This is a note to let you know that I've just added the patch titled io_uring: fix poll/netmsg alloc caches to the 6.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-fix-poll-netmsg-alloc-caches.patch and it can be found in the queue-6.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From fd30d1cdcc4ff405fc54765edf2e11b03f2ed4f3 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov <asml.silence@xxxxxxxxx> Date: Thu, 30 Mar 2023 06:52:38 -0600 Subject: io_uring: fix poll/netmsg alloc caches From: Pavel Begunkov <asml.silence@xxxxxxxxx> commit fd30d1cdcc4ff405fc54765edf2e11b03f2ed4f3 upstream. We increase cache->nr_cached when we free into the cache but don't decrease when we take from it, so in some time we'll get an empty cache with cache->nr_cached larger than IO_ALLOC_CACHE_MAX, that fails io_alloc_cache_put() and effectively disables caching. Fixes: 9b797a37c4bd8 ("io_uring: add abstraction around apoll cache") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- io_uring/alloc_cache.h | 1 + 1 file changed, 1 insertion(+) --- a/io_uring/alloc_cache.h +++ b/io_uring/alloc_cache.h @@ -27,6 +27,7 @@ static inline struct io_cache_entry *io_ struct hlist_node *node = cache->list.first; hlist_del(node); + cache->nr_cached--; return container_of(node, struct io_cache_entry, node); } Patches currently in stable-queue which might be from asml.silence@xxxxxxxxx are queue-6.2/io_uring-fix-poll-netmsg-alloc-caches.patch queue-6.2/io_uring-rsrc-fix-rogue-rsrc-node-grabbing.patch