siw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729831219; x=1730436019; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=To20Nw2+64QsmpudbVv9vAcH+arowhkF0pMy9qpll/g=; b=eWAxn5Ry+y13kWdUrZHJ8ikVYMYKv7wxgFkFY9hIuOvmSAFNA0dj6zrrTHPxbBTT/r h7Adda00U7HqYSDnY4f8gBWpPjlJ7v59efznDw9J3f0X1jIsZwzBGLkiw+pydaTdvsXJ m2fqGtLLgjjAjz0oEj/g9gMFUK4zqlQch3AvGmUiSjjGAvBS1A99phkXuXgMU4iPCoQb nHWNlTYhVEQHyTQa6s2W8addmFHrFLAKQCQGLF0Q/Uj4EazSuM2QmpN3gE13v+wvCTwE sQOxBV7aTc7wqPeqBaJuxxVOlk29Q0jeOPnnPjg29YO10eI3bFNhCkiYxKgi4FtFLmq5 quqQ== X-Forwarded-Encrypted: i=1; AJvYcCVY99NGwad1GdVH0q+6ClvwrCqADnQBM6CSESR6TT3PPaMletzN76UT1gJdCol2rtdZgxiwYg==@lists.linux.dev X-Gm-Message-State: AOJu0YwOotkFQ0E3/1u3oBtktaFrXKIL4jtw6XTrzehzroyDuNZErGbV hkzjAqZt+dQtiOvC1Q6Rl4U/l32NPWoOHT+rRf3Ut/MDDYCfwf0N X-Google-Smtp-Source: AGHT+IHBTV8w2SbFVAAq6pGuZ4l55H/pI1GXYvikxial0g6R3qFj6l0XrgeElRJ8DSCk0nRjWidKyA== X-Received: by 2002:a05:6a20:db0d:b0:1d7:c3e2:4e1f with SMTP id adf61e73a8af0-1d989b1ab76mr5069697637.25.1729831219094; Thu, 24 Oct 2024 21:40:19 -0700 (PDT) Received: from gmail.com ([24.130.68.0]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-72057921a78sm256782b3a.12.2024.10.24.21.40.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Oct 2024 21:40:18 -0700 (PDT) Date: Thu, 24 Oct 2024 21:40:16 -0700 From: Chang Yu To: dhowells@redhat.com Cc: jlayton@kernel.org, netfs@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+af5c06208fa71bf31b16@syzkaller.appspotmail.com, skhan@linuxfoundation.org Subject: [PATCH] netfs: Add a check for NULL folioq in netfs_writeback_unlock_folios Message-ID: Precedence: bulk X-Mailing-List: netfs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline syzkaller reported a null-pointer dereference bug (https://syzkaller.appspot.com/bug?extid=af5c06208fa71bf31b16) in netfs_writeback_unlock_folios caused by passing a NULL folioq to folioq_folio. Fix by adding a check before entering the loop. Signed-off-by: Chang Yu Reported-by: syzbot+af5c06208fa71bf31b16@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=af5c06208fa71bf31b16 Fixes: cd0277ed0c18 ("netfs: Use new folio_queue data type and iterator instead of xarray iter") --- fs/netfs/write_collect.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/netfs/write_collect.c b/fs/netfs/write_collect.c index 1d438be2e1b4..23d46a409ff2 100644 --- a/fs/netfs/write_collect.c +++ b/fs/netfs/write_collect.c @@ -98,7 +98,7 @@ static void netfs_writeback_unlock_folios(struct netfs_io_request *wreq, slot = 0; } - for (;;) { + while (folioq) { struct folio *folio; struct netfs_folio *finfo; unsigned long long fpos, fend; -- 2.47.0