CVE-2023-53075

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ftrace: Fix invalid address access in lookup_rec() when index is 0<br /> <br /> KASAN reported follow problem:<br /> <br /> BUG: KASAN: use-after-free in lookup_rec<br /> Read of size 8 at addr ffff000199270ff0 by task modprobe<br /> CPU: 2 Comm: modprobe<br /> Call trace:<br /> kasan_report<br /> __asan_load8<br /> lookup_rec<br /> ftrace_location<br /> arch_check_ftrace_location<br /> check_kprobe_address_safe<br /> register_kprobe<br /> <br /> When checking pg-&gt;records[pg-&gt;index - 1].ip in lookup_rec(), it can get a<br /> pg which is newly added to ftrace_pages_start in ftrace_process_locs().<br /> Before the first pg-&gt;index++, index is 0 and accessing pg-&gt;records[-1].ip<br /> will cause this problem.<br /> <br /> Don&amp;#39;t check the ip when pg-&gt;index is 0.