riscv: vdso: fix NULL deference in vdso_join_timens() when vfork
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.
- Published
- Dec 9, 2025
- Updated
- Jun 17, 2026
- EPSS
- 0.2% · 13th percentile
- CWE
- —
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Report tools
Action score
0
Monitor
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
Affected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 5.19affected
- 3092eb45637573c5e435fbf5eaf9516316e5f9c6 and later · before df30c4feba51beeb138f3518c2421abc8cbda3c1affected · git
- 3092eb45637573c5e435fbf5eaf9516316e5f9c6 and later · before f2419a6fbb4caf8cf3fe0ac7e4cf2e28127d04b4affected · git
- 3092eb45637573c5e435fbf5eaf9516316e5f9c6 and later · before a8616d2dc193b6becc36b5f3cfeaa9ac7a5762f9affected · git
- before 5.19not affected · semver
- 5.19.17 and later · up to and including 5.19.*not affected · semver
- 6.0.3 and later · up to and including 6.0.*not affected · semver
- 6.1 and laternot affected · original_commit_for_fix
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.0.3-1 | 6.0.3-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
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- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
- CVE-2026-74309vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler40Plan
- CVE-2026-74280crypto: marvell/octeontx - fix DMA cleanup using wrong loop index40Plan
- CVE-2026-74279crypto: cavium/cpt - fix DMA cleanup using wrong loop index40Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | a8616d2dc193b6becc36b5f3cfeaa9ac7a5762f9 | Vendor (CNA) |
| Linux Linux | df30c4feba51beeb138f3518c2421abc8cbda3c1 | Vendor (CNA) |
| Linux Linux | f2419a6fbb4caf8cf3fe0ac7e4cf2e28127d04b4 | Vendor (CNA) |
| debian:linux | 6.0.3-1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
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No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
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No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
—
Attack context
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Noroxi analysis
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We use this product, ask for helpChange log
- Fix✗ → ✓
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References
- git.kernel.org/stable/c/a8616d2dc193b6becc36b5f3cfeaa9ac7a5762f9
- git.kernel.org/stable/c/df30c4feba51beeb138f3518c2421abc8cbda3c1
- git.kernel.org/stable/c/f2419a6fbb4caf8cf3fe0ac7e4cf2e28127d04b4
Vendor advisories and official records. Exploit/PoC links are deliberately left out.