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| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2022-03-19 11:08:25 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-04-06 20:32:12 +0300 |
| commit | 7b3552d3f9f6897851fc453b5131a967167e43c2 (patch) | |
| tree | b5ff18cf6a04b88de924fde3f31e7551380af4f9 /kernel | |
| parent | 97e6d7dab1ca4648821c790a2b7913d6d5d549db (diff) | |
| download | linux-7b3552d3f9f6897851fc453b5131a967167e43c2.tar.xz | |
bpf: Reject writes for PTR_TO_MAP_KEY in check_helper_mem_access
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>
Diffstat (limited to 'kernel')
| -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 d953e62b5268..9c1a02b82ecd 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4861,6 +4861,11 @@ 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: |