Re: [PATCH net] bpf: cpumap: use GFP_KERNEL instead of GFP_ATOMIC in __cpu_map_entry_alloc()

[Daniel Borkmann]

On 02/14/2018 03:17 PM, Jason Wang wrote:
> 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@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 0bf7800f1799 ("ptr_ring: try vmalloc() when kmalloc() fails")
> Cc: Michal Hocko <mhocko@xxxxxxxxxx>
> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
> Cc: akpm@xxxxxxxxxxxxxxxxxxxx
> Cc: dhowells@xxxxxxxxxx
> Cc: hannes@xxxxxxxxxxx
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>

Applied to bpf tree, thanks Jason!