linux/kernel/bpf
William Tu 63dfef75ed bpf: enable verifier to add 0 to packet ptr
The patch fixes the case when adding a zero value to the packet
pointer.  The zero value could come from src_reg equals type
BPF_K or CONST_IMM.  The patch fixes both, otherwise the verifer
reports the following error:
  [...]
    R0=imm0,min_value=0,max_value=0
    R1=pkt(id=0,off=0,r=4)
    R2=pkt_end R3=fp-12
    R4=imm4,min_value=4,max_value=4
    R5=pkt(id=0,off=4,r=4)
  269: (bf) r2 = r0     // r2 becomes imm0
  270: (77) r2 >>= 3
  271: (bf) r4 = r1     // r4 becomes pkt ptr
  272: (0f) r4 += r2    // r4 += 0
  addition of negative constant to packet pointer is not allowed

Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: Mihai Budiu <mbudiu@vmware.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-06 22:50:04 -05:00
..
arraymap.c bpf: don't trigger OOM killer under pressure with map alloc 2017-01-18 17:12:26 -05:00
bpf_lru_list.c bpf: Make unnecessarily global functions static 2017-01-10 21:00:59 -05:00
bpf_lru_list.h bpf: Add percpu LRU list 2016-11-15 11:50:20 -05:00
cgroup.c bpf: Add new cgroup attach type to enable sock modifications 2016-12-02 13:46:08 -05:00
core.c bpf: add initial bpf tracepoints 2017-01-25 13:17:47 -05:00
hashtab.c bpf: don't trigger OOM killer under pressure with map alloc 2017-01-18 17:12:26 -05:00
helpers.c bpf: rename ARG_PTR_TO_STACK 2017-01-09 16:56:27 -05:00
inode.c bpf: add initial bpf tracepoints 2017-01-25 13:17:47 -05:00
lpm_trie.c bpf, lpm: fix kfree of im_node in trie_update_elem 2017-01-23 21:17:35 -05:00
Makefile bpf: add a longest prefix match trie map implementation 2017-01-23 16:10:38 -05:00
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
stackmap.c bpf: don't trigger OOM killer under pressure with map alloc 2017-01-18 17:12:26 -05:00
syscall.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-28 10:33:06 -05:00
verifier.c bpf: enable verifier to add 0 to packet ptr 2017-02-06 22:50:04 -05:00