From d9105720404c2c35ae79949a06a95ce88ef6280e Mon Sep 17 00:00:00 2001 From: Hou Tao Date: Sat, 11 Nov 2023 12:38:21 +0800 Subject: [PATCH] bpf: Add missed allocation hint for bpf_mem_cache_alloc_flags() [ Upstream commit 75a442581d05edaee168222ffbe00d4389785636 ] bpf_mem_cache_alloc_flags() may call __alloc() directly when there is no free object in free list, but it doesn't initialize the allocation hint for the returned pointer. It may lead to bad memory dereference when freeing the pointer, so fix it by initializing the allocation hint. Fixes: 822fb26bdb55 ("bpf: Add a hint to allocated objects.") Signed-off-by: Hou Tao Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20231111043821.2258513-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- kernel/bpf/memalloc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c index d93ddac283d4..956f80ee6f5c 100644 --- a/kernel/bpf/memalloc.c +++ b/kernel/bpf/memalloc.c @@ -958,6 +958,8 @@ void notrace *bpf_mem_cache_alloc_flags(struct bpf_mem_alloc *ma, gfp_t flags) memcg = get_memcg(c); old_memcg = set_active_memcg(memcg); ret = __alloc(c, NUMA_NO_NODE, GFP_KERNEL | __GFP_NOWARN | __GFP_ACCOUNT); + if (ret) + *(struct bpf_mem_cache **)ret = c; set_active_memcg(old_memcg); mem_cgroup_put(memcg); }