提交 b151d6b0 编写于 作者: D Dmitry Kasatkin 提交者: Mimi Zohar

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 dff6efc3 "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: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>  3.14+
上级 1f100979
......@@ -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;
}
......
......@@ -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);
}
......
......@@ -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)
......
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