If the memory region allocated by KFENCE had previously been poisoned, any validity checks done using kasan_byte_accessible() will fail. Fix it by unpoisoning the memory before using it as the pool region.
Link: https://linux-review.googlesource.com/id/I0af99e9f1c25eaf7e1ec295836b5d148d76940c5 Signed-off-by: Peter Collingbourne <p...@google.com> --- mm/kfence/core.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/mm/kfence/core.c b/mm/kfence/core.c index d53c91f881a4..bb22b0cf77aa 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -633,13 +633,19 @@ static DECLARE_DELAYED_WORK(kfence_timer, toggle_allocation_gate); void __init kfence_alloc_pool(void) { + void *pool; + if (!kfence_sample_interval) return; - __kfence_pool = memblock_alloc(KFENCE_POOL_SIZE, PAGE_SIZE); - - if (!__kfence_pool) + pool = memblock_alloc(KFENCE_POOL_SIZE, PAGE_SIZE); + if (!pool) { pr_err("failed to allocate pool\n"); + return; + } + + kasan_unpoison_range(pool, KFENCE_POOL_SIZE); + __kfence_pool = pool; } void __init kfence_init(void) -- 2.31.0.208.g409f899ff0-goog
