diff options
| author | Richard Guy Briggs <rgb@redhat.com> | 2014-03-15 18:42:34 -0400 |
|---|---|---|
| committer | Eric Paris <eparis@redhat.com> | 2014-09-23 16:37:56 -0400 |
| commit | 9eab339b197a6903043d272295dcb716ff739b21 (patch) | |
| tree | 4f8c204a04b59bc20e679f84f1d6b28f79fcce2c | |
| parent | f874738e8c178b19479f7b143211a1df00367988 (diff) | |
| download | linux-9eab339b197a6903043d272295dcb716ff739b21.tar.bz2 | |
audit: 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: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
| -rw-r--r-- | kernel/audit.c | 5 | ||||
| -rw-r--r-- | kernel/auditsc.c | 3 |
2 files changed, 4 insertions, 4 deletions
diff --git a/kernel/audit.c b/kernel/audit.c index 3a80abb6eaa1..53bb39bf79e2 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1850,7 +1850,7 @@ EXPORT_SYMBOL(audit_log_task_context); void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) { const struct cred *cred; - char name[sizeof(tsk->comm)]; + char comm[sizeof(tsk->comm)]; struct mm_struct *mm = tsk->mm; char *tty; @@ -1884,9 +1884,8 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) from_kgid(&init_user_ns, cred->fsgid), tty, audit_get_sessionid(tsk)); - get_task_comm(name, tsk); audit_log_format(ab, " comm="); - audit_log_untrustedstring(ab, name); + audit_log_untrustedstring(ab, get_task_comm(comm, tsk)); if (mm) { down_read(&mm->mmap_sem); diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 63a74a703c97..89335723fb2a 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -2424,6 +2424,7 @@ static void audit_log_task(struct audit_buffer *ab) kgid_t gid; unsigned int sessionid; struct mm_struct *mm = current->mm; + char comm[sizeof(current->comm)]; auid = audit_get_loginuid(current); sessionid = audit_get_sessionid(current); @@ -2436,7 +2437,7 @@ static void audit_log_task(struct audit_buffer *ab) sessionid); audit_log_task_context(ab); audit_log_format(ab, " pid=%d comm=", task_pid_nr(current)); - audit_log_untrustedstring(ab, current->comm); + audit_log_untrustedstring(ab, get_task_comm(comm, current)); if (mm) { down_read(&mm->mmap_sem); if (mm->exe_file) |