bpf: cpumap: use GFP_KERNEL instead of GFP_ATOMIC in __cpu_map_entry_alloc()
authorJason Wang <jasowang@redhat.com>
Wed, 14 Feb 2018 14:17:34 +0000 (22:17 +0800)
committerDaniel Borkmann <daniel@iogearbox.net>
Wed, 14 Feb 2018 14:34:27 +0000 (15:34 +0100)
commit7fc17e909edfb9bf421ee04e981d3d474175c7c7
treefdbe1700e6f5cf29b53901732e850f93ad04f87b
parent952fad8e323975c4e826b659087d2648777594a6
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 <mhocko@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: akpm@linux-foundation.org
Cc: dhowells@redhat.com
Cc: hannes@cmpxchg.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel/bpf/cpumap.c