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@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 | 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; }