diff options
| author | Jakub Sitnicki <jakub@cloudflare.com> | 2025-09-01 15:27:43 +0200 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2025-09-04 13:42:29 -0700 |
| commit | 54728bd535fb3899ad51489dc1e05eb5bb53cb95 (patch) | |
| tree | 3e6b9bc51c7885da533790dbc30fec656553f089 | |
| parent | 7f7a958a6a2c9f0e2e82eaffdb5965238c735591 (diff) | |
| download | bpf-next-skb-meta-dynptr.tar.gz | |
bpf: Return an error pointer for skb metadata when CONFIG_NET=nskb-meta-dynptr
Kernel Test Robot reported a compiler warning - a null pointer may be
passed to memmove in __bpf_dynptr_{read,write} when building without
networking support.
The warning is correct from a static analysis standpoint, but not actually
reachable. Without CONFIG_NET, creating dynptrs to skb metadata is
impossible since the constructor kfunc is missing.
Silence the false-postive diagnostic message by returning an error pointer
from bpf_skb_meta_pointer stub when CONFIG_NET=n.
Fixes: 6877cd392bae ("bpf: Enable read/write access to skb metadata through a dynptr")
Closes: https://lore.kernel.org/oe-kbuild-all/202508212031.ir9b3B6Q-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250901-dynptr-skb-meta-no-net-v2-1-ce607fcb6091@cloudflare.com
| -rw-r--r-- | include/linux/filter.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index 9ed21b65e2e968..af6d9354662c78 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1822,7 +1822,7 @@ static inline void bpf_xdp_copy_buf(struct xdp_buff *xdp, unsigned long off, voi static inline void *bpf_skb_meta_pointer(struct sk_buff *skb, u32 offset) { - return NULL; + return ERR_PTR(-EOPNOTSUPP); } #endif /* CONFIG_NET */ |