From f850a7c040d9faafb41bceb0a05d6bb7432c8c7a Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Tue, 12 May 2009 15:13:55 -0400 Subject: [PATCH] IMA: remove read permissions on the ima policy file The IMA policy file does not implement read. Trying to just open/read/close the file will load a blank policy and you cannot then change the policy without a reboot. This removes the read permission from the file so one must at least be attempting to write... Signed-off-by: Eric Paris Acked-by: Mimi Zohar Signed-off-by: James Morris --- security/integrity/ima/ima_fs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index ffbe259..3305a96 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -15,6 +15,7 @@ * implemenents security file system for reporting * current measurement list and IMA statistics */ +#include #include #include #include @@ -283,6 +284,9 @@ static atomic_t policy_opencount = ATOMIC_INIT(1); */ int ima_open_policy(struct inode * inode, struct file * filp) { + /* No point in being allowed to open it if you aren't going to write */ + if (!(filp->f_flags & O_WRONLY)) + return -EACCES; if (atomic_dec_and_test(&policy_opencount)) return 0; return -EBUSY; @@ -349,7 +353,7 @@ int ima_fs_init(void) goto out; ima_policy = securityfs_create_file("policy", - S_IRUSR | S_IRGRP | S_IWUSR, + S_IWUSR, ima_dir, NULL, &ima_measure_policy_ops); if (IS_ERR(ima_policy)) -- 1.8.2.3