[PATCH 1/5] ima: Set file->f_mode instead of file->f_flags in ima_calc_file_hash()

[Roberto Sassu <roberto.sassu@huawei.com>]

Commit a408e4a86b36 ("ima: open a new file instance if no read
permissions") tries to create a new file descriptor to calculate a file
digest if the file has not been opened with O_RDONLY flag. However, if a
new file descriptor cannot be obtained, it sets the FMODE_READ flag to
file->f_flags instead of file->f_mode.

This patch fixes this issue by replacing f_flags with f_mode as it was
before that commit.

Cc: stable@vger.kernel.org # 4.20.x
Fixes: a408e4a86b36 ("ima: open a new file instance if no read permissions")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 security/integrity/ima/ima_crypto.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 423c84f95a14..8ab17aa867dd 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -436,7 +436,7 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
 			 */
 			pr_info_ratelimited("Unable to reopen file for reading.\n");
 			f = file;
-			f->f_flags |= FMODE_READ;
+			f->f_mode |= FMODE_READ;
 			modified_flags = true;
 		} else {
 			new_file_instance = true;
@@ -456,7 +456,7 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
 	if (new_file_instance)
 		fput(f);
 	else if (modified_flags)
-		f->f_flags &= ~FMODE_READ;
+		f->f_mode &= ~FMODE_READ;
 	return rc;
 }
 
-- 
2.17.1