Commit fdb2410f authored by Mimi Zohar's avatar Mimi Zohar
Browse files

ima: define ima_post_create_tmpfile() hook and add missing call 



If tmpfiles can be made persistent, then newly created tmpfiles need to
be treated like any other new files in policy.

This patch indicates which newly created tmpfiles are in policy, causing
the file hash to be calculated on __fput().

Reported-by: default avatarIgnaz Forster <ignaz.forster@gmx.de>
[rgoldwyn@suse.com: Call ima_post_create_tmpfile() in vfs_tmpfile() as
opposed to do_tmpfile(). This will help the case for overlayfs where
copy_up is denied while overwriting a file.]
Signed-off-by: default avatarGoldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: default avatarMimi Zohar <zohar@linux.ibm.com>
parent c8b37524

fs/namei.c

+1 −0
Original line number Diff line number Diff line
@@ -3462,6 +3462,7 @@ struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag) 
		inode->i_state |= I_LINKABLE;

		spin_unlock(&inode->i_lock);

	}

	ima_post_create_tmpfile(inode);

	return child;



out_err:

include/linux/ima.h

+5 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ struct linux_binprm; 
#ifdef CONFIG_IMA

extern int ima_bprm_check(struct linux_binprm *bprm);

extern int ima_file_check(struct file *file, int mask);

extern void ima_post_create_tmpfile(struct inode *inode);

extern void ima_file_free(struct file *file);

extern int ima_file_mmap(struct file *file, unsigned long prot);

extern int ima_load_data(enum kernel_load_data_id id);
@@ -56,6 +57,10 @@ static inline int ima_file_check(struct file *file, int mask) 
	return 0;

}



static inline void ima_post_create_tmpfile(struct inode *inode)

{

}



static inline void ima_file_free(struct file *file)

{

	return;

security/integrity/ima/ima_main.c

+33 −2
Original line number Diff line number Diff line
@@ -396,6 +396,33 @@ int ima_file_check(struct file *file, int mask) 
}

EXPORT_SYMBOL_GPL(ima_file_check);



/**

 * ima_post_create_tmpfile - mark newly created tmpfile as new

 * @file : newly created tmpfile

 *

 * No measuring, appraising or auditing of newly created tmpfiles is needed.

 * Skip calling process_measurement(), but indicate which newly, created

 * tmpfiles are in policy.

 */

void ima_post_create_tmpfile(struct inode *inode)

{

	struct integrity_iint_cache *iint;

	int must_appraise;



	must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);

	if (!must_appraise)

		return;



	/* Nothing to do if we can't allocate memory */

	iint = integrity_inode_get(inode);

	if (!iint)

		return;



	/* needed for writing the security xattrs */

	set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);

	iint->ima_file_status = INTEGRITY_PASS;

}



/**

 * ima_post_path_mknod - mark as a new inode

 * @dentry: newly created dentry
@@ -413,8 +440,12 @@ void ima_post_path_mknod(struct dentry *dentry) 
	if (!must_appraise)

		return;



	/* Nothing to do if we can't allocate memory */

	iint = integrity_inode_get(inode);

	if (iint)

	if (!iint)

		return;



	/* needed for re-opening empty files */

	iint->flags |= IMA_NEW_FILE;

}

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