Messages in this thread | | | Subject | Re: [Patch 6/6] Bind Mount Extensions 0.06 | From | Trond Myklebust <> | Date | Tue, 22 Feb 2005 09:58:45 -0500 |
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ty den 22.02.2005 Klokka 13:13 (+0100) skreiv Herbert Poetzl:
> diff -NurpP --minimal linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01/arch/sparc64/solaris/fs.c linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01-ro0.01/arch/sparc64/solaris/fs.c > --- linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01/arch/sparc64/solaris/fs.c 2004-12-25 01:54:50 +0100 > +++ linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01-ro0.01/arch/sparc64/solaris/fs.c 2005-02-19 06:32:05 +0100 > @@ -362,7 +362,7 @@ static int report_statvfs(struct vfsmoun > int j = strlen (p); > > if (j > 15) j = 15; > - if (IS_RDONLY(inode)) i = 1; > + if (IS_RDONLY(inode) || (mnt && MNT_IS_RDONLY(mnt))) i = 1;
Redundant check of mnt != NULL.
> if (mnt->mnt_flags & MNT_NOSUID) i |= 2; > if (!sysv_valid_dev(inode->i_sb->s_dev)) > return -EOVERFLOW; > @@ -398,7 +398,7 @@ static int report_statvfs64(struct vfsmo > int j = strlen (p); > > if (j > 15) j = 15; > - if (IS_RDONLY(inode)) i = 1; > + if (IS_RDONLY(inode) || (mnt && MNT_IS_RDONLY(mnt))) i = 1;
Redundant check of mnt != NULL
> if (mnt->mnt_flags & MNT_NOSUID) i |= 2; > if (!sysv_valid_dev(inode->i_sb->s_dev)) > return -EOVERFLOW; > diff -NurpP --minimal linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01/fs/namei.c linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01-ro0.01/fs/namei.c > --- linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01/fs/namei.c 2005-02-19 06:31:50 +0100 > +++ linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01-ro0.01/fs/namei.c 2005-02-19 06:32:05 +0100 > @@ -220,7 +220,7 @@ int permission(struct inode *inode, int > /* > * Nobody gets write access to a read-only fs. > */ > - if (IS_RDONLY(inode) && > + if ((IS_RDONLY(inode) || (nd && MNT_IS_RDONLY(nd->mnt))) && > (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) > return -EROFS;
This is very dodgy. What if the user is calling permission without setting the (currently optional) nameidata hint? Have you audited the kernel to find out if this is safe?
> diff -NurpP --minimal linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01/fs/open.c linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01-ro0.01/fs/open.c > --- linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01/fs/open.c 2005-02-19 06:31:43 +0100 > +++ linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01-ro0.01/fs/open.c 2005-02-19 06:32:05 +0100 > @@ -239,7 +239,7 @@ static inline long do_sys_truncate(const > goto dput_and_out; > > error = -EROFS; > - if (IS_RDONLY(inode)) > + if (IS_RDONLY(inode) || MNT_IS_RDONLY(nd.mnt)) > goto dput_and_out; > > error = -EPERM; > @@ -363,7 +363,7 @@ asmlinkage long sys_utime(char __user * > inode = nd.dentry->d_inode; > > error = -EROFS; > - if (IS_RDONLY(inode)) > + if (IS_RDONLY(inode) || MNT_IS_RDONLY(nd.mnt)) > goto dput_and_out; > > /* Don't worry, the checks are done in inode_change_ok() */ > @@ -420,7 +420,7 @@ long do_utimes(char __user * filename, s > inode = nd.dentry->d_inode; > > error = -EROFS; > - if (IS_RDONLY(inode)) > + if (IS_RDONLY(inode) || MNT_IS_RDONLY(nd.mnt)) > goto dput_and_out; > > /* Don't worry, the checks are done in inode_change_ok() */ > @@ -502,7 +502,8 @@ asmlinkage long sys_access(const char __ > if (!res) { > res = permission(nd.dentry->d_inode, mode, &nd); > /* SuS v2 requires we report a read only fs too */ > - if(!res && (mode & S_IWOTH) && IS_RDONLY(nd.dentry->d_inode) > + if(!res && (mode & S_IWOTH) > + && (IS_RDONLY(nd.dentry->d_inode) || MNT_IS_RDONLY(nd.mnt)) > && !special_file(nd.dentry->d_inode->i_mode)) > res = -EROFS; > path_release(&nd); > @@ -608,7 +609,7 @@ asmlinkage long sys_fchmod(unsigned int > inode = dentry->d_inode; > > err = -EROFS; > - if (IS_RDONLY(inode)) > + if (IS_RDONLY(inode) || (file && MNT_IS_RDONLY(file->f_vfsmnt))) > goto out_putf;
Redundant check of file != NULL.
> err = -EPERM; > if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) > @@ -640,7 +641,7 @@ asmlinkage long sys_chmod(const char __u > inode = nd.dentry->d_inode; > > error = -EROFS; > - if (IS_RDONLY(inode)) > + if (IS_RDONLY(inode) || MNT_IS_RDONLY(nd.mnt)) > goto dput_and_out; > > error = -EPERM; > diff -NurpP --minimal linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01/fs/reiserfs/ioctl.c linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01-ro0.01/fs/reiserfs/ioctl.c > --- linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01/fs/reiserfs/ioctl.c 2005-02-13 17:16:59 +0100 > +++ linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01-ro0.01/fs/reiserfs/ioctl.c 2005-02-19 06:32:05 +0100 > @@ -40,7 +40,8 @@ int reiserfs_ioctl (struct inode * inode > i_attrs_to_sd_attrs( inode, ( __u16 * ) &flags ); > return put_user(flags, (int __user *) arg); > case REISERFS_IOC_SETFLAGS: { > - if (IS_RDONLY(inode)) > + if (IS_RDONLY(inode) || > + (filp && MNT_IS_RDONLY(filp->f_vfsmnt))) > return -EROFS;
Redundant check for filp != NULL
> if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) > @@ -72,7 +73,8 @@ int reiserfs_ioctl (struct inode * inode > case REISERFS_IOC_SETVERSION: > if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) > return -EPERM; > - if (IS_RDONLY(inode)) > + if (IS_RDONLY(inode) || > + (filp && MNT_IS_RDONLY(filp->f_vfsmnt))) > return -EROFS;
Redundant check for filp != NULL
> if (get_user(inode->i_generation, (int __user *) arg)) > return -EFAULT; > diff -NurpP --minimal linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01/fs/reiserfs/xattr.c linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01-ro0.01/fs/reiserfs/xattr.c > --- linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01/fs/reiserfs/xattr.c 2005-02-13 17:16:59 +0100 > +++ linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01-xa0.01-ro0.01/fs/reiserfs/xattr.c 2005-02-19 06:32:05 +0100 > @@ -1355,7 +1355,7 @@ __reiserfs_permission (struct inode *ino > /* > * Nobody gets write access to a read-only fs. > */ > - if (IS_RDONLY(inode) && > + if ((IS_RDONLY(inode) || (nd && MNT_IS_RDONLY(nd->mnt))) && > (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) > return -EROFS;
See comment above for fs/namei.c:permission().
Cheers, Trond -- Trond Myklebust <trond.myklebust@fys.uio.no>
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