diff options
author | Daniil Tatianin <d-tatianin@yandex-team.ru> | 2022-11-14 17:31:29 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-25 17:45:48 +0100 |
commit | 5fdebbeca5dbc2cde6cca9562fc02841e1155c9d (patch) | |
tree | 25caeb8f6687567955f8390c4824013562129fe9 | |
parent | 6a14828caddad0d989495a72af678adf60992704 (diff) |
ring_buffer: Do not deactivate non-existant pages
commit 56f4ca0a79a9f1af98f26c54b9b89ba1f9bcc6bd upstream.
rb_head_page_deactivate() expects cpu_buffer to contain a valid list of
->pages, so verify that the list is actually present before calling it.
Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.
Link: https://lkml.kernel.org/r/20221114143129.3534443-1-d-tatianin@yandex-team.ru
Cc: stable@vger.kernel.org
Fixes: 77ae365eca895 ("ring-buffer: make lockless")
Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | kernel/trace/ring_buffer.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index a12e27815555..1e9de3d49701 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1635,9 +1635,9 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer) free_buffer_page(cpu_buffer->reader_page); - rb_head_page_deactivate(cpu_buffer); - if (head) { + rb_head_page_deactivate(cpu_buffer); + list_for_each_entry_safe(bpage, tmp, head, list) { list_del_init(&bpage->list); free_buffer_page(bpage); |