From: Breno Leitao <leit@xxxxxx>
Add support for KASAN in the alloc_caches (apoll and netmsg_cache).
Thus, if something touches the unused caches, it will raise a KASAN
warning/exception.
It poisons the object when the object is put to the cache, and unpoisons
it when the object is gotten or freed.
Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
---
io_uring/alloc_cache.h | 11 ++++++++---
io_uring/io_uring.c | 14 ++++++++++++--
io_uring/net.c | 2 +-
io_uring/net.h | 4 ----
io_uring/poll.c | 2 +-
5 files changed, 22 insertions(+), 11 deletions(-)
diff --git a/io_uring/alloc_cache.h b/io_uring/alloc_cache.h
index ae61eb383cae..6c6bdde6306b 100644
--- a/io_uring/alloc_cache.h
+++ b/io_uring/alloc_cache.h
@@ -16,16 +16,20 @@ static inline bool io_alloc_cache_put(struct io_alloc_cache *cache,
if (cache->nr_cached < IO_ALLOC_CACHE_MAX) {
cache->nr_cached++;
wq_stack_add_head(&entry->node, &cache->list);
+ /* KASAN poisons object */
+ kasan_slab_free_mempool(entry);
return true;
}
return false;
}
-static inline struct io_cache_entry *io_alloc_cache_get(struct io_alloc_cache *cache)
+static inline struct io_cache_entry *io_alloc_cache_get(struct io_alloc_cache *cache,
+ size_t size)
{
if (cache->list.next) {
struct io_cache_entry *entry;
entry = container_of(cache->list.next, struct io_cache_entry, node);
+ kasan_unpoison_range(entry, size);
cache->list.next = cache->list.next->next;
return entry;
}
@@ -40,10 +44,11 @@ static inline void io_alloc_cache_init(struct io_alloc_cache *cache)
}
static inline void io_alloc_cache_free(struct io_alloc_cache *cache,
- void (*free)(struct io_cache_entry *))
+ void (*free)(struct io_cache_entry *),
+ size_t size)
{
while (1) {
- struct io_cache_entry *entry = io_alloc_cache_get(cache);
+ struct io_cache_entry *entry = io_alloc_cache_get(cache, size);
if (!entry)
break;
free(entry);
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 80b6204769e8..01367145689b 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2766,6 +2766,17 @@ static void io_req_caches_free(struct io_ring_ctx *ctx)
mutex_unlock(&ctx->uring_lock);
}
+static __cold void io_uring_acache_free(struct io_ring_ctx *ctx)
+{
+
+ io_alloc_cache_free(&ctx->apoll_cache, io_apoll_cache_free,
+ sizeof(struct async_poll));
+#ifdef CONFIG_NET
+ io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free,
+ sizeof(struct io_async_msghdr));
+#endif
+}
+
static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
{
io_sq_thread_finish(ctx);
@@ -2781,8 +2792,7 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
__io_sqe_files_unregister(ctx);
io_cqring_overflow_kill(ctx);
io_eventfd_unregister(ctx);
- io_alloc_cache_free(&ctx->apoll_cache, io_apoll_cache_free);
- io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free);
+ io_uring_acache_free(ctx);
mutex_unlock(&ctx->uring_lock);
io_destroy_buffers(ctx);
if (ctx->sq_creds)
diff --git a/io_uring/net.c b/io_uring/net.c
index fbc34a7c2743..8dc67b23b030 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -139,7 +139,7 @@ static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req,
struct io_async_msghdr *hdr;
if (!(issue_flags & IO_URING_F_UNLOCKED)) {
- entry = io_alloc_cache_get(&ctx->netmsg_cache);
+ entry = io_alloc_cache_get(&ctx->netmsg_cache, sizeof(struct io_async_msghdr));
if (entry) {
hdr = container_of(entry, struct io_async_msghdr, cache);
hdr->free_iov = NULL;
diff --git a/io_uring/net.h b/io_uring/net.h
index 5ffa11bf5d2e..d8359de84996 100644
--- a/io_uring/net.h
+++ b/io_uring/net.h
@@ -62,8 +62,4 @@ int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
void io_send_zc_cleanup(struct io_kiocb *req);
void io_netmsg_cache_free(struct io_cache_entry *entry);
-#else
-static inline void io_netmsg_cache_free(struct io_cache_entry *entry)
-{
-}
#endif
diff --git a/io_uring/poll.c b/io_uring/poll.c
index 8339a92b4510..295d59875f00 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -661,7 +661,7 @@ static struct async_poll *io_req_alloc_apoll(struct io_kiocb *req,
apoll = req->apoll;
kfree(apoll->double_poll);
} else if (!(issue_flags & IO_URING_F_UNLOCKED)) {
- entry = io_alloc_cache_get(&ctx->apoll_cache);
+ entry = io_alloc_cache_get(&ctx->apoll_cache, sizeof(struct async_poll));
if (entry == NULL)
goto alloc_apoll;
apoll = container_of(entry, struct async_poll, cache);
--
2.30.2
