From: Hou Tao Date: Sat, 11 Nov 2023 04:38:21 +0000 (+0800) Subject: bpf: Add missed allocation hint for bpf_mem_cache_alloc_flags() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=75a442581d05edaee168222ffbe00d4389785636;p=linux.git bpf: Add missed allocation hint for bpf_mem_cache_alloc_flags() 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 --- diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c index 63b909d277d47..6a51cfe4c2d63 100644 --- a/kernel/bpf/memalloc.c +++ b/kernel/bpf/memalloc.c @@ -978,6 +978,8 @@ 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); }