[PATCH] audit: copy comm to avoid race in string printing

From: Richard Guy Briggs
Date: Sat Mar 15 2014 - 19:30:28 EST


---
kernel/audit.c | 5 ++---
kernel/auditsc.c | 3 ++-
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/audit.c b/kernel/audit.c
index 9239e5e..ecb08a5 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1883,7 +1883,7 @@ 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;

@@ -1917,9 +1917,8 @@ 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, memcpy(comm, tsk->comm, sizeof(comm));

if (mm) {
down_read(&mm->mmap_sem);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 8fffca8..dcddadd 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2434,6 +2434,7 @@ static void audit_log_task(struct audit_buffer *ab)
kuid_t auid, uid;
kgid_t gid;
unsigned int sessionid;
+ char comm[sizeof(current->comm)];
struct mm_struct *mm = current->mm;

auid = audit_get_loginuid(current);
@@ -2447,7 +2448,7 @@ 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, memcpy(comm, current->comm, sizeof(comm));
if (mm) {
down_read(&mm->mmap_sem);
if (mm->exe_file)
--
1.7.1

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