From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 162FA38DE9 for ; Wed, 31 Jul 2024 20:28:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722457710; cv=none; b=BiG11ShF57MhbbWNwtdkmaRs2m3ZKK9ZDR7XBqlgPa/4RRaTNkhWFhsws6gaSMQ8MPuP/bfOevhFnDHf6jg5eEfPmtaS67kv/8ZBGjmr4h/85top9UNaIhgaBq41bk/5tf0KiWTOpKreN5w1uMyD9RprzkqGjoXR/WmJ+ZhpoZ8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722457710; c=relaxed/simple; bh=zxihI8mt9lkISThbBGy1F7JpcGD/0RGXyozhgbjDdck=; h=Date:To:From:Subject:Message-Id; b=ebbHJ/ks93+VWa6B/5tuBHSCLmv7jg9lqpPsRY8upXCFK8ggj/CHquwC84Z48tsklPDwdjJkHfwT7KeCvsn9KzzyFLrppCQckb9nX2mj+gvL6w3L2PmQIxpa6lVXNT7bWK3DzIn7mz9KkCIEYzhI5RVtosP1ZePee/xKj9h6vlM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=yJ0XvxBl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="yJ0XvxBl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C86F6C116B1; Wed, 31 Jul 2024 20:28:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1722457709; bh=zxihI8mt9lkISThbBGy1F7JpcGD/0RGXyozhgbjDdck=; h=Date:To:From:Subject:From; b=yJ0XvxBl5eZE/nBoKUtZG2EWe94ILP3sCmIx+78oAHOOtCO5ovQBicFQ4v/IewCZu P0dCux2mlYWqYxqK6cL5ZS/OU0smf5DHkHpwNQYYvT7ALkCu+d5/lF6Dz5BNw0u7RF brpmx0rJ6uJXTL5cXkPWQRAm5BQs6EBPePEy8VNw= Date: Wed, 31 Jul 2024 13:28:29 -0700 To: mm-commits@vger.kernel.org,vbabka@suse.cz,shakeel.butt@linux.dev,nphamcs@gmail.com,hannes@cmpxchg.org,songmuchun@bytedance.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-list_lru-fix-uaf-for-memory-cgroup.patch added to mm-hotfixes-unstable branch Message-Id: <20240731202829.C86F6C116B1@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: list_lru: fix UAF for memory cgroup has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-list_lru-fix-uaf-for-memory-cgroup.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-list_lru-fix-uaf-for-memory-cgroup.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Muchun Song Subject: mm: list_lru: fix UAF for memory cgroup Date: Thu, 18 Jul 2024 16:36:07 +0800 The mem_cgroup_from_slab_obj() is supposed to be called under rcu lock or cgroup_mutex or others which could prevent returned memcg from being freed. Fix it by adding missing rcu read lock. Found by code inspection. Link: https://lkml.kernel.org/r/20240718083607.42068-1-songmuchun@bytedance.com Fixes: 0a97c01cd20bb ("list_lru: allow explicit memcg and NUMA node selection) Signed-off-by: Muchun Song Acked-by: Shakeel Butt Cc: Johannes Weiner Cc: Nhat Pham Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/list_lru.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) --- a/mm/list_lru.c~mm-list_lru-fix-uaf-for-memory-cgroup +++ a/mm/list_lru.c @@ -85,6 +85,7 @@ list_lru_from_memcg_idx(struct list_lru } #endif /* CONFIG_MEMCG */ +/* The caller must ensure the memcg lifetime. */ bool list_lru_add(struct list_lru *lru, struct list_head *item, int nid, struct mem_cgroup *memcg) { @@ -109,14 +110,20 @@ EXPORT_SYMBOL_GPL(list_lru_add); bool list_lru_add_obj(struct list_lru *lru, struct list_head *item) { + bool ret; int nid = page_to_nid(virt_to_page(item)); - struct mem_cgroup *memcg = list_lru_memcg_aware(lru) ? - mem_cgroup_from_slab_obj(item) : NULL; + struct mem_cgroup *memcg; - return list_lru_add(lru, item, nid, memcg); + rcu_read_lock(); + memcg = list_lru_memcg_aware(lru) ? mem_cgroup_from_slab_obj(item) : NULL; + ret = list_lru_add(lru, item, nid, memcg); + rcu_read_unlock(); + + return ret; } EXPORT_SYMBOL_GPL(list_lru_add_obj); +/* The caller must ensure the memcg lifetime. */ bool list_lru_del(struct list_lru *lru, struct list_head *item, int nid, struct mem_cgroup *memcg) { @@ -139,11 +146,16 @@ EXPORT_SYMBOL_GPL(list_lru_del); bool list_lru_del_obj(struct list_lru *lru, struct list_head *item) { + bool ret; int nid = page_to_nid(virt_to_page(item)); - struct mem_cgroup *memcg = list_lru_memcg_aware(lru) ? - mem_cgroup_from_slab_obj(item) : NULL; + struct mem_cgroup *memcg; + + rcu_read_lock(); + memcg = list_lru_memcg_aware(lru) ? mem_cgroup_from_slab_obj(item) : NULL; + ret = list_lru_del(lru, item, nid, memcg); + rcu_read_unlock(); - return list_lru_del(lru, item, nid, memcg); + return ret; } EXPORT_SYMBOL_GPL(list_lru_del_obj); _ Patches currently in -mm which might be from songmuchun@bytedance.com are mm-list_lru-fix-uaf-for-memory-cgroup.patch mm-kmem-remove-mem_cgroup_from_obj.patch