diff options
| -rw-r--r-- | include/uapi/linux/io_uring/bpf_filter.h | 8 | ||||
| -rw-r--r-- | io_uring/bpf_filter.c | 65 |
2 files changed, 56 insertions, 17 deletions
diff --git a/include/uapi/linux/io_uring/bpf_filter.h b/include/uapi/linux/io_uring/bpf_filter.h index 220351b81bc0..1b461d792a7b 100644 --- a/include/uapi/linux/io_uring/bpf_filter.h +++ b/include/uapi/linux/io_uring/bpf_filter.h @@ -35,13 +35,19 @@ enum { * If set, any currently unset opcode will have a deny filter attached */ IO_URING_BPF_FILTER_DENY_REST = 1, + /* + * If set, if kernel and application don't agree on pdu_size for + * the given opcode, fail the registration of the filter. + */ + IO_URING_BPF_FILTER_SZ_STRICT = 2, }; struct io_uring_bpf_filter { __u32 opcode; /* io_uring opcode to filter */ __u32 flags; __u32 filter_len; /* number of BPF instructions */ - __u32 resv; + __u8 pdu_size; /* expected pdu size for opcode */ + __u8 resv[3]; __u64 filter_ptr; /* pointer to BPF filter */ __u64 resv2[5]; }; diff --git a/io_uring/bpf_filter.c b/io_uring/bpf_filter.c index 8ac7d06de122..28a23e92ee81 100644 --- a/io_uring/bpf_filter.c +++ b/io_uring/bpf_filter.c @@ -308,36 +308,69 @@ err: return ERR_PTR(-EBUSY); } -#define IO_URING_BPF_FILTER_FLAGS IO_URING_BPF_FILTER_DENY_REST +#define IO_URING_BPF_FILTER_FLAGS (IO_URING_BPF_FILTER_DENY_REST | \ + IO_URING_BPF_FILTER_SZ_STRICT) -int io_register_bpf_filter(struct io_restriction *res, - struct io_uring_bpf __user *arg) +static int io_bpf_filter_import(struct io_uring_bpf *reg, + struct io_uring_bpf __user *arg) { - struct io_bpf_filters *filters, *old_filters = NULL; - struct io_bpf_filter *filter, *old_filter; - struct io_uring_bpf reg; - struct bpf_prog *prog; - struct sock_fprog fprog; + const struct io_issue_def *def; int ret; - if (copy_from_user(®, arg, sizeof(reg))) + if (copy_from_user(reg, arg, sizeof(*reg))) return -EFAULT; - if (reg.cmd_type != IO_URING_BPF_CMD_FILTER) + if (reg->cmd_type != IO_URING_BPF_CMD_FILTER) return -EINVAL; - if (reg.cmd_flags || reg.resv) + if (reg->cmd_flags || reg->resv) return -EINVAL; - if (reg.filter.opcode >= IORING_OP_LAST) + if (reg->filter.opcode >= IORING_OP_LAST) return -EINVAL; - if (reg.filter.flags & ~IO_URING_BPF_FILTER_FLAGS) + if (reg->filter.flags & ~IO_URING_BPF_FILTER_FLAGS) return -EINVAL; - if (reg.filter.resv) + if (!mem_is_zero(reg->filter.resv, sizeof(reg->filter.resv))) return -EINVAL; - if (!mem_is_zero(reg.filter.resv2, sizeof(reg.filter.resv2))) + if (!mem_is_zero(reg->filter.resv2, sizeof(reg->filter.resv2))) return -EINVAL; - if (!reg.filter.filter_len || reg.filter.filter_len > BPF_MAXINSNS) + if (!reg->filter.filter_len || reg->filter.filter_len > BPF_MAXINSNS) return -EINVAL; + /* Verify filter size */ + def = &io_issue_defs[array_index_nospec(reg->filter.opcode, IORING_OP_LAST)]; + + /* same size, always ok */ + ret = 0; + if (reg->filter.pdu_size == def->filter_pdu_size) + ; + /* size differs, fail in strict mode */ + else if (reg->filter.flags & IO_URING_BPF_FILTER_SZ_STRICT) + ret = -EMSGSIZE; + /* userspace filter is bigger, always disallow */ + else if (reg->filter.pdu_size > def->filter_pdu_size) + ret = -EMSGSIZE; + + /* copy back kernel filter size */ + reg->filter.pdu_size = def->filter_pdu_size; + if (copy_to_user(&arg->filter, ®->filter, sizeof(reg->filter))) + return -EFAULT; + + return ret; +} + +int io_register_bpf_filter(struct io_restriction *res, + struct io_uring_bpf __user *arg) +{ + struct io_bpf_filters *filters, *old_filters = NULL; + struct io_bpf_filter *filter, *old_filter; + struct io_uring_bpf reg; + struct bpf_prog *prog; + struct sock_fprog fprog; + int ret; + + ret = io_bpf_filter_import(®, arg); + if (ret) + return ret; + fprog.len = reg.filter.filter_len; fprog.filter = u64_to_user_ptr(reg.filter.filter_ptr); |