Description
In the Linux kernel, the following vulnerability has been resolved: net: shaper: rework the VALID marking (again) Recent commit changed the semantics from NOT_VALID to VALID. I didn't realize that the flags are not stored atomically with the entry in XArray. There's still a race of reader observing a VALID mark for a slot, getting interrupted, writer replacing the entry with a different one, reader continuing, fetching the entry which is now a different pointer than the pointer for which VALID was meant. The biggest consequence of this is that we may see a UAF since net_shaper_rollback() assumed that entries without VALID can be freed without observing RCU. Looks like the XArray marks are buying us nothing at this point. Let's convert the code to an explicit valid field. The smp_load_acquire() / smp_store_release() barriers are marginally cleaner.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
93954b40f6a4fc43226c01a15b02732f884500f1 to < 2417df5e7bb4184b9d3a2988036bf2c46e594545affected93954b40f6a4fc43226c01a15b02732f884500f1 to < 96ea960dd40fd55302e0fd755176f26a95e6a50caffected93954b40f6a4fc43226c01a15b02732f884500f1 to < b8d7519352ba8c6df83259295d4a3bad093cae90affected
Linux Linux
Default version status: affected
6.13affected0 to < 6.13unaffected6.18.34 to ≤ 6.18.*unaffected7.0.11 to ≤ 7.0.*unaffected7.1 to ≤ *unaffected