diff options
| -rw-r--r-- | kernel/trace/ring_buffer.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 077d6940af0c..76fed01f1c49 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -657,6 +657,15 @@ static bool rb_is_static(struct ring_buffer_per_cpu *cpu_buffer) return cpu_buffer->user_mapped || cpu_buffer->remote || cpu_buffer->ring_meta; } +static unsigned long rb_static_max_pages(void) +{ + /* + * Static ring buffers are using bpage::id and must account for the + * reader page. + */ + return (1UL << 30) - 1; +} + struct ring_buffer_iter { struct ring_buffer_per_cpu *cpu_buffer; unsigned long head; @@ -2838,6 +2847,8 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, size = end - buffers_start; size = size / nr_cpu_ids; + if (size < sizeof(struct ring_buffer_cpu_meta)) + goto fail_free_buffers; /* * The number of sub-buffers (nr_pages) is determined by the * total size allocated minus the meta data size. @@ -2847,6 +2858,10 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, */ nr_pages = (size - sizeof(struct ring_buffer_cpu_meta)) / (subbuf_size + sizeof(int)); + + if (nr_pages > rb_static_max_pages()) + goto fail_free_buffers; + /* Need at least two pages plus the reader page */ if (nr_pages < 3) goto fail_free_buffers; @@ -2879,6 +2894,10 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, /* The writer is remote. This ring-buffer is read-only */ atomic_inc(&buffer->record_disabled); nr_pages = desc->nr_page_va - 1; + + if (nr_pages > rb_static_max_pages()) + goto fail_free_buffers; + if (nr_pages < 2) goto fail_free_buffers; } else { @@ -7841,6 +7860,9 @@ int ring_buffer_map(struct trace_buffer *buffer, int cpu, /* prevent another thread from changing buffer/sub-buffer sizes */ guard(mutex)(&buffer->mutex); + if (cpu_buffer->nr_pages > rb_static_max_pages()) + return -E2BIG; + err = rb_alloc_meta_page(cpu_buffer); if (err) return err; |