From: Jason Wang Date: Wed, 14 Feb 2018 14:17:34 +0000 (+0800) Subject: bpf: cpumap: use GFP_KERNEL instead of GFP_ATOMIC in __cpu_map_entry_alloc() X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=7fc17e909edfb9bf421ee04e981d3d474175c7c7;p=openwrt%2Fstaging%2Fblogic.git bpf: cpumap: use GFP_KERNEL instead of GFP_ATOMIC in __cpu_map_entry_alloc() There're several implications after commit 0bf7800f1799 ("ptr_ring: try vmalloc() when kmalloc() fails") with the using of vmalloc() since can't allow GFP_ATOMIC but mandate GFP_KERNEL. This will lead a WARN since cpumap try to call with GFP_ATOMIC. Fortunately, entry allocation of cpumap can only be done through syscall path which means GFP_ATOMIC is not necessary, so fixing this by replacing GFP_ATOMIC with GFP_KERNEL. Reported-by: syzbot+1a240cdb1f4cc88819df@syzkaller.appspotmail.com Fixes: 0bf7800f1799 ("ptr_ring: try vmalloc() when kmalloc() fails") Cc: Michal Hocko Cc: Daniel Borkmann Cc: Matthew Wilcox Cc: Jesper Dangaard Brouer Cc: akpm@linux-foundation.org Cc: dhowells@redhat.com Cc: hannes@cmpxchg.org Signed-off-by: Jason Wang Acked-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann --- diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index fbfdada6caee..a4bb0b34375a 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -334,7 +334,7 @@ static int cpu_map_kthread_run(void *data) static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu, int map_id) { - gfp_t gfp = GFP_ATOMIC|__GFP_NOWARN; + gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; struct bpf_cpu_map_entry *rcpu; int numa, err;