diff options
| author | Amery Hung <ameryhung@gmail.com> | 2026-02-09 15:01:34 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-02-13 14:14:27 -0800 |
| commit | 04999b99e81eaa7b6223ec1c03af3bcb4ac57aaa (patch) | |
| tree | daed62d6c22ce41e01edfeb9272872bbc484ac2d | |
| parent | 728ff167910ef16e97717719c749ddf4064c653b (diff) | |
libbpf: Fix invalid write loop logic in bpf_linker__add_buf()
Fix bpf_linker__add_buf()'s logic of copying data from memory buffer into
memfd. In the event of short write not writing entire buf_sz bytes into memfd
file, we'll append bytes from the beginning of buf *again* (corrupting ELF
file contents) instead of correctly appending the rest of not-yet-read buf
contents.
Closes: https://github.com/libbpf/libbpf/issues/945
Fixes: 6d5e5e5d7ce1 ("libbpf: Extend linker API to support in-memory ELF files")
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20260209230134.3530521-1-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/lib/bpf/linker.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c index f4403e3cf994..78f92c39290a 100644 --- a/tools/lib/bpf/linker.c +++ b/tools/lib/bpf/linker.c @@ -581,7 +581,7 @@ int bpf_linker__add_buf(struct bpf_linker *linker, void *buf, size_t buf_sz, written = 0; while (written < buf_sz) { - ret = write(fd, buf, buf_sz); + ret = write(fd, buf + written, buf_sz - written); if (ret < 0) { ret = -errno; pr_warn("failed to write '%s': %s\n", filename, errstr(ret)); |