diff options
| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2022-03-19 13:38:25 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-06 08:47:57 +0200 |
| commit | 70674d11d14eeecad90be4b409a22b902112ba32 (patch) | |
| tree | 8eca8a891a91f18086d45cbe942ca9859e4a56c8 | |
| parent | b9037efc1f3483cfa459e59f803989a6cee4a8da (diff) | |
bpf: Reject writes for PTR_TO_MAP_KEY in check_helper_mem_access
commit 7b3552d3f9f6897851fc453b5131a967167e43c2 upstream.
It is not permitted to write to PTR_TO_MAP_KEY, but the current code in
check_helper_mem_access would allow for it, reject this case as well, as
helpers taking ARG_PTR_TO_UNINIT_MEM also take PTR_TO_MAP_KEY.
Fixes: 69c087ba6225 ("bpf: Add bpf_for_each_map_elem() helper")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220319080827.73251-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/bpf/verifier.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index a39eedecc93a..df3ed68cf79d 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4832,6 +4832,11 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno, return check_packet_access(env, regno, reg->off, access_size, zero_size_allowed); case PTR_TO_MAP_KEY: + if (meta && meta->raw_mode) { + verbose(env, "R%d cannot write into %s\n", regno, + reg_type_str(env, reg->type)); + return -EACCES; + } return check_mem_region_access(env, regno, reg->off, access_size, reg->map_ptr->key_size, false); case PTR_TO_MAP_VALUE: |