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| author | Daniel Xu <dxu@dxuuu.xyz> | 2021-07-29 02:09:21 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-08-18 10:06:55 +0300 |
| commit | 621d81cfbb0c4c9fdc2f55245abc323b0ade437e (patch) | |
| tree | e223d941eb1113aa40278d703357c7fac9aa523f /tools | |
| parent | 51f19580f5f4f2393b2a0220dc2495e9abb0efbd (diff) | |
| download | linux-621d81cfbb0c4c9fdc2f55245abc323b0ade437e.tar.xz | |
libbpf: Do not close un-owned FD 0 on errors
[ Upstream commit c34c338a40e4f3b6f80889cd17fd9281784d1c32 ]
Before this patch, btf_new() was liable to close an arbitrary FD 0 if
BTF parsing failed. This was because:
* btf->fd was initialized to 0 through the calloc()
* btf__free() (in the `done` label) closed any FDs >= 0
* btf->fd is left at 0 if parsing fails
This issue was discovered on a system using libbpf v0.3 (without
BTF_KIND_FLOAT support) but with a kernel that had BTF_KIND_FLOAT types
in BTF. Thus, parsing fails.
While this patch technically doesn't fix any issues b/c upstream libbpf
has BTF_KIND_FLOAT support, it'll help prevent issues in the future if
more BTF types are added. It also allow the fix to be backported to
older libbpf's.
Fixes: 3289959b97ca ("libbpf: Support BTF loading and raw data output in both endianness")
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/5969bb991adedb03c6ae93e051fd2a00d293cf25.1627513670.git.dxu@dxuuu.xyz
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/lib/bpf/btf.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index d57e13a13798..1d9e5b35524c 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -805,6 +805,7 @@ static struct btf *btf_new(const void *data, __u32 size, struct btf *base_btf) btf->nr_types = 0; btf->start_id = 1; btf->start_str_off = 0; + btf->fd = -1; if (base_btf) { btf->base_btf = base_btf; @@ -833,8 +834,6 @@ static struct btf *btf_new(const void *data, __u32 size, struct btf *base_btf) if (err) goto done; - btf->fd = -1; - done: if (err) { btf__free(btf); |