Summary
In the Linux kernel, the following vulnerability has been resolved: net/handshake: fix null-ptr...
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)
Impact
The application dereferences a null pointer, causing a crash. Typical impact: denial of service via crash.
CVE-2023-53686 has a CVSS score of 5.5 (Medium). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2023-53686? CVE-2023-53686 is a medium-severity null pointer dereference vulnerability. No fixed version is listed yet. The application dereferences a null pointer, causing a crash.
- How severe is CVE-2023-53686? CVE-2023-53686 has a CVSS score of 5.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Is there a fix for CVE-2023-53686? No fixed version is listed for CVE-2023-53686 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2023-53686 exploitable, and should I be worried? Whether CVE-2023-53686 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-53686 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.