CVE-2023-52995 riscv/kprobe: Fix instruction simulation of JALR

Medium 5.5 Published 27 Mar 2025 Updated 11 May 2026

A flaw in RISC-V kprobe instruction simulation causes a kernel crash when specific instructions are probed, leading to denial of service.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2023-52995?

CVE-2023-52995 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

riscv/kprobe: Fix instruction simulation of JALR

Set kprobe at 'jalr 1140(ra)' of vfs_write results in the following crash:

[ 32.092235] Unable to handle kernel access to user memory without uaccess routines at virtual address 00aaaaaad77b1170 [ 32.093115] Oops [#1] [ 32.093251] Modules linked in: [ 32.093626] CPU: 0 PID: 135 Comm: ftracetest Not tainted 6.2.0-rc2-00013-gb0aa5e5df0cb-dirty #16 [ 32.093985] Hardware name: riscv-virtio,qemu (DT) [ 32.094280] epc : ksys_read+0x88/0xd6 [ 32.094855] ra : ksys_read+0xc0/0xd6 [ 32.095016] epc : ffffffff801cda80 ra : ffffffff801cdab8 sp : ff20000000d7bdc0 [ 32.095227] gp : ffffffff80f14000 tp : ff60000080f9cb40 t0 : ffffffff80f13e80 [ 32.095500] t1 : ffffffff8000c29c t2 : ffffffff800dbc54 s0 : ff20000000d7be60 [ 32.095716] s1 : 0000000000000000 a0 : ffffffff805a64ae a1 : ffffffff80a83708 [ 32.095921] a2 : ffffffff80f160a0 a3 : 0000000000000000 a4 : f229b0afdb165300 [ 32.096171] a5 : f229b0afdb165300 a6 : ffffffff80eeebd0 a7 : 00000000000003ff [ 32.096411] s2 : ff6000007ff76800 s3 : fffffffffffffff7 s4 : 00aaaaaad77b1170 [ 32.096638] s5 : ffffffff80f160a0 s6 : ff6000007ff76800 s7 : 0000000000000030 [ 32.096865] s8 : 00ffffffc3d97be0 s9 : 0000000000000007 s10: 00aaaaaad77c9410 [ 32.097092] s11: 0000000000000000 t3 : ffffffff80f13e48 t4 : ffffffff8000c29c [ 32.097317] t5 : ffffffff8000c29c t6 : ffffffff800dbc54 [ 32.097505] status: 0000000200000120 badaddr: 00aaaaaad77b1170 cause: 000000000000000d [ 32.098011] [<ffffffff801cdb72>] ksys_write+0x6c/0xd6 [ 32.098222] [<ffffffff801cdc06>] sys_write+0x2a/0x38 [ 32.098405] [<ffffffff80003c76>] ret_from_syscall+0x0/0x2

Since the rs1 and rd might be the same one, such as 'jalr 1140(ra)', hence it requires obtaining the target address from rs1 followed by updating rd.

[Palmer: Pick Guo's cleanup]

Which versions are affected by CVE-2023-52995?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2023-52995?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2023-52995 being exploited?

There is no known exploitation of CVE-2023-52995 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2023-52995, DEBIAN-CVE-2023-52995, GHSA-76g9-mx4c-qm64, UBUNTU-CVE-2023-52995.