From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: [RFC][PATCH 07/20] elevate mount count for extended attributes Date: Fri, 16 Jun 2006 16:12:18 -0700 Message-ID: <20060616231218.E2A4D665@localhost.localdomain> References: <20060616231213.D4C5D6AF@localhost.localdomain> Cc: linux-fsdevel@vger.kernel.org, herbert@13thfloor.at, viro@ftp.linux.org.uk, Dave Hansen Return-path: Received: from e5.ny.us.ibm.com ([32.97.182.145]:57531 "EHLO e5.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1751567AbWFPXMX (ORCPT ); Fri, 16 Jun 2006 19:12:23 -0400 To: linux-kernel@vger.kernel.org In-Reply-To: <20060616231213.D4C5D6AF@localhost.localdomain> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org This basically audits the callers of xattr_permission(), which calls permission() and can perform writes to the filesystem. Signed-off-by: Dave Hansen --- lxc-dave/fs/nfsd/nfs4proc.c | 7 ++++++- lxc-dave/fs/xattr.c | 14 ++++++++++++++ 2 files changed, 20 insertions(+), 1 deletion(-) diff -puN fs/nfsd/nfs4proc.c~C-xattr fs/nfsd/nfs4proc.c --- lxc/fs/nfsd/nfs4proc.c~C-xattr 2006-06-16 15:58:03.000000000 -0700 +++ lxc-dave/fs/nfsd/nfs4proc.c 2006-06-16 15:58:03.000000000 -0700 @@ -604,13 +604,18 @@ nfsd4_setattr(struct svc_rqst *rqstp, st return status; } } + status = mnt_want_write(current_fh->fh_export->ex_mnt); + if (status) + return status; status = nfs_ok; if (setattr->sa_acl != NULL) status = nfsd4_set_nfs4_acl(rqstp, current_fh, setattr->sa_acl); if (status) - return status; + goto out; status = nfsd_setattr(rqstp, current_fh, &setattr->sa_iattr, 0, (time_t)0); +out: + mnt_drop_write(current_fh->fh_export->ex_mnt); return status; } diff -puN fs/xattr.c~C-xattr fs/xattr.c --- lxc/fs/xattr.c~C-xattr 2006-06-16 15:58:03.000000000 -0700 +++ lxc-dave/fs/xattr.c 2006-06-16 15:58:03.000000000 -0700 @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -210,7 +211,11 @@ sys_setxattr(char __user *path, char __u error = user_path_walk(path, &nd); if (error) return error; + error = mnt_want_write(nd.mnt); + if (error) + return error; error = setxattr(nd.dentry, name, value, size, flags); + mnt_drop_write(nd.mnt); path_release(&nd); return error; } @@ -225,7 +230,11 @@ sys_lsetxattr(char __user *path, char __ error = user_path_walk_link(path, &nd); if (error) return error; + error = mnt_want_write(nd.mnt); + if (error) + return error; error = setxattr(nd.dentry, name, value, size, flags); + mnt_drop_write(nd.mnt); path_release(&nd); return error; } @@ -241,9 +250,14 @@ sys_fsetxattr(int fd, char __user *name, f = fget(fd); if (!f) return error; + error = mnt_want_write(f->f_vfsmnt); + if (error) + goto out_fput; dentry = f->f_dentry; audit_inode(NULL, dentry->d_inode, 0); error = setxattr(dentry, name, value, size, flags); + mnt_drop_write(f->f_vfsmnt); +out_fput: fput(f); return error; } _