Linux Kernel up to 6.5.3 handshake_nl_done_doit uninitialized pointer

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.5.3. It has been classified as critical. The impacted element is the function handshake_nl_done_doit. The manipulation leads to uninitialized pointer. This vulnerability is documented as CVE-2023-53686. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.5.3. This issue affects the function handshake_nl_done_doit. The manipulation with an unknown input leads to a uninitialized pointer vulnerability. Using CWE to declare the problem leads to CWE-824. The product accesses or uses a pointer that has not been initialized. Impacted is availability. The summary by CVE is:

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

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2023-53686 since 10/07/2025. The exploitation is known to be difficult. Technical details are known, but no exploit is available.

Upgrading to version 6.5.4 eliminates this vulnerability. Applying the patch 93d69f18edcca282351394c5870bec24cc99d745/82ba0ff7bf0483d962e592017bef659ae022d754 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-2229). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Amazon Linux 2
• Red Hat Enterprise Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux
• Open Source Linux Kernel
• IBM QRadar SIEM
• Dell NetWorker

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.5.0
• 6.5.1
• 6.5.2
• 6.5.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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