From d47be3dfecaf20255af89a57460285c82d5271ad Mon Sep 17 00:00:00 2001 From: David Quigley Date: Wed, 22 May 2013 12:50:34 -0400 Subject: Security: Add hook to calculate context based on a negative dentry. There is a time where we need to calculate a context without the inode having been created yet. To do this we take the negative dentry and calculate a context based on the process and the parent directory contexts. Acked-by: Eric Paris Acked-by: James Morris Signed-off-by: Matthew N. Dodd Signed-off-by: Miguel Rodel Felipe Signed-off-by: Phua Eu Gene Signed-off-by: Khin Mi Mi Aung Signed-off-by: Steve Dickson Signed-off-by: Trond Myklebust --- security/selinux/hooks.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'security/selinux') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 5c6f2cd2d095..b1f7bd727bd9 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2515,6 +2515,40 @@ static void selinux_inode_free_security(struct inode *inode) inode_free_security(inode); } +static int selinux_dentry_init_security(struct dentry *dentry, int mode, + struct qstr *name, void **ctx, + u32 *ctxlen) +{ + const struct cred *cred = current_cred(); + struct task_security_struct *tsec; + struct inode_security_struct *dsec; + struct superblock_security_struct *sbsec; + struct inode *dir = dentry->d_parent->d_inode; + u32 newsid; + int rc; + + tsec = cred->security; + dsec = dir->i_security; + sbsec = dir->i_sb->s_security; + + if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { + newsid = tsec->create_sid; + } else { + rc = security_transition_sid(tsec->sid, dsec->sid, + inode_mode_to_security_class(mode), + name, + &newsid); + if (rc) { + printk(KERN_WARNING + "%s: security_transition_sid failed, rc=%d\n", + __func__, -rc); + return rc; + } + } + + return security_sid_to_context(newsid, (char **)ctx, ctxlen); +} + static int selinux_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, char **name, void **value, size_t *len) @@ -5562,6 +5596,7 @@ static struct security_operations selinux_ops = { .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts, .sb_parse_opts_str = selinux_parse_opts_str, + .dentry_init_security = selinux_dentry_init_security, .inode_alloc_security = selinux_inode_alloc_security, .inode_free_security = selinux_inode_free_security, -- cgit v1.2.3