->d_name.name can change on rename and the earlier value can be freed; there are conditions sufficient to stabilize it (->d_lock on dentry, ->d_lock on its parent, ->i_rwsem exclusive on the parent's inode, rename_lock), but none of those are met at any of the sites. Take a stable snapshot of the name instead.
Link: https://lore.kernel.org/all/20240202182732.GE2087318@ZenIV/ Signed-off-by: Al Viro <[email protected]> Signed-off-by: Stefan Berger <[email protected]> --- security/integrity/ima/ima_api.c | 16 ++++++++++++---- security/integrity/ima/ima_template_lib.c | 17 ++++++++++++++--- 2 files changed, 26 insertions(+), 7 deletions(-) diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index b37d043d5748..1856981e33df 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -245,8 +245,8 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file, const char *audit_cause = "failed"; struct inode *inode = file_inode(file); struct inode *real_inode = d_real_inode(file_dentry(file)); - const char *filename = file->f_path.dentry->d_name.name; struct ima_max_digest_data hash; + struct name_snapshot filename; struct kstat stat; int result = 0; int length; @@ -317,9 +317,13 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file, if (file->f_flags & O_DIRECT) audit_cause = "failed(directio)"; + take_dentry_name_snapshot(&filename, file->f_path.dentry); + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, - filename, "collect_data", audit_cause, - result, 0); + filename.name.name, "collect_data", + audit_cause, result, 0); + + release_dentry_name_snapshot(&filename); } return result; } @@ -432,6 +436,7 @@ void ima_audit_measurement(struct ima_iint_cache *iint, */ const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf) { + struct name_snapshot filename; char *pathname = NULL; *pathbuf = __getname(); @@ -445,7 +450,10 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf) } if (!pathname) { - strscpy(namebuf, path->dentry->d_name.name, NAME_MAX); + take_dentry_name_snapshot(&filename, path->dentry); + strscpy(namebuf, filename.name.name, NAME_MAX); + release_dentry_name_snapshot(&filename); + pathname = namebuf; } diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c index 6cd0add524cd..3b2cb8f1002e 100644 --- a/security/integrity/ima/ima_template_lib.c +++ b/security/integrity/ima/ima_template_lib.c @@ -483,7 +483,10 @@ static int ima_eventname_init_common(struct ima_event_data *event_data, bool size_limit) { const char *cur_filename = NULL; + struct name_snapshot filename; u32 cur_filename_len = 0; + bool snapshot = false; + int ret; BUG_ON(event_data->filename == NULL && event_data->file == NULL); @@ -496,7 +499,10 @@ static int ima_eventname_init_common(struct ima_event_data *event_data, } if (event_data->file) { - cur_filename = event_data->file->f_path.dentry->d_name.name; + take_dentry_name_snapshot(&filename, + event_data->file->f_path.dentry); + snapshot = true; + cur_filename = filename.name.name; cur_filename_len = strlen(cur_filename); } else /* @@ -505,8 +511,13 @@ static int ima_eventname_init_common(struct ima_event_data *event_data, */ cur_filename_len = IMA_EVENT_NAME_LEN_MAX; out: - return ima_write_template_field_data(cur_filename, cur_filename_len, - DATA_FMT_STRING, field_data); + ret = ima_write_template_field_data(cur_filename, cur_filename_len, + DATA_FMT_STRING, field_data); + + if (snapshot) + release_dentry_name_snapshot(&filename); + + return ret; } /* -- 2.43.0
