From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B147AC32792 for ; Thu, 3 Oct 2019 14:33:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 837C5215EA for ; Thu, 3 Oct 2019 14:33:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726508AbfJCOdQ (ORCPT ); Thu, 3 Oct 2019 10:33:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33594 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726393AbfJCOdQ (ORCPT ); Thu, 3 Oct 2019 10:33:16 -0400 Received: from mail-qt1-f198.google.com (mail-qt1-f198.google.com [209.85.160.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3FA747FDCA for ; Thu, 3 Oct 2019 14:33:15 +0000 (UTC) Received: by mail-qt1-f198.google.com with SMTP id h10so3045105qtq.11 for ; Thu, 03 Oct 2019 07:33:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=w1UQcOsVykX6Y03oTK99bBNgy905gW+1mY3fluD8DBg=; b=Uc2KjJIA3uf73NeqGaEZFIzDXigsWOzXTivkOUVuUM9xUhKxZCkQ7Jq5DSz+EsrQFN VfxZVqU/gw4+tzrQvQS6XeICZgjyRXT9wzM4KK2qKVhrjmnZa1qncAASzxmrhZg+kNHd 8XDMS8Y4wp+EquYHyKoV9TabgWCahMk4WoJM6222jGG/wiDQYkrxOZQLtindKmbL7M+E /My23ZvKH/wI9YutC3ieFBaG9AyX+BzSw/jyebcdEbvQU1jwoU9ep00BWO+reO+SGr5u /RGhejvgQkaJ4BurHzn06kDAi924aR8UDw1sQUaDxntxkxisnMtiuh+D0DME+e96jjdW xmbA== X-Gm-Message-State: APjAAAUG9WdiTQZxWJFjVGU9Ig44Cye9jQ9gkjL1F4ixpdmkKh4IpUWz 9MOmFnMKn96WTAWbLUHJRE/BMk+h1n4MWLOsFRKr4761nuBsyl6iV6XOjsikjK9zRSWgvCvGBh8 ieWVi+FI0CydsjR7yj7f/qwJtioPAMX7/syeDLA== X-Received: by 2002:ac8:2e31:: with SMTP id r46mr9990948qta.293.1570113194317; Thu, 03 Oct 2019 07:33:14 -0700 (PDT) X-Google-Smtp-Source: APXvYqx+Y8IQiiGc5AqZP3z+RjaLu6cmq4oynUuS0dfeCiP1gDoC8THzlbnbKrR8bi8vkWLmjHAoYnwukAUz3CS0vWU= X-Received: by 2002:ac8:2e31:: with SMTP id r46mr9990913qta.293.1570113194010; Thu, 03 Oct 2019 07:33:14 -0700 (PDT) MIME-Version: 1.0 References: <20191003051627.19835-1-lsahlber@redhat.com> In-Reply-To: From: David Wysochanski Date: Thu, 3 Oct 2019 10:32:37 -0400 Message-ID: Subject: Re: [PATCH] cifs: use cifsInodeInfo->open_file_lock while iterating to avoid a panic To: Steve French Cc: Ronnie Sahlberg , linux-cifs Content-Type: text/plain; charset="UTF-8" Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org I'm ok with stable On Thu, Oct 3, 2019 at 10:21 AM Steve French wrote: > > opinions on stable? The patch it refers to was cc:stable 487317c99477 > > On Thu, Oct 3, 2019 at 12:16 AM Ronnie Sahlberg wrote: > > > > From: Dave Wysochanski > > > > Commit 487317c99477 ("cifs: add spinlock for the openFileList to > > cifsInodeInfo") added cifsInodeInfo->open_file_lock spin_lock to protect > > the openFileList, but missed a few places where cifs_inode->openFileList > > was enumerated. Change these remaining tcon->open_file_lock to > > cifsInodeInfo->open_file_lock to avoid panic in is_size_safe_to_change. > > > > [17313.245641] RIP: 0010:is_size_safe_to_change+0x57/0xb0 [cifs] > > [17313.245645] Code: 68 40 48 89 ef e8 19 67 b7 f1 48 8b 43 40 48 8d 4b 40 48 8d 50 f0 48 39 c1 75 0f eb 47 48 8b 42 10 48 8d 50 f0 48 39 c1 74 3a <8b> 80 88 00 00 00 83 c0 01 a8 02 74 e6 48 89 ef c6 07 00 0f 1f 40 > > [17313.245649] RSP: 0018:ffff94ae1baefa30 EFLAGS: 00010202 > > [17313.245654] RAX: dead000000000100 RBX: ffff88dc72243300 RCX: ffff88dc72243340 > > [17313.245657] RDX: dead0000000000f0 RSI: 00000000098f7940 RDI: ffff88dd3102f040 > > [17313.245659] RBP: ffff88dd3102f040 R08: 0000000000000000 R09: ffff94ae1baefc40 > > [17313.245661] R10: ffffcdc8bb1c4e80 R11: ffffcdc8b50adb08 R12: 00000000098f7940 > > [17313.245663] R13: ffff88dc72243300 R14: ffff88dbc8f19600 R15: ffff88dc72243428 > > [17313.245667] FS: 00007fb145485700(0000) GS:ffff88dd3e000000(0000) knlGS:0000000000000000 > > [17313.245670] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [17313.245672] CR2: 0000026bb46c6000 CR3: 0000004edb110003 CR4: 00000000007606e0 > > [17313.245753] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > [17313.245756] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > [17313.245759] PKRU: 55555554 > > [17313.245761] Call Trace: > > [17313.245803] cifs_fattr_to_inode+0x16b/0x580 [cifs] > > [17313.245838] cifs_get_inode_info+0x35c/0xa60 [cifs] > > [17313.245852] ? kmem_cache_alloc_trace+0x151/0x1d0 > > [17313.245885] cifs_open+0x38f/0x990 [cifs] > > [17313.245921] ? cifs_revalidate_dentry_attr+0x3e/0x350 [cifs] > > [17313.245953] ? cifsFileInfo_get+0x30/0x30 [cifs] > > [17313.245960] ? do_dentry_open+0x132/0x330 > > [17313.245963] do_dentry_open+0x132/0x330 > > [17313.245969] path_openat+0x573/0x14d0 > > [17313.245974] do_filp_open+0x93/0x100 > > [17313.245979] ? __check_object_size+0xa3/0x181 > > [17313.245986] ? audit_alloc_name+0x7e/0xd0 > > [17313.245992] do_sys_open+0x184/0x220 > > [17313.245999] do_syscall_64+0x5b/0x1b0 > > > > Fixes: 487317c99477 ("cifs: add spinlock for the openFileList to cifsInodeInfo") > > > > Signed-off-by: Dave Wysochanski > > Reviewed-by: Ronnie Sahlberg > > --- > > fs/cifs/file.c | 27 +++++++++++---------------- > > 1 file changed, 11 insertions(+), 16 deletions(-) > > > > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > > index 4b95700c507c..3758237bf951 100644 > > --- a/fs/cifs/file.c > > +++ b/fs/cifs/file.c > > @@ -1840,13 +1840,12 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode, > > { > > struct cifsFileInfo *open_file = NULL; > > struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb); > > - struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); > > > > /* only filter by fsuid on multiuser mounts */ > > if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER)) > > fsuid_only = false; > > > > - spin_lock(&tcon->open_file_lock); > > + spin_lock(&cifs_inode->open_file_lock); > > /* we could simply get the first_list_entry since write-only entries > > are always at the end of the list but since the first entry might > > have a close pending, we go through the whole list */ > > @@ -1858,7 +1857,7 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode, > > /* found a good file */ > > /* lock it so it will not be closed on us */ > > cifsFileInfo_get(open_file); > > - spin_unlock(&tcon->open_file_lock); > > + spin_unlock(&cifs_inode->open_file_lock); > > return open_file; > > } /* else might as well continue, and look for > > another, or simply have the caller reopen it > > @@ -1866,7 +1865,7 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode, > > } else /* write only file */ > > break; /* write only files are last so must be done */ > > } > > - spin_unlock(&tcon->open_file_lock); > > + spin_unlock(&cifs_inode->open_file_lock); > > return NULL; > > } > > > > @@ -1877,7 +1876,6 @@ cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only, > > { > > struct cifsFileInfo *open_file, *inv_file = NULL; > > struct cifs_sb_info *cifs_sb; > > - struct cifs_tcon *tcon; > > bool any_available = false; > > int rc = -EBADF; > > unsigned int refind = 0; > > @@ -1897,16 +1895,15 @@ cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only, > > } > > > > cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb); > > - tcon = cifs_sb_master_tcon(cifs_sb); > > > > /* only filter by fsuid on multiuser mounts */ > > if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER)) > > fsuid_only = false; > > > > - spin_lock(&tcon->open_file_lock); > > + spin_lock(&cifs_inode->open_file_lock); > > refind_writable: > > if (refind > MAX_REOPEN_ATT) { > > - spin_unlock(&tcon->open_file_lock); > > + spin_unlock(&cifs_inode->open_file_lock); > > return rc; > > } > > list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { > > @@ -1918,7 +1915,7 @@ cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only, > > if (!open_file->invalidHandle) { > > /* found a good writable file */ > > cifsFileInfo_get(open_file); > > - spin_unlock(&tcon->open_file_lock); > > + spin_unlock(&cifs_inode->open_file_lock); > > *ret_file = open_file; > > return 0; > > } else { > > @@ -1938,7 +1935,7 @@ cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only, > > cifsFileInfo_get(inv_file); > > } > > > > - spin_unlock(&tcon->open_file_lock); > > + spin_unlock(&cifs_inode->open_file_lock); > > > > if (inv_file) { > > rc = cifs_reopen_file(inv_file, false); > > @@ -1953,7 +1950,7 @@ cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only, > > cifsFileInfo_put(inv_file); > > ++refind; > > inv_file = NULL; > > - spin_lock(&tcon->open_file_lock); > > + spin_lock(&cifs_inode->open_file_lock); > > goto refind_writable; > > } > > > > @@ -4461,17 +4458,15 @@ static int cifs_readpage(struct file *file, struct page *page) > > static int is_inode_writable(struct cifsInodeInfo *cifs_inode) > > { > > struct cifsFileInfo *open_file; > > - struct cifs_tcon *tcon = > > - cifs_sb_master_tcon(CIFS_SB(cifs_inode->vfs_inode.i_sb)); > > > > - spin_lock(&tcon->open_file_lock); > > + spin_lock(&cifs_inode->open_file_lock); > > list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { > > if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) { > > - spin_unlock(&tcon->open_file_lock); > > + spin_unlock(&cifs_inode->open_file_lock); > > return 1; > > } > > } > > - spin_unlock(&tcon->open_file_lock); > > + spin_unlock(&cifs_inode->open_file_lock); > > return 0; > > } > > > > -- > > 2.13.6 > > > > > -- > Thanks, > > Steve -- Dave Wysochanski Principal Software Maintenance Engineer T: 919-754-4024