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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 46BAFC432C0 for ; Wed, 20 Nov 2019 15:42:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B1F220714 for ; Wed, 20 Nov 2019 15:42:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732168AbfKTPmE (ORCPT ); Wed, 20 Nov 2019 10:42:04 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52966 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731810AbfKTPkU (ORCPT ); Wed, 20 Nov 2019 10:40:20 -0500 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iXS5X-0004cy-Fe; Wed, 20 Nov 2019 15:40:15 +0000 Received: from ben by deadeye with local (Exim 4.93-RC1) (envelope-from ) id 1iXS5V-0004Ny-Gm; Wed, 20 Nov 2019 15:40:13 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Dave Wysochanski" , "Ronnie Sahlberg" , "Pavel Shilovskiy" , "Steve French" Date: Wed, 20 Nov 2019 15:38:28 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 78/83] cifs: use cifsInodeInfo->open_file_lock while iterating to avoid a panic In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.78-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dave Wysochanski commit cb248819d209d113e45fed459773991518e8e80b upstream. 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 Signed-off-by: Steve French [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings Cc: Pavel Shilovskiy --- fs/cifs/file.c | 27 +++++++++++---------------- 1 file changed, 11 insertions(+), 16 deletions(-) --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -1756,13 +1756,12 @@ struct cifsFileInfo *find_readable_file( { 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 */ @@ -1774,7 +1773,7 @@ struct cifsFileInfo *find_readable_file( /* 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 @@ -1782,7 +1781,7 @@ struct cifsFileInfo *find_readable_file( } 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; } @@ -1791,7 +1790,6 @@ struct cifsFileInfo *find_writable_file( { struct cifsFileInfo *open_file, *inv_file = NULL; struct cifs_sb_info *cifs_sb; - struct cifs_tcon *tcon; bool any_available = false; int rc; unsigned int refind = 0; @@ -1807,16 +1805,15 @@ struct cifsFileInfo *find_writable_file( } 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 NULL; } list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { @@ -1828,7 +1825,7 @@ refind_writable: 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); return open_file; } else { if (!inv_file) @@ -1847,7 +1844,7 @@ refind_writable: 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); @@ -1861,7 +1858,7 @@ refind_writable: cifsFileInfo_put(inv_file); ++refind; inv_file = NULL; - spin_lock(&tcon->open_file_lock); + spin_lock(&cifs_inode->open_file_lock); goto refind_writable; } } @@ -3508,17 +3505,15 @@ static int cifs_readpage(struct file *fi 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; }