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.
Changelog
v1:
- fix comment for f_mode change (suggested by Mimi)
- rename modified_flags variable to modified_mode (suggested by Mimi)
Cc: stable@xxxxxxxxxxxxxxx # 4.20.x
Fixes: a408e4a86b36 ("ima: open a new file instance if no read permissions")
Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
---
security/integrity/ima/ima_crypto.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 5201f5ec2ce4..f3a7f4eb1fc1 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -537,7 +537,7 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
loff_t i_size;
int rc;
struct file *f = file;
- bool new_file_instance = false, modified_flags = false;
+ bool new_file_instance = false, modified_mode = false;
/*
* For consistency, fail file's opened with the O_DIRECT flag on
@@ -557,13 +557,13 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
f = dentry_open(&file->f_path, flags, file->f_cred);
if (IS_ERR(f)) {
/*
- * Cannot open the file again, lets modify f_flags
+ * Cannot open the file again, lets modify f_mode
* of original and continue
*/
pr_info_ratelimited("Unable to reopen file for reading.\n");
f = file;
- f->f_flags |= FMODE_READ;
- modified_flags = true;
+ f->f_mode |= FMODE_READ;
+ modified_mode = true;
} else {
new_file_instance = true;
}
@@ -581,8 +581,8 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
out:
if (new_file_instance)
fput(f);
- else if (modified_flags)
- f->f_flags &= ~FMODE_READ;
+ else if (modified_mode)
+ f->f_mode &= ~FMODE_READ;
return rc;
}
--
2.17.1
