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| author |   Leo Yan <leo.yan@linaro.org> | 2019-07-02 18:25:31 +0800 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2019-07-03 12:17:29 +0200 |
| commit | 33bae185f74d49a0d7b1bfaafb8e959efce0f243 (patch) | |
| tree | 267fab5843b79dcbc9dde80e5038f9b55334b8a2 | |
| parent | libbpf: fix GCC8 warning for strncpy (diff) | |
| download | linux-dev-33bae185f74d49a0d7b1bfaafb8e959efce0f243.tar.xz linux-dev-33bae185f74d49a0d7b1bfaafb8e959efce0f243.zip | |
bpf, libbpf, smatch: Fix potential NULL pointer dereference
Based on the following report from Smatch, fix the potential NULL
pointer dereference check:
tools/lib/bpf/libbpf.c:3493
bpf_prog_load_xattr() warn: variable dereferenced before check 'attr'
(see line 3483)
3479 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
3480 struct bpf_object **pobj, int *prog_fd)
3481 {
3482 struct bpf_object_open_attr open_attr = {
3483 .file = attr->file,
3484 .prog_type = attr->prog_type,
^^^^^^
3485 };
At the head of function, it directly access 'attr' without checking
if it's NULL pointer. This patch moves the values assignment after
validating 'attr' and 'attr->file'.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 6e6ebef11ba3..4907997289e9 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3872,10 +3872,7 @@ int bpf_prog_load(const char *file, enum bpf_prog_type type, int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, struct bpf_object **pobj, int *prog_fd) { - struct bpf_object_open_attr open_attr = { - .file = attr->file, - .prog_type = attr->prog_type, - }; + struct bpf_object_open_attr open_attr = {}; struct bpf_program *prog, *first_prog = NULL; enum bpf_attach_type expected_attach_type; enum bpf_prog_type prog_type; @@ -3888,6 +3885,9 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, if (!attr->file) return -EINVAL; + open_attr.file = attr->file; + open_attr.prog_type = attr->prog_type; + obj = bpf_object__open_xattr(&open_attr); if (IS_ERR_OR_NULL(obj)) return -ENOENT; |