diff options
Diffstat (limited to 'mm/Kconfig.debug')
| -rw-r--r-- | mm/Kconfig.debug | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index afc72fde0f03..41a58536531d 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -70,6 +70,38 @@ config SLUB_DEBUG_ON off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying "slab_debug=-". +config SLUB_RCU_DEBUG + bool "Enable UAF detection in TYPESAFE_BY_RCU caches (for KASAN)" + depends on SLUB_DEBUG + # SLUB_RCU_DEBUG should build fine without KASAN, but is currently useless + # without KASAN, so mark it as a dependency of KASAN for now. + depends on KASAN + default KASAN_GENERIC || KASAN_SW_TAGS + help + Make SLAB_TYPESAFE_BY_RCU caches behave approximately as if the cache + was not marked as SLAB_TYPESAFE_BY_RCU and every caller used + kfree_rcu() instead. + + This is intended for use in combination with KASAN, to enable KASAN to + detect use-after-free accesses in such caches. + (KFENCE is able to do that independent of this flag.) + + This might degrade performance. + Unfortunately this also prevents a very specific bug pattern from + triggering (insufficient checks against an object being recycled + within the RCU grace period); so this option can be turned off even on + KASAN builds, in case you want to test for such a bug. + + If you're using this for testing bugs / fuzzing and care about + catching all the bugs WAY more than performance, you might want to + also turn on CONFIG_RCU_STRICT_GRACE_PERIOD. + + WARNING: + This is designed as a debugging feature, not a security feature. + Objects are sometimes recycled without RCU delay under memory pressure. + + If unsure, say N. + config PAGE_OWNER bool "Track page owner" depends on DEBUG_KERNEL && STACKTRACE_SUPPORT |