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authorDaniil Tatianin <d-tatianin@yandex-team.ru>2022-11-14 15:31:29 +0100
committerSteven Rostedt (Google) <rostedt@goodmis.org>2022-11-17 23:10:40 +0100
commit56f4ca0a79a9f1af98f26c54b9b89ba1f9bcc6bd (patch)
treeb72c17d1e457578b5650cef39bf861e261608202 /kernel/trace/ring_buffer.c
parentftrace: Optimize the allocation for mcount entries (diff)
downloadlinux-56f4ca0a79a9f1af98f26c54b9b89ba1f9bcc6bd.tar.xz
linux-56f4ca0a79a9f1af98f26c54b9b89ba1f9bcc6bd.zip
ring_buffer: Do not deactivate non-existant pages
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>
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index a19369c4d8df..b21bf14bae9b 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1802,9 +1802,9 @@ 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);