linux/kernel/bpf
Daniel Borkmann 82f8dd28bd bpf: fix splat for illegal devmap percpu allocation
It was reported that syzkaller was able to trigger a splat on
devmap percpu allocation due to illegal/unsupported allocation
request size passed to __alloc_percpu():

  [   70.094249] illegal size (32776) or align (8) for percpu allocation
  [   70.094256] ------------[ cut here ]------------
  [   70.094259] WARNING: CPU: 3 PID: 3451 at mm/percpu.c:1365 pcpu_alloc+0x96/0x630
  [...]
  [   70.094325] Call Trace:
  [   70.094328]  __alloc_percpu_gfp+0x12/0x20
  [   70.094330]  dev_map_alloc+0x134/0x1e0
  [   70.094331]  SyS_bpf+0x9bc/0x1610
  [   70.094333]  ? selinux_task_setrlimit+0x5a/0x60
  [   70.094334]  ? security_task_setrlimit+0x43/0x60
  [   70.094336]  entry_SYSCALL_64_fastpath+0x1a/0xa5

This was due to too large max_entries for the map such that we
surpassed the upper limit of PCPU_MIN_UNIT_SIZE. It's fine to
fail naturally here, so switch to __alloc_percpu_gfp() and pass
__GFP_NOWARN instead.

Fixes: 11393cc9b9 ("xdp: Add batching support to redirect map")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Shankara Pailoor <sp3485@columbia.edu>
Reported-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-19 13:13:50 +01:00
..
arraymap.c bpf: inline map in map lookup functions for array and htab 2017-08-19 21:56:34 -07:00
bpf_lru_list.c bpf: lru: Lower the PERCPU_NR_SCANS from 16 to 4 2017-04-17 13:55:52 -04:00
bpf_lru_list.h bpf: Only set node->ref = 1 if it has not been set 2017-09-01 09:57:39 -07:00
cgroup.c bpf: BPF support for sock_ops 2017-07-01 16:15:13 -07:00
core.c bpf: fix bpf_tail_call() x64 JIT 2017-10-03 16:04:44 -07:00
devmap.c bpf: fix splat for illegal devmap percpu allocation 2017-10-19 13:13:50 +01:00
hashtab.c bpf: Only set node->ref = 1 if it has not been set 2017-09-01 09:57:39 -07:00
helpers.c bpf: rename ARG_PTR_TO_STACK 2017-01-09 16:56:27 -05:00
inode.c netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1' 2017-10-09 15:18:04 +02:00
lpm_trie.c bpf: Allow selecting numa node during map creation 2017-08-19 21:35:43 -07:00
Makefile bpf: sock_map fixes for !CONFIG_BPF_SYSCALL and !STREAM_PARSER 2017-08-16 15:34:13 -07:00
map_in_map.c bpf: Add syscall lookup support for fd array and htab 2017-06-29 13:13:25 -04:00
map_in_map.h bpf: Add syscall lookup support for fd array and htab 2017-06-29 13:13:25 -04:00
percpu_freelist.c bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
percpu_freelist.h bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
sockmap.c bpf: add support for sockmap detach programs 2017-09-08 21:11:00 -07:00
stackmap.c bpf: Allow selecting numa node during map creation 2017-08-19 21:35:43 -07:00
syscall.c bpf: do not disable/enable BH in bpf_map_free_id() 2017-09-19 15:42:54 -07:00
tnum.c bpf/verifier: track signed and unsigned min/max values 2017-08-08 17:51:34 -07:00
verifier.c bpf: disallow arithmetic operations on context pointer 2017-10-18 13:21:13 +01:00