From 217b6dc298156bdb0d6aea9ea93e7e394a5ff091 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Tue, 1 Jun 2021 17:51:41 +0200 Subject: [PATCH] Fix use of __pthread_attr_copy in mq_notify (bug 27896) __pthread_attr_copy can fail and does not initialize the attribute structure in that case. If __pthread_attr_copy is never called and there is no allocated attribute, pthread_attr_destroy should not be called, otherwise there is a null pointer dereference in rt/tst-mqueue6. Fixes commit 42d359350510506b87101cf77202fefcbfc790cb ("Use __pthread_attr_copy in mq_notify (bug 27896)"). Reviewed-by: Siddhesh Poyarekar Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=commit;h=217b6dc298156bdb0d6aea9ea93e7e394a5ff091] CVE: CVE-2021-33574 Reviewed-by: Siddhesh Poyarekar Signed-off-by: Khairul Rohaizzat Jamaluddin --- sysdeps/unix/sysv/linux/mq_notify.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/sysdeps/unix/sysv/linux/mq_notify.c b/sysdeps/unix/sysv/linux/mq_notify.c index f7ddfe5a6c..6f46d29d1d 100644 --- a/sysdeps/unix/sysv/linux/mq_notify.c +++ b/sysdeps/unix/sysv/linux/mq_notify.c @@ -258,7 +258,14 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification) if (data.attr == NULL) return -1; - __pthread_attr_copy (data.attr, notification->sigev_notify_attributes); + int ret = __pthread_attr_copy (data.attr, + notification->sigev_notify_attributes); + if (ret != 0) + { + free (data.attr); + __set_errno (ret); + return -1; + } } /* Construct the new request. */ @@ -271,7 +278,7 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification) int retval = INLINE_SYSCALL (mq_notify, 2, mqdes, &se); /* If it failed, free the allocated memory. */ - if (__glibc_unlikely (retval != 0)) + if (retval != 0 && data.attr != NULL) { pthread_attr_destroy (data.attr); free (data.attr); -- 2.27.0