On Tue, Feb 25, 2025 at 4:31 PM Blaise Boscaccy <bboscaccy@xxxxxxxxxxxxxxxxxxx> wrote: > > Certain bpf syscall subcommands are available for usage from both > userspace and the kernel. LSM modules or eBPF gatekeeper programs may > need to take a different course of action depending on whether or not > a BPF syscall originated from the kernel or userspace. > > Additionally, some of the bpf_attr struct fields contain pointers to > arbitrary memory. Currently the functionality to determine whether or > not a pointer refers to kernel memory or userspace memory is exposed > to the bpf verifier, but that information is missing from various LSM > hooks. > > Here we augment the LSM hooks to provide this data, by simply passing > the corresponding universal pointer in any hook that contains already > contains a bpf_attr struct that corresponds to a subcommand that may > be called from the kernel. I think this information is useful for LSM hooks. Question: Do we need a full bpfptr_t for these hooks, or just a boolean "is_kernel or not"? Thanks, Song > Signed-off-by: Blaise Boscaccy <bboscaccy@xxxxxxxxxxxxxxxxxxx>
