diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/helpers.c | 17 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 10 |
2 files changed, 20 insertions, 7 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 50da680c479f..ad7a0573f71b 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -163,17 +163,26 @@ static u64 bpf_get_current_comm(u64 r1, u64 size, u64 r3, u64 r4, u64 r5) struct task_struct *task = current; char *buf = (char *) (long) r1; - if (!task) - return -EINVAL; + if (unlikely(!task)) + goto err_clear; - strlcpy(buf, task->comm, min_t(size_t, size, sizeof(task->comm))); + strncpy(buf, task->comm, size); + + /* Verifier guarantees that size > 0. For task->comm exceeding + * size, guarantee that buf is %NUL-terminated. Unconditionally + * done here to save the size test. + */ + buf[size - 1] = 0; return 0; +err_clear: + memset(buf, 0, size); + return -EINVAL; } const struct bpf_func_proto bpf_get_current_comm_proto = { .func = bpf_get_current_comm, .gpl_only = false, .ret_type = RET_INTEGER, - .arg1_type = ARG_PTR_TO_STACK, + .arg1_type = ARG_PTR_TO_RAW_STACK, .arg2_type = ARG_CONST_STACK_SIZE, }; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 413ec5614180..685587885374 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -62,17 +62,21 @@ EXPORT_SYMBOL_GPL(trace_call_bpf); static u64 bpf_probe_read(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) { void *dst = (void *) (long) r1; - int size = (int) r2; + int ret, size = (int) r2; void *unsafe_ptr = (void *) (long) r3; - return probe_kernel_read(dst, unsafe_ptr, size); + ret = probe_kernel_read(dst, unsafe_ptr, size); + if (unlikely(ret < 0)) + memset(dst, 0, size); + + return ret; } static const struct bpf_func_proto bpf_probe_read_proto = { .func = bpf_probe_read, .gpl_only = true, .ret_type = RET_INTEGER, - .arg1_type = ARG_PTR_TO_STACK, + .arg1_type = ARG_PTR_TO_RAW_STACK, .arg2_type = ARG_CONST_STACK_SIZE, .arg3_type = ARG_ANYTHING, }; |