From b151d6b00bbb798c58f2f21305e7d43fa763f34f Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Fri, 27 Jun 2014 18:04:27 +0300 Subject: [PATCH] ima: provide flag to identify new empty files On ima_file_free(), newly created empty files are not labeled with an initial security.ima value, because the iversion did not change. Commit dff6efc "fs: fix iversion handling" introduced a change in iversion behavior. To verify this change use the shell command: $ (exec >foo) $ getfattr -h -e hex -d -m security foo This patch defines the IMA_NEW_FILE flag. The flag is initially set, when IMA detects that a new file is created, and subsequently checked on the ima_file_free() hook to set the initial security.ima value. Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar Cc: 3.14+ --- security/integrity/ima/ima_appraise.c | 7 +++++-- security/integrity/ima/ima_main.c | 12 +++++++----- security/integrity/integrity.h | 1 + 3 files changed, 13 insertions(+), 7 deletions(-) diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 86bfd5c5df85..a4605d677248 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -202,8 +202,11 @@ int ima_appraise_measurement(int func, struct integrity_iint_cache *iint, goto out; cause = "missing-hash"; - status = - (inode->i_size == 0) ? INTEGRITY_PASS : INTEGRITY_NOLABEL; + status = INTEGRITY_NOLABEL; + if (inode->i_size == 0) { + iint->flags |= IMA_NEW_FILE; + status = INTEGRITY_PASS; + } goto out; } diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 2917f980bf30..0a2298f90c9c 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -124,11 +124,13 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint, return; mutex_lock(&inode->i_mutex); - if (atomic_read(&inode->i_writecount) == 1 && - iint->version != inode->i_version) { - iint->flags &= ~IMA_DONE_MASK; - if (iint->flags & IMA_APPRAISE) - ima_update_xattr(iint, file); + if (atomic_read(&inode->i_writecount) == 1) { + if ((iint->version != inode->i_version) || + (iint->flags & IMA_NEW_FILE)) { + iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE); + if (iint->flags & IMA_APPRAISE) + ima_update_xattr(iint, file); + } } mutex_unlock(&inode->i_mutex); } diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 19b8e314ca96..904e68abd49e 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -31,6 +31,7 @@ #define IMA_DIGSIG 0x01000000 #define IMA_DIGSIG_REQUIRED 0x02000000 #define IMA_PERMIT_DIRECTIO 0x04000000 +#define IMA_NEW_FILE 0x08000000 #define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \ IMA_APPRAISE_SUBMASK) -- 2.20.1