GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-07-22 23:04:43 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

bpf: Restrict bpf when kernel lockdown is in confidentiality mode

Browse source 
bpf_read() and bpf_read_str() could potentially be abused to (eg) allow
private keys in kernel memory to be leaked. Disable them if the kernel
has been locked down in confidentiality mode.

Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
cc: netdev@vger.kernel.org
cc: Chun-Yi Lee <jlee@suse.com>
cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
David Howells 2019-08-19 17:17:59 -07:00 • committed by James Morris
parent a94549dd87
commit 9d1f8be5cf
3 changed files with 12 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

10
kernel/trace/bpf_trace.c
View file

@ -139,8 +139,13 @@ BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr)
{
int ret;
ret = security_locked_down(LOCKDOWN_BPF_READ);
if (ret < 0)
goto out;
ret = probe_kernel_read(dst, unsafe_ptr, size);
if (unlikely(ret < 0))
out:
memset(dst, 0, size);
return ret;
@ -566,6 +571,10 @@ BPF_CALL_3(bpf_probe_read_str, void *, dst, u32, size,
{
int ret;
ret = security_locked_down(LOCKDOWN_BPF_READ);
if (ret < 0)
goto out;
/*
* The strncpy_from_unsafe() call will likely not fill the entire
* buffer, but that's okay in this circumstance as we're probing
@ -577,6 +586,7 @@ BPF_CALL_3(bpf_probe_read_str, void *, dst, u32, size,
*/
ret = strncpy_from_unsafe(dst, unsafe_ptr, size);
if (unlikely(ret < 0))
out:
memset(dst, 0, size);
return ret;