diff options
| author | Viktor Malik <vmalik@redhat.com> | 2025-01-29 08:18:57 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-02-03 03:33:51 -0800 |
| commit | 0053f7d39d491b6138d7c526876d13885cbb65f1 (patch) | |
| tree | 927ece76c07fe08a6f706520f96e30146a37c312 | |
| parent | cb3ade567816a03d1ac1c33bf86073574efcfcaf (diff) | |
bpftool: Fix readlink usage in get_fd_type
The `readlink(path, buf, sizeof(buf))` call reads at most sizeof(buf)
bytes and *does not* append null-terminator to buf. With respect to
that, fix two pieces in get_fd_type:
1. Change the truncation check to contain sizeof(buf) rather than
sizeof(path).
2. Append null-terminator to buf.
Reported by Coverity.
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20250129071857.75182-1-vmalik@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/bpf/bpftool/common.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index 9b75639434b8..0a764426d935 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -461,10 +461,11 @@ int get_fd_type(int fd) p_err("can't read link type: %s", strerror(errno)); return -1; } - if (n == sizeof(path)) { + if (n == sizeof(buf)) { p_err("can't read link type: path too long!"); return -1; } + buf[n] = '\0'; if (strstr(buf, "bpf-map")) return BPF_OBJ_MAP; |