From patchwork Thu Oct 3 05:16:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ronnie Sahlberg X-Patchwork-Id: 11172161 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1EA45139A for ; Thu, 3 Oct 2019 05:16:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EFD16222C2 for ; Thu, 3 Oct 2019 05:16:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726116AbfJCFQm (ORCPT ); Thu, 3 Oct 2019 01:16:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45244 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725497AbfJCFQm (ORCPT ); Thu, 3 Oct 2019 01:16:42 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5428430917AA; Thu, 3 Oct 2019 05:16:41 +0000 (UTC) Received: from test1135.test.redhat.com (vpn2-54-82.bne.redhat.com [10.64.54.82]) by smtp.corp.redhat.com (Postfix) with ESMTP id AA48C19C7F; Thu, 3 Oct 2019 05:16:40 +0000 (UTC) From: Ronnie Sahlberg To: linux-cifs Cc: Steve French , Dave Wysochanski Subject: [PATCH] cifs: use cifsInodeInfo->open_file_lock while iterating to avoid a panic Date: Thu, 3 Oct 2019 15:16:27 +1000 Message-Id: <20191003051627.19835-1-lsahlber@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Thu, 03 Oct 2019 05:16:41 +0000 (UTC) Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org 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; }