4.15-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jason Wang <jasow...@redhat.com> commit 7fc17e909edfb9bf421ee04e981d3d474175c7c7 upstream. 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+1a240cdb1f4cc8881...@syzkaller.appspotmail.com Fixes: 0bf7800f1799 ("ptr_ring: try vmalloc() when kmalloc() fails") Cc: Michal Hocko <mho...@kernel.org> Cc: Daniel Borkmann <dan...@iogearbox.net> Cc: Matthew Wilcox <wi...@infradead.org> Cc: Jesper Dangaard Brouer <bro...@redhat.com> Cc: a...@linux-foundation.org Cc: dhowe...@redhat.com Cc: han...@cmpxchg.org Signed-off-by: Jason Wang <jasow...@redhat.com> Acked-by: Jesper Dangaard Brouer <bro...@redhat.com> Signed-off-by: Daniel Borkmann <dan...@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- kernel/bpf/cpumap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -339,7 +339,7 @@ static int cpu_map_kthread_run(void *dat 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;