Message ID | 874keiaryl.fsf@igel.home |
---|---|
State | New |
Headers | show |
Series | Use __pthread_attr_copy in mq_notify (bug 27896) | expand |
On 6/1/21 2:20 PM, Andreas Schwab wrote: > Make a deep copy of the pthread attribute object to remove a potential > use-after-free issue. LGTM Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org> > --- > NEWS | 4 ++++ > sysdeps/unix/sysv/linux/mq_notify.c | 15 ++++++++++----- > 2 files changed, 14 insertions(+), 5 deletions(-) > > diff --git a/NEWS b/NEWS > index 266837bf2d..4460752df7 100644 > --- a/NEWS > +++ b/NEWS > @@ -56,6 +56,10 @@ Security related changes: > potentially resulting in degraded service or Denial of Service on the > local system. Reported by Chris Schanzle. > > + CVE-2021-33574: The mq_notify function has a potential use-after-free > + issue when using a notification type of SIGEV_THREAD and a thread > + attribute with a non-default affinity mask. > + > The following bugs are resolved with this release: > > [The release manager will add the list generated by > diff --git a/sysdeps/unix/sysv/linux/mq_notify.c b/sysdeps/unix/sysv/linux/mq_notify.c > index cc575a0cdd..f7ddfe5a6c 100644 > --- a/sysdeps/unix/sysv/linux/mq_notify.c > +++ b/sysdeps/unix/sysv/linux/mq_notify.c > @@ -133,8 +133,11 @@ helper_thread (void *arg) > (void) __pthread_barrier_wait (¬ify_barrier); > } > else if (data.raw[NOTIFY_COOKIE_LEN - 1] == NOTIFY_REMOVED) > - /* The only state we keep is the copy of the thread attributes. */ > - free (data.attr); > + { > + /* The only state we keep is the copy of the thread attributes. */ > + pthread_attr_destroy (data.attr); > + free (data.attr); > + } > } > return NULL; > } > @@ -255,8 +258,7 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification) > if (data.attr == NULL) > return -1; > > - memcpy (data.attr, notification->sigev_notify_attributes, > - sizeof (pthread_attr_t)); > + __pthread_attr_copy (data.attr, notification->sigev_notify_attributes); > } > > /* Construct the new request. */ > @@ -270,7 +272,10 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification) > > /* If it failed, free the allocated memory. */ > if (__glibc_unlikely (retval != 0)) > - free (data.attr); > + { > + pthread_attr_destroy (data.attr); > + free (data.attr); > + } > > return retval; > } >
diff --git a/NEWS b/NEWS index 266837bf2d..4460752df7 100644 --- a/NEWS +++ b/NEWS @@ -56,6 +56,10 @@ Security related changes: potentially resulting in degraded service or Denial of Service on the local system. Reported by Chris Schanzle. + CVE-2021-33574: The mq_notify function has a potential use-after-free + issue when using a notification type of SIGEV_THREAD and a thread + attribute with a non-default affinity mask. + The following bugs are resolved with this release: [The release manager will add the list generated by diff --git a/sysdeps/unix/sysv/linux/mq_notify.c b/sysdeps/unix/sysv/linux/mq_notify.c index cc575a0cdd..f7ddfe5a6c 100644 --- a/sysdeps/unix/sysv/linux/mq_notify.c +++ b/sysdeps/unix/sysv/linux/mq_notify.c @@ -133,8 +133,11 @@ helper_thread (void *arg) (void) __pthread_barrier_wait (¬ify_barrier); } else if (data.raw[NOTIFY_COOKIE_LEN - 1] == NOTIFY_REMOVED) - /* The only state we keep is the copy of the thread attributes. */ - free (data.attr); + { + /* The only state we keep is the copy of the thread attributes. */ + pthread_attr_destroy (data.attr); + free (data.attr); + } } return NULL; } @@ -255,8 +258,7 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification) if (data.attr == NULL) return -1; - memcpy (data.attr, notification->sigev_notify_attributes, - sizeof (pthread_attr_t)); + __pthread_attr_copy (data.attr, notification->sigev_notify_attributes); } /* Construct the new request. */ @@ -270,7 +272,10 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification) /* If it failed, free the allocated memory. */ if (__glibc_unlikely (retval != 0)) - free (data.attr); + { + pthread_attr_destroy (data.attr); + free (data.attr); + } return retval; }