diff options
| author | Zheng Yejian <zhengyejian1@huawei.com> | 2023-04-14 09:17:29 +0200 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-04-26 02:11:26 +0200 |
| commit | 625ed52717603f0de4c8b5cf163a3bba5cd9a362 (patch) | |
| tree | 669b7075e58c1dc3ba3d04c92234430a0ceac8b4 /kernel | |
| parent | tracing: Unbreak user events (diff) | |
| download | linux-625ed52717603f0de4c8b5cf163a3bba5cd9a362.tar.xz linux-625ed52717603f0de4c8b5cf163a3bba5cd9a362.zip | |
ring-buffer: Clearly check null ptr returned by rb_set_head_page()
In error case, 'buffer_page' returned by rb_set_head_page() is NULL,
currently check '&buffer_page->list' is equivalent to check 'buffer_page'
due to 'list' is the first member of 'buffer_page', but suppose it is not
some time, 'head_page' would be wild memory while check would be bypassed.
Link: https://lore.kernel.org/linux-trace-kernel/20230414071729.57312-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 2d5c3caff32d..58be5b409f72 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2054,10 +2054,11 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer) struct list_head *head_page, *prev_page, *r; struct list_head *last_page, *first_page; struct list_head *head_page_with_bit; + struct buffer_page *hpage = rb_set_head_page(cpu_buffer); - head_page = &rb_set_head_page(cpu_buffer)->list; - if (!head_page) + if (!hpage) break; + head_page = &hpage->list; prev_page = head_page->prev; first_page = pages->next; |