| commit | faa74a862a9442233bff39a496013a74775fb660 | |
| author | Daniel Borkmann <daniel@iogearbox.net> | |
| Tue, 30 Jan 2018 02:37:46 +0000 (30 03:37 +0100) | ||
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| Sat, 3 Feb 2018 16:04:25 +0000 (3 17:04 +0100) | ||
| tree | ad882018cca3e743e493ec556bc589d06732e42e | treesnapshot (tar.gz zip) |
| parent | 02662601a231f8721930168ce71d84bcfb8d9a96 | commitdiff |
bpf: reject stores into ctx via st and xadd
[ upstream commit f37a8cb84cce18762e8f86a70bd6a49a66ab964c ]
Alexei found that verifier does not reject stores into context
via BPF_ST instead of BPF_STX. And while looking at it, we
also should not allow XADD variant of BPF_STX.
The context rewriter is only assuming either BPF_LDX_MEM- or
BPF_STX_MEM-type operations, thus reject anything other than
that so that assumptions in the rewriter properly hold. Add
test cases as well for BPF selftests.
Fixes: d691f9e8d440 ("bpf: allow programs to write to certain skb fields")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ upstream commit f37a8cb84cce18762e8f86a70bd6a49a66ab964c ]
Alexei found that verifier does not reject stores into context
via BPF_ST instead of BPF_STX. And while looking at it, we
also should not allow XADD variant of BPF_STX.
The context rewriter is only assuming either BPF_LDX_MEM- or
BPF_STX_MEM-type operations, thus reject anything other than
that so that assumptions in the rewriter properly hold. Add
test cases as well for BPF selftests.
Fixes: d691f9e8d440 ("bpf: allow programs to write to certain skb fields")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| kernel/bpf/verifier.c | diffblobblamehistory |