net: filter: seccomp: fix wrong decoding of BPF_S_ANC_SECCOMP_LD_W
authorDaniel Borkmann <dborkman@redhat.com>
Mon, 14 Apr 2014 19:20:12 +0000 (21:20 +0200)
committerDavid S. Miller <davem@davemloft.net>
Mon, 14 Apr 2014 20:26:47 +0000 (16:26 -0400)
commit8c482cdc358ef931ee02262e0a4ef0f29946aa0c
tree1739a3a15955927dd2a0c649d9b44a17ab6982b2
parent2eac7648321f4a08aa4078504d7727af0af7173b
net: filter: seccomp: fix wrong decoding of BPF_S_ANC_SECCOMP_LD_W

While reviewing seccomp code, we found that BPF_S_ANC_SECCOMP_LD_W has
been wrongly decoded by commit a8fc927780 ("sk-filter: Add ability to
get socket filter program (v2)") into the opcode BPF_LD|BPF_B|BPF_ABS
although it should have been decoded as BPF_LD|BPF_W|BPF_ABS.

In practice, this should not have much side-effect though, as such
conversion is/was being done through prctl(2) PR_SET_SECCOMP. Reverse
operation PR_GET_SECCOMP will only return the current seccomp mode, but
not the filter itself. Since the transition to the new BPF infrastructure,
it's also not used anymore, so we can simply remove this as it's
unreachable.

Fixes: a8fc927780 ("sk-filter: Add ability to get socket filter program (v2)")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/linux/filter.h
net/core/filter.c