Vulnerability details

In the Linux kernel, the following vulnerability has been resolved: OPP: Fix race between OPP addition and lookup A race exists between dev_pm_opp_add_dynamic() and dev_pm_opp_find_freq_exact(): CPU0 (add) CPU1 (lookup) ------------------------------- ------------------------------ _opp_add() mutex_lock() list_add(&new_opp->node, head) mutex_unlock() _opp_table_find_key() mutex_lock() dev_pm_opp_get(opp) kref_get() mutex_unlock() kref_init(&new_opp->kref) dev_pm_opp_put() kref_put_mutex() The newly added OPP is inserted into the list before its kref is initialized. A concurrent lookup can find this OPP and increment its reference count while it is still uninitialized, leading to refcount corruption and a potential premature free. Fix this by initializing ->kref and ->opp_table before making the OPP visible via list_add(). This ensures any concurrent lookup observes a fully initialized object. [ Viresh: Updated commit log ]

• https://git.kernel.org/stable/c/835b9b5b4d287a03c713680b0231d36ff599201b
• https://git.kernel.org/stable/c/2fb061a90898420d8ca1a0b9959ca977d90fa841
• https://git.kernel.org/stable/c/e25be5d812ec8ca2615d23726b3861b04e2fff35
• https://git.kernel.org/stable/c/932ebfad767be1395946cbc1727a7c38eeee3d24
• https://git.kernel.org/stable/c/1946ea2f6b3ec00e313c78e83fc196f1f6aba2a9
• https://git.kernel.org/stable/c/46696b0b2123475d7f95909435c09808fc5ffd23
• https://git.kernel.org/stable/c/bb75bd7d9ae7672034f73ce67a57e6ac89bb39e5
• https://git.kernel.org/stable/c/f5e1cc9a284bff2510981643a5bca4bc4c21b81a