iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

xdp: use trusted arguments in XDP hints kfuncs

Browse Source 
Currently, verifier does not reject XDP programs that pass NULL pointer to
hints functions. At the same time, this case is not handled in any driver
implementation (including veth). For example, changing

bpf_xdp_metadata_rx_timestamp(ctx, &timestamp);

to

bpf_xdp_metadata_rx_timestamp(ctx, NULL);

in xdp_metadata test successfully crashes the system.

Add KF_TRUSTED_ARGS flag to hints kfunc definitions, so driver code
does not have to worry about getting invalid pointers.

Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs")
Reported-by: Stanislav Fomichev <sdf@google.com>
Closes: https://lore.kernel.org/bpf/ZKWo0BbpLfkZHbyE@google.com/
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230711105930.29170-1-larysa.zaremba@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Larysa Zaremba 2023-07-11 12:59:26 +02:00 committed by Alexei Starovoitov
parent 4369016497
commit 2e06c57d66
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
net/core/xdp.c
View File

@ -741,7 +741,7 @@ __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash,
__diag_pop();
BTF_SET8_START(xdp_metadata_kfunc_ids)
#define XDP_METADATA_KFUNC(_, name) BTF_ID_FLAGS(func, name, 0)
#define XDP_METADATA_KFUNC(_, name) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)
XDP_METADATA_KFUNC_xxx
#undef XDP_METADATA_KFUNC
BTF_SET8_END(xdp_metadata_kfunc_ids)