From ea890d0339df46091952413bc39870731131c4c3 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 22 Jan 2019 14:06:49 -0600 Subject: [PATCH] UPSTREAM: 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: Ignaz Forster [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.] Change-Id: I194c0e11dd5dc0f986b131f05471b3e45c0e0df2 Signed-off-by: Goldwyn Rodrigues Signed-off-by: Mimi Zohar --- fs/namei.c | 1 + include/linux/ima.h | 5 +++++ security/integrity/ima/ima_main.c | 35 +++++++++++++++++++++++++++++-- 3 files changed, 39 insertions(+), 2 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index ea9e472179d7..ef741e36acf6 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3605,6 +3605,7 @@ 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: diff --git a/include/linux/ima.h b/include/linux/ima.h index 32b52835ffd5..4b11b4a97e5d 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -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 reqprot, unsigned long prot, unsigned long flags); @@ -43,6 +44,10 @@ 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; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 12890eaaa51d..7a9a3733b138 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -411,6 +411,33 @@ 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 @@ -428,9 +455,13 @@ 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) - iint->flags |= IMA_NEW_FILE; + if (!iint) + return; + + /* needed for re-opening empty files */ + iint->flags |= IMA_NEW_FILE; } /**