CVE-2023-53441

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> bpf: cpumap: Fix memory leak in cpu_map_update_elem<br /> <br /> Syzkaller reported a memory leak as follows:<br /> <br /> BUG: memory leak<br /> unreferenced object 0xff110001198ef748 (size 192):<br /> comm "syz-executor.3", pid 17672, jiffies 4298118891 (age 9.906s)<br /> hex dump (first 32 bytes):<br /> 00 00 00 00 4a 19 00 00 80 ad e3 e4 fe ff c0 00 ....J...........<br /> 00 b2 d3 0c 01 00 11 ff 28 f5 8e 19 01 00 11 ff ........(.......<br /> backtrace:<br /> [] __cpu_map_entry_alloc+0xf7/0xb00<br /> [] cpu_map_update_elem+0x2fe/0x3d0<br /> [] bpf_map_update_value.isra.0+0x2bd/0x520<br /> [] map_update_elem+0x4cb/0x720<br /> [] __se_sys_bpf+0x8c3/0xb90<br /> [] do_syscall_64+0x30/0x40<br /> [] entry_SYSCALL_64_after_hwframe+0x61/0xc6<br /> <br /> BUG: memory leak<br /> unreferenced object 0xff110001198ef528 (size 192):<br /> comm "syz-executor.3", pid 17672, jiffies 4298118891 (age 9.906s)<br /> hex dump (first 32 bytes):<br /> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................<br /> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................<br /> backtrace:<br /> [] __cpu_map_entry_alloc+0x260/0xb00<br /> [] cpu_map_update_elem+0x2fe/0x3d0<br /> [] bpf_map_update_value.isra.0+0x2bd/0x520<br /> [] map_update_elem+0x4cb/0x720<br /> [] __se_sys_bpf+0x8c3/0xb90<br /> [] do_syscall_64+0x30/0x40<br /> [] entry_SYSCALL_64_after_hwframe+0x61/0xc6<br /> <br /> BUG: memory leak<br /> unreferenced object 0xff1100010fd93d68 (size 8):<br /> comm "syz-executor.3", pid 17672, jiffies 4298118891 (age 9.906s)<br /> hex dump (first 8 bytes):<br /> 00 00 00 00 00 00 00 00 ........<br /> backtrace:<br /> [] kvmalloc_node+0x11e/0x170<br /> [] __cpu_map_entry_alloc+0x2f0/0xb00<br /> [] cpu_map_update_elem+0x2fe/0x3d0<br /> [] bpf_map_update_value.isra.0+0x2bd/0x520<br /> [] map_update_elem+0x4cb/0x720<br /> [] __se_sys_bpf+0x8c3/0xb90<br /> [] do_syscall_64+0x30/0x40<br /> [] entry_SYSCALL_64_after_hwframe+0x61/0xc6<br /> <br /> In the cpu_map_update_elem flow, when kthread_stop is called before<br /> calling the threadfn of rcpu-&gt;kthread, since the KTHREAD_SHOULD_STOP bit<br /> of kthread has been set by kthread_stop, the threadfn of rcpu-&gt;kthread<br /> will never be executed, and rcpu-&gt;refcnt will never be 0, which will<br /> lead to the allocated rcpu, rcpu-&gt;queue and rcpu-&gt;queue-&gt;queue cannot be<br /> released.<br /> <br /> Calling kthread_stop before executing kthread&amp;#39;s threadfn will return<br /> -EINTR. We can complete the release of memory resources in this state.