In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix race condition between session lookup and expire Thread A + Thread B ksmbdsessionlookup | smb2sesssetup sess = xaload | | | xaerase(&conn->sessions, sess->id); | | ksmbdsessiondestroy(sess) --> kfree(sess) | // UAF! | sess->lastactive = jiffies | + This patch add rwsem to fix race condition between ksmbdsessionlookup and ksmbdexpire_session.