Re: [PATCH] integrity: get comm using lock to avoid race in string printing

When task->comm is passed directly to audit_log_untrustedstring() without getting a copy or using the task_lock, there is a race that could happen that would output a NULL (\0) in the output string that would effectively truncate the rest of the report text after the comm= field in the audit, losing fields. Use get_task_comm() to get a copy while acquiring the task_lock to prevent this and to prevent the result from being a mixture of old and new values of comm. Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; --- security/integrity/integrity_audit.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c index 85253b5..11706a2 100644 --- a/security/integrity/integrity_audit.c +++ b/security/integrity/integrity_audit.c @@ -33,6 +33,7 @@ void integrity_audit_msg(int audit_msgno, struct inode *inode, const char *cause, int result, int audit_info) { struct audit_buffer *ab; + char comm[sizeof(current->comm)]; if (!integrity_audit_info && audit_info == 1) /* Skip info messages */ return; @@ -49,7 +50,7 @@ void integrity_audit_msg(int audit_msgno, struct inode *inode, audit_log_format(ab, " cause="); audit_log_string(ab, cause); audit_log_format(ab, " comm="); - audit_log_untrustedstring(ab, current->comm); + audit_log_untrustedstring(ab, get_task_comm(comm, current)); if (fname) { audit_log_format(ab, " name="); audit_log_untrustedstring(ab, fname);