In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
tracing: Fix use-after-free in trace_pipe read on sub-buffer order change<\/p>\n
Writing to buffer_subbuf_size_kb calls ring_buffer_subbuf_order_set(),
\nwhich frees every sub-buffer of the ring buffer, including the reader
\npage, and replaces them with newly allocated ones.<\/p>\n
Readers of trace_pipe hold pointers into those pages. ring_buffer_peek()
\nlooks up an event under cpu_buffer->reader_lock but returns the event
\npointer after dropping the lock, and peek_next_entry() then calls
\nring_buffer_event_length() and ring_buffer_event_data() on it. If the
\nsub-buffer order is changed in that window, the reader dereferences
\nfreed memory:<\/p>\n
BUG: KASAN: use-after-free in ring_buffer_peek+0x3e0\/0x430
\n Read of size 1 at addr ffff88802a4cf010 by task syz-executor989\/6002<\/p>\n
Freed by:
\n free_buffer_page kernel\/trace\/ring_buffer.c:398 [inline]
\n ring_buffer_subbuf_order_set+0x1325\/0x18e0 kernel\/trace\/ring_buffer.c:7444
\n buffer_subbuf_size_write+0x182\/0x280 kernel\/trace\/trace.c:8221<\/p>\n
Take trace_access_lock(RING_BUFFER_ALL_CPUS) around the order change.
\nThis is the lock trace_pipe readers already hold across their entire
\npeek-and-print loop, so the swap can no longer race with a reader that
\nis dereferencing a peeked event.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
tracing: Fix use-after-free in trace_pipe read on sub-buffer order change<\/p>\n
Writing to buffer_subbuf_size_kb calls ring_buffer_subbu<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21669","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21669","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21669"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21669"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21669"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}