p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

ima: relax requiring a file signature for new files with zero length 

Custom policies can require file signatures based on LSM labels.  These
files are normally created and only afterwards labeled, requiring them
to be signed.

Instead of requiring file signatures based on LSM labels, entire
filesystems could require file signatures.  In this case, we need the
ability of writing new files without requiring file signatures.

The definition of a "new" file was originally defined as any file with
a length of zero.  Subsequent patches redefined a "new" file to be based
on the FILE_CREATE open flag.  By combining the open flag with a file
size of zero, this patch relaxes the file signature requirement.

Fixes: 1ac202e978 ima: accept previously set IMA_NEW_FILE
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This commit is contained in:
Mimi Zohar 2017-11-08 07:38:28 -05:00
parent d21bd68983
commit b7e27bc1d4
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
security/integrity/ima/ima_appraise.c
View File

@ -223,7 +223,8 @@ int ima_appraise_measurement(enum ima_hooks func,
if (opened & FILE_CREATED) if (opened & FILE_CREATED)
iint->flags |= IMA_NEW_FILE; iint->flags |= IMA_NEW_FILE;
if ((iint->flags & IMA_NEW_FILE) && if ((iint->flags & IMA_NEW_FILE) &&
!(iint->flags & IMA_DIGSIG_REQUIRED)) (!(iint->flags & IMA_DIGSIG_REQUIRED) ||
(inode->i_size == 0)))
status = INTEGRITY_PASS; status = INTEGRITY_PASS;
goto out; goto out;
} }