CVE-2024-27005

In the Linux kernel, the following vulnerability has been resolved:
interconnect: Don’t access req_list while it’s being manipulated The
icc_lock mutex was split into separate icc_lock and icc_bw_lock mutexes in
[1] to avoid lockdep splats. However, this didn’t adequately protect access
to icc_node::req_list. The icc_set_bw() function will eventually iterate
over req_list while only holding icc_bw_lock, but req_list can be modified
while only holding icc_lock. This causes races between icc_set_bw(),
of_icc_get(), and icc_put(). Example A: CPU0 CPU1 ---- ----
icc_set_bw(path_a) mutex_lock(&icc_bw_lock); icc_put(path_b)
mutex_lock(&icc_lock); aggregate_requests() hlist_for_each_entry(r, …
hlist_del(… <r = invalid pointer> Example B: CPU0 CPU1 ---- ----
icc_set_bw(path_a) mutex_lock(&icc_bw_lock); path_b = of_icc_get()
of_icc_get_by_index() mutex_lock(&icc_lock); path_find() path_init()
aggregate_requests() hlist_for_each_entry(r, … hlist_add_head(… <r =
invalid pointer> Fix this by ensuring icc_bw_lock is always held before
manipulating icc_node::req_list. The additional places icc_bw_lock is held
don’t perform any memory allocations, so we should still be safe from the
original lockdep splats that motivated the separate locks. [1] commit
af42269c3523 (“interconnect: Fix locking for runpm vs reclaim”)