Re: [patch 01/15] security: pass path to inode_create

Tetsuo Handa
2008-06-04T05:34:44Z

Stephen Smalley wrote:
> This may be moot given the vfs maintainers' objections, but if you were
> to make this change, then logically you'd push the struct path all the
> way down and set it in the avc_audit_data so that it could be used by
> avc_audit() for emitting a pathname in the audit record. Likewise for
> the other hook changes.

Yes. That's one of improvements made possible by Miklos's patches.

----------
Subject: SELINUX: Set vfsmount field for audit logs.

By applying Miklos's patches which pass "struct vfsmount" to LSM
(posted at http://lkml.org/lkml/2008/5/29/207 ),
SELinux's audit logs can generate absolute pathnames for more operations.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
security/selinux/hooks.c | 35 ++++++++++++++++++++++-------------
1 file changed, 22 insertions(+), 13 deletions(-)

--- vfs.orig/security/selinux/hooks.c
+++ vfs/security/selinux/hooks.c
@@ -1427,10 +1427,11 @@ static int file_has_perm(struct task_str
}

/* Check whether a task can create a file. */
-static int may_create(struct inode *dir,
+static int may_create(struct path *dir_path,
struct dentry *dentry,
u16 tclass)
{
+ struct inode *dir = dir_path->dentry->d_inode;
struct task_security_struct *tsec;
struct inode_security_struct *dsec;
struct superblock_security_struct *sbsec;
@@ -1443,6 +1444,7 @@ static int may_create(struct inode *dir,
sbsec = dir->i_sb->s_security;

AVC_AUDIT_DATA_INIT(&ad, FS);
+ ad.u.fs.path.mnt = dir_path->mnt;
ad.u.fs.path.dentry = dentry;

rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
@@ -1485,11 +1487,12 @@ static int may_create_key(u32 ksid,
#define MAY_RMDIR 2

/* Check whether a task can link, unlink, or rmdir a file/directory. */
-static int may_link(struct inode *dir,
+static int may_link(struct path *dir_path,
struct dentry *dentry,
int kind)

{
+ struct inode *dir = dir_path->dentry->d_inode;
struct task_security_struct *tsec;
struct inode_security_struct *dsec, *isec;
struct avc_audit_data ad;
@@ -1501,6 +1504,7 @@ static int may_link(struct inode *dir,
isec = dentry->d_inode->i_security;

AVC_AUDIT_DATA_INIT(&ad, FS);
+ ad.u.fs.path.mnt = dir_path->mnt;
ad.u.fs.path.dentry = dentry;

av = DIR__SEARCH;
@@ -1529,11 +1533,13 @@ static int may_link(struct inode *dir,
return rc;
}

-static inline int may_rename(struct inode *old_dir,
+static inline int may_rename(struct path *old_dir_path,
struct dentry *old_dentry,
- struct inode *new_dir,
+ struct path *new_dir_path,
struct dentry *new_dentry)
{
+ struct inode *old_dir = old_dir_path->dentry->d_inode;
+ struct inode *new_dir = new_dir_path->dentry->d_inode;
struct task_security_struct *tsec;
struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
struct avc_audit_data ad;
@@ -1549,6 +1555,7 @@ static inline int may_rename(struct inod

AVC_AUDIT_DATA_INIT(&ad, FS);

+ ad.u.fs.path.mnt = old_dir_path->mnt;
ad.u.fs.path.dentry = old_dentry;
rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
DIR__REMOVE_NAME | DIR__SEARCH, &ad);
@@ -1565,6 +1572,7 @@ static inline int may_rename(struct inod
return rc;
}

+ ad.u.fs.path.mnt = new_dir_path->mnt;
ad.u.fs.path.dentry = new_dentry;
av = DIR__ADD_NAME | DIR__SEARCH;
if (new_dentry->d_inode)
@@ -2485,7 +2493,7 @@ static int selinux_inode_init_security(s
static int selinux_inode_create(struct path *dir, struct dentry *dentry,
int mask)
{
- return may_create(dir->dentry->d_inode, dentry, SECCLASS_FILE);
+ return may_create(dir, dentry, SECCLASS_FILE);
}

static int selinux_inode_link(struct dentry *old_dentry, struct path *dir,
@@ -2496,7 +2504,7 @@ static int selinux_inode_link(struct den
rc = secondary_ops->inode_link(old_dentry, dir, new_dentry);
if (rc)
return rc;
- return may_link(dir->dentry->d_inode, old_dentry, MAY_LINK);
+ return may_link(dir, old_dentry, MAY_LINK);
}

static int selinux_inode_unlink(struct path *dir, struct dentry *dentry)
@@ -2506,24 +2514,24 @@ static int selinux_inode_unlink(struct p
rc = secondary_ops->inode_unlink(dir, dentry);
if (rc)
return rc;
- return may_link(dir->dentry->d_inode, dentry, MAY_UNLINK);
+ return may_link(dir, dentry, MAY_UNLINK);
}

static int selinux_inode_symlink(struct path *dir, struct dentry *dentry,
const char *name)
{
- return may_create(dir->dentry->d_inode, dentry, SECCLASS_LNK_FILE);
+ return may_create(dir, dentry, SECCLASS_LNK_FILE);
}

static int selinux_inode_mkdir(struct path *dir, struct dentry *dentry,
int mask)
{
- return may_create(dir->dentry->d_inode, dentry, SECCLASS_DIR);
+ return may_create(dir, dentry, SECCLASS_DIR);
}

static int selinux_inode_rmdir(struct path *dir, struct dentry *dentry)
{
- return may_link(dir->dentry->d_inode, dentry, MAY_RMDIR);
+ return may_link(dir, dentry, MAY_RMDIR);
}

static int selinux_inode_mknod(struct path *dir, struct dentry *dentry,
@@ -2535,15 +2543,15 @@ static int selinux_inode_mknod(struct pa
if (rc)
return rc;

- return may_create(dir->dentry->d_inode, dentry,
+ return may_create(dir, dentry,
inode_mode_to_security_class(mode));
}

static int selinux_inode_rename(struct path *old_dir, struct dentry *old_dentry,
struct path *new_dir, struct dentry *new_dentry)
{
- return may_rename(old_dir->dentry->d_inode, old_dentry,
- new_dir->dentry->d_inode, new_dentry);
+ return may_rename(old_dir, old_dentry,
+ new_dir, new_dentry);
}

static int selinux_inode_readlink(struct dentry *dentry)
@@ -2658,6 +2666,7 @@ static int selinux_inode_setxattr(struct
return -EPERM;

AVC_AUDIT_DATA_INIT(&ad, FS);
+ ad.u.fs.path.mnt = path->mnt;
ad.u.fs.path.dentry = dentry;

rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,