diff options
Diffstat (limited to 'kernel/trace/bpf_trace.c')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 187 |
1 files changed, 137 insertions, 50 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index f50bf19f7a05..ffc91d4935ac 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -138,24 +138,125 @@ static const struct bpf_func_proto bpf_override_return_proto = { }; #endif -BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr) +BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, + const void __user *, unsafe_ptr) { - int ret; + int ret = probe_user_read(dst, unsafe_ptr, size); - ret = security_locked_down(LOCKDOWN_BPF_READ); - if (ret < 0) - goto out; + if (unlikely(ret < 0)) + memset(dst, 0, size); + + return ret; +} + +static const struct bpf_func_proto bpf_probe_read_user_proto = { + .func = bpf_probe_read_user, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_UNINIT_MEM, + .arg2_type = ARG_CONST_SIZE_OR_ZERO, + .arg3_type = ARG_ANYTHING, +}; + +BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, + const void __user *, unsafe_ptr) +{ + int ret = strncpy_from_unsafe_user(dst, unsafe_ptr, size); + + if (unlikely(ret < 0)) + memset(dst, 0, size); + + return ret; +} + +static const struct bpf_func_proto bpf_probe_read_user_str_proto = { + .func = bpf_probe_read_user_str, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_UNINIT_MEM, + .arg2_type = ARG_CONST_SIZE_OR_ZERO, + .arg3_type = ARG_ANYTHING, +}; - ret = probe_kernel_read(dst, unsafe_ptr, size); +static __always_inline int +bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr, + const bool compat) +{ + int ret = security_locked_down(LOCKDOWN_BPF_READ); + + if (unlikely(ret < 0)) + goto out; + ret = compat ? probe_kernel_read(dst, unsafe_ptr, size) : + probe_kernel_read_strict(dst, unsafe_ptr, size); if (unlikely(ret < 0)) out: memset(dst, 0, size); + return ret; +} + +BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, + const void *, unsafe_ptr) +{ + return bpf_probe_read_kernel_common(dst, size, unsafe_ptr, false); +} + +static const struct bpf_func_proto bpf_probe_read_kernel_proto = { + .func = bpf_probe_read_kernel, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_UNINIT_MEM, + .arg2_type = ARG_CONST_SIZE_OR_ZERO, + .arg3_type = ARG_ANYTHING, +}; + +BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, + const void *, unsafe_ptr) +{ + return bpf_probe_read_kernel_common(dst, size, unsafe_ptr, true); +} + +static const struct bpf_func_proto bpf_probe_read_compat_proto = { + .func = bpf_probe_read_compat, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_UNINIT_MEM, + .arg2_type = ARG_CONST_SIZE_OR_ZERO, + .arg3_type = ARG_ANYTHING, +}; + +static __always_inline int +bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr, + const bool compat) +{ + int ret = security_locked_down(LOCKDOWN_BPF_READ); + if (unlikely(ret < 0)) + goto out; + /* + * The strncpy_from_unsafe_*() call will likely not fill the entire + * buffer, but that's okay in this circumstance as we're probing + * arbitrary memory anyway similar to bpf_probe_read_*() and might + * as well probe the stack. Thus, memory is explicitly cleared + * only in error case, so that improper users ignoring return + * code altogether don't copy garbage; otherwise length of string + * is returned that can be used for bpf_perf_event_output() et al. + */ + ret = compat ? strncpy_from_unsafe(dst, unsafe_ptr, size) : + strncpy_from_unsafe_strict(dst, unsafe_ptr, size); + if (unlikely(ret < 0)) +out: + memset(dst, 0, size); return ret; } -static const struct bpf_func_proto bpf_probe_read_proto = { - .func = bpf_probe_read, +BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, + const void *, unsafe_ptr) +{ + return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr, false); +} + +static const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { + .func = bpf_probe_read_kernel_str, .gpl_only = true, .ret_type = RET_INTEGER, .arg1_type = ARG_PTR_TO_UNINIT_MEM, @@ -163,7 +264,22 @@ static const struct bpf_func_proto bpf_probe_read_proto = { .arg3_type = ARG_ANYTHING, }; -BPF_CALL_3(bpf_probe_write_user, void *, unsafe_ptr, const void *, src, +BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, + const void *, unsafe_ptr) +{ + return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr, true); +} + +static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { + .func = bpf_probe_read_compat_str, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_UNINIT_MEM, + .arg2_type = ARG_CONST_SIZE_OR_ZERO, + .arg3_type = ARG_ANYTHING, +}; + +BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, u32, size) { /* @@ -186,10 +302,8 @@ BPF_CALL_3(bpf_probe_write_user, void *, unsafe_ptr, const void *, src, return -EPERM; if (unlikely(!nmi_uaccess_okay())) return -EPERM; - if (!access_ok(unsafe_ptr, size)) - return -EPERM; - return probe_kernel_write(unsafe_ptr, src, size); + return probe_user_write(unsafe_ptr, src, size); } static const struct bpf_func_proto bpf_probe_write_user_proto = { @@ -585,41 +699,6 @@ static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { .arg2_type = ARG_ANYTHING, }; -BPF_CALL_3(bpf_probe_read_str, void *, dst, u32, size, - const void *, unsafe_ptr) -{ - int ret; - - ret = security_locked_down(LOCKDOWN_BPF_READ); - if (ret < 0) - goto out; - - /* - * The strncpy_from_unsafe() call will likely not fill the entire - * buffer, but that's okay in this circumstance as we're probing - * arbitrary memory anyway similar to bpf_probe_read() and might - * as well probe the stack. Thus, memory is explicitly cleared - * only in error case, so that improper users ignoring return - * code altogether don't copy garbage; otherwise length of string - * is returned that can be used for bpf_perf_event_output() et al. - */ - ret = strncpy_from_unsafe(dst, unsafe_ptr, size); - if (unlikely(ret < 0)) -out: - memset(dst, 0, size); - - return ret; -} - -static const struct bpf_func_proto bpf_probe_read_str_proto = { - .func = bpf_probe_read_str, - .gpl_only = true, - .ret_type = RET_INTEGER, - .arg1_type = ARG_PTR_TO_UNINIT_MEM, - .arg2_type = ARG_CONST_SIZE_OR_ZERO, - .arg3_type = ARG_ANYTHING, -}; - struct send_signal_irq_work { struct irq_work irq_work; struct task_struct *task; @@ -699,8 +778,6 @@ tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_map_pop_elem_proto; case BPF_FUNC_map_peek_elem: return &bpf_map_peek_elem_proto; - case BPF_FUNC_probe_read: - return &bpf_probe_read_proto; case BPF_FUNC_ktime_get_ns: return &bpf_ktime_get_ns_proto; case BPF_FUNC_tail_call: @@ -727,8 +804,18 @@ tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_current_task_under_cgroup_proto; case BPF_FUNC_get_prandom_u32: return &bpf_get_prandom_u32_proto; + case BPF_FUNC_probe_read_user: + return &bpf_probe_read_user_proto; + case BPF_FUNC_probe_read_kernel: + return &bpf_probe_read_kernel_proto; + case BPF_FUNC_probe_read: + return &bpf_probe_read_compat_proto; + case BPF_FUNC_probe_read_user_str: + return &bpf_probe_read_user_str_proto; + case BPF_FUNC_probe_read_kernel_str: + return &bpf_probe_read_kernel_str_proto; case BPF_FUNC_probe_read_str: - return &bpf_probe_read_str_proto; + return &bpf_probe_read_compat_str_proto; #ifdef CONFIG_CGROUPS case BPF_FUNC_get_current_cgroup_id: return &bpf_get_current_cgroup_id_proto; |