Summaryinfo

A vulnerability was found in Linux Kernel up to 5.19.16/6.0.2. It has been classified as critical. This affects the function vdso_join_timens of the file tools/testing/selftests/timens/vfork_exec.c of the component riscv. Performing a manipulation results in null pointer dereference. This vulnerability is identified as CVE-2022-50674. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.19.16/6.0.2. It has been classified as critical. This affects the function vdso_join_timens of the file tools/testing/selftests/timens/vfork_exec.c of the component riscv. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: riscv: vdso: fix NULL deference in vdso_join_timens() when vfork Testing tools/testing/selftests/timens/vfork_exec.c got below kernel log: [ 6.838454] Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000020 [ 6.842255] Oops [#1] [ 6.842871] Modules linked in: [ 6.844249] CPU: 1 PID: 64 Comm: vfork_exec Not tainted 6.0.0-rc3-rt15+ #8 [ 6.845861] Hardware name: riscv-virtio,qemu (DT) [ 6.848009] epc : vdso_join_timens+0xd2/0x110 [ 6.850097] ra : vdso_join_timens+0xd2/0x110 [ 6.851164] epc : ffffffff8000635c ra : ffffffff8000635c sp : ff6000000181fbf0 [ 6.852562] gp : ffffffff80cff648 tp : ff60000000fdb700 t0 : 3030303030303030 [ 6.853852] t1 : 0000000000000030 t2 : 3030303030303030 s0 : ff6000000181fc40 [ 6.854984] s1 : ff60000001e6c000 a0 : 0000000000000010 a1 : ffffffff8005654c [ 6.856221] a2 : 00000000ffffefff a3 : 0000000000000000 a4 : 0000000000000000 [ 6.858114] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038 [ 6.859484] s2 : ff60000001e6c068 s3 : ff6000000108abb0 s4 : 0000000000000000 [ 6.860751] s5 : 0000000000001000 s6 : ffffffff8089dc40 s7 : ffffffff8089dc38 [ 6.862029] s8 : ffffffff8089dc30 s9 : ff60000000fdbe38 s10: 000000000000005e [ 6.863304] s11: ffffffff80cc3510 t3 : ffffffff80d1112f t4 : ffffffff80d1112f [ 6.864565] t5 : ffffffff80d11130 t6 : ff6000000181fa00 [ 6.865561] status: 0000000000000120 badaddr: 0000000000000020 cause: 000000000000000d [ 6.868046] [<ffffffff8008dc94>] timens_commit+0x38/0x11a [ 6.869089] [<ffffffff8008dde8>] timens_on_fork+0x72/0xb4 [ 6.870055] [<ffffffff80190096>] begin_new_exec+0x3c6/0x9f0 [ 6.871231] [<ffffffff801d826c>] load_elf_binary+0x628/0x1214 [ 6.872304] [<ffffffff8018ee7a>] bprm_execve+0x1f2/0x4e4 [ 6.873243] [<ffffffff8018f90c>] do_execveat_common+0x16e/0x1ee [ 6.874258] [<ffffffff8018f9c8>] sys_execve+0x3c/0x48 [ 6.875162] [<ffffffff80003556>] ret_from_syscall+0x0/0x2 [ 6.877484] ---[ end trace 0000000000000000 ]--- This is because the mm->context.vdso_info is NULL in vfork case. From another side, mm->context.vdso_info either points to vdso info for RV64 or vdso info for compat, there's no need to bloat riscv's mm_context_t, we can handle the difference when setup the additional page for vdso.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2022-50674 since 12/09/2025. The exploitability is told to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 278329 (Linux Distros Unpatched Vulnerability : CVE-2022-50674), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.19.17 or 6.0.3 eliminates this vulnerability. Applying the patch df30c4feba51beeb138f3518c2421abc8cbda3c1/f2419a6fbb4caf8cf3fe0ac7e4cf2e28127d04b4/a8616d2dc193b6becc36b5f3cfeaa9ac7a5762f9 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 databases at Tenable (278329) and CERT Bund (WID-SEC-2025-2765). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.19.0
• 5.19.1
• 5.19.2
• 5.19.3
• 5.19.4
• 5.19.5
• 5.19.6
• 5.19.7
• 5.19.8
• 5.19.9
• 5.19.10
• 5.19.11
• 5.19.12
• 5.19.13
• 5.19.14
• 5.19.15
• 5.19.16
• 6.0.0
• 6.0.1
• 6.0.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Discussion