[PATCH] bsdacct: delete timer with sync intension

Vitaliy Gusev
2010-03-25T14:30:11Z

acct_exit_ns --> acct_file_reopen deletes timer without
check timer execution on other CPUs. So acct_timeout() can
change an unmapped memory.

Signed-off-by: Vitaliy Gusev <vgusev@openvz.org>

---
kernel/acct.c | 17 +++++++++--------
1 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/kernel/acct.c b/kernel/acct.c
index a6605ca..6ac80ca 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -353,17 +353,18 @@ restart:

void acct_exit_ns(struct pid_namespace *ns)
{
- struct bsd_acct_struct *acct;
+ struct bsd_acct_struct *acct = ns->bacct;

- spin_lock(&acct_lock);
- acct = ns->bacct;
- if (acct != NULL) {
- if (acct->file != NULL)
- acct_file_reopen(acct, NULL, NULL);
+ if (acct == NULL)
+ return;

- kfree(acct);
- }
+ del_timer_sync(&acct->timer);
+ spin_lock(&acct_lock);
+ if (acct->file != NULL)
+ acct_file_reopen(acct, NULL, NULL);
spin_unlock(&acct_lock);
+
+ kfree(acct);
}

/*