Commit 9975a54b authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller

bpf: fix bpf_prog_get_info_by_fd to dump correct xlated_prog_len

bpf_prog_size(prog->len) is not the correct length we want to dump
back to user space. The code in bpf_prog_get_info_by_fd() uses this
to copy prog->insnsi to user space, but bpf_prog_size(prog->len) also
includes the size of struct bpf_prog itself plus program instructions
and is usually used either in context of accounting or for bpf_prog_alloc()
et al, thus we copy out of bounds in bpf_prog_get_info_by_fd()
potentially. Use the correct bpf_prog_insn_size() instead.

Fixes: 1e270976 ("bpf: Add BPF_OBJ_GET_INFO_BY_FD")
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent efe967cd
...@@ -1312,7 +1312,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, ...@@ -1312,7 +1312,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
} }
ulen = info.xlated_prog_len; ulen = info.xlated_prog_len;
info.xlated_prog_len = bpf_prog_size(prog->len); info.xlated_prog_len = bpf_prog_insn_size(prog);
if (info.xlated_prog_len && ulen) { if (info.xlated_prog_len && ulen) {
uinsns = u64_to_user_ptr(info.xlated_prog_insns); uinsns = u64_to_user_ptr(info.xlated_prog_insns);
ulen = min_t(u32, info.xlated_prog_len, ulen); ulen = min_t(u32, info.xlated_prog_len, ulen);
......
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