lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <20070928181330.27B367AC@kernel>
Date:	Fri, 28 Sep 2007 11:13:30 -0700
From:	Dave Hansen <haveblue@...ibm.com>
To:	linux-kernel@...r.kernel.org
Cc:	hch@...radead.org, miklos@...redi.hu,
	Dave Hansen <haveblue@...ibm.com>
Subject: [RFC][PATCH 1/8] get mount write in __dentry_open()


The first three patches here fix actual bugs.  I think
the last two will reduce the chance for any future bugs
to creep in.  RFC for now.

--

This is a bug fix for the r/o bind mount patch set.

We need to ensure taking a mnt write on the mnt
referenced by any new struct file.  

Signed-off-by: Dave Hansen <haveblue@...ibm.com>
---

 lxc-dave/fs/open.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff -puN fs/open.c~get-write-in-__dentry_open fs/open.c
--- lxc/fs/open.c~get-write-in-__dentry_open	2007-09-28 11:03:18.000000000 -0700
+++ lxc-dave/fs/open.c	2007-09-28 11:03:18.000000000 -0700
@@ -778,9 +778,15 @@ static struct file *__dentry_open(struct
 				FMODE_PREAD | FMODE_PWRITE;
 	inode = dentry->d_inode;
 	if (f->f_mode & FMODE_WRITE) {
-		error = get_write_access(inode);
+		error = mnt_want_write(mnt);
 		if (error)
 			goto cleanup_file;
+
+		error = get_write_access(inode);
+		if (error) {
+			mnt_drop_write(mnt);
+			goto cleanup_file;
+		}
 	}
 
 	f->f_mapping = inode->i_mapping;
@@ -820,8 +826,10 @@ static struct file *__dentry_open(struct
 
 cleanup_all:
 	fops_put(f->f_op);
-	if (f->f_mode & FMODE_WRITE)
+	if (f->f_mode & FMODE_WRITE) {
 		put_write_access(inode);
+		mnt_drop_write(mnt);
+	}
 	file_kill(f);
 	f->f_path.dentry = NULL;
 	f->f_path.mnt = NULL;
_
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ