CVE-2023-53686

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net/handshake: fix null-ptr-deref in handshake_nl_done_doit()<br /> <br /> We should not call trace_handshake_cmd_done_err() if socket lookup has failed.<br /> <br /> Also we should call trace_handshake_cmd_done_err() before releasing the file,<br /> otherwise dereferencing sock-&gt;sk can return garbage.<br /> <br /> This also reverts 7afc6d0a107f ("net/handshake: Fix uninitialized local variable")<br /> <br /> Unable to handle kernel paging request at virtual address dfff800000000003<br /> KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]<br /> Mem abort info:<br /> ESR = 0x0000000096000005<br /> EC = 0x25: DABT (current EL), IL = 32 bits<br /> SET = 0, FnV = 0<br /> EA = 0, S1PTW = 0<br /> FSC = 0x05: level 1 translation fault<br /> Data abort info:<br /> ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000<br /> CM = 0, WnR = 0, TnD = 0, TagAccess = 0<br /> GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0<br /> [dfff800000000003] address between user and kernel address ranges<br /> Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP<br /> Modules linked in:<br /> CPU: 1 PID: 5986 Comm: syz-executor292 Not tainted 6.5.0-rc7-syzkaller-gfe4469582053 #0<br /> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023<br /> pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)<br /> pc : handshake_nl_done_doit+0x198/0x9c8 net/handshake/netlink.c:193<br /> lr : handshake_nl_done_doit+0x180/0x9c8<br /> sp : ffff800096e37180<br /> x29: ffff800096e37200 x28: 1ffff00012dc6e34 x27: dfff800000000000<br /> x26: ffff800096e373d0 x25: 0000000000000000 x24: 00000000ffffffa8<br /> x23: ffff800096e373f0 x22: 1ffff00012dc6e38 x21: 0000000000000000<br /> x20: ffff800096e371c0 x19: 0000000000000018 x18: 0000000000000000<br /> x17: 0000000000000000 x16: ffff800080516cc4 x15: 0000000000000001<br /> x14: 1fffe0001b14aa3b x13: 0000000000000000 x12: 0000000000000000<br /> x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000003<br /> x8 : 0000000000000003 x7 : ffff800080afe47c x6 : 0000000000000000<br /> x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080a88078<br /> x2 : 0000000000000001 x1 : 00000000ffffffa8 x0 : 0000000000000000<br /> Call trace:<br /> handshake_nl_done_doit+0x198/0x9c8 net/handshake/netlink.c:193<br /> genl_family_rcv_msg_doit net/netlink/genetlink.c:970 [inline]<br /> genl_family_rcv_msg net/netlink/genetlink.c:1050 [inline]<br /> genl_rcv_msg+0x96c/0xc50 net/netlink/genetlink.c:1067<br /> netlink_rcv_skb+0x214/0x3c4 net/netlink/af_netlink.c:2549<br /> genl_rcv+0x38/0x50 net/netlink/genetlink.c:1078<br /> netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]<br /> netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1365<br /> netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1914<br /> sock_sendmsg_nosec net/socket.c:725 [inline]<br /> sock_sendmsg net/socket.c:748 [inline]<br /> ____sys_sendmsg+0x56c/0x840 net/socket.c:2494<br /> ___sys_sendmsg net/socket.c:2548 [inline]<br /> __sys_sendmsg+0x26c/0x33c net/socket.c:2577<br /> __do_sys_sendmsg net/socket.c:2586 [inline]<br /> __se_sys_sendmsg net/socket.c:2584 [inline]<br /> __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2584<br /> __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]<br /> invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51<br /> el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136<br /> do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155<br /> el0_svc+0x58/0x16c arch/arm64/kernel/entry-common.c:678<br /> el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696<br /> el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591<br /> Code: 12800108 b90043e8 910062b3 d343fe68 (387b6908)