In the Linux kernel, the following vulnerability has been resolved:
parisc: Avoid crash due to unaligned access in unwinder
Guenter Roeck reported this kernel crash on his emulated B160L machine:
Starting network: udhcpc: started, v1.36.1
Backtrace:
[<104320d4>] unwind_once+0x1c/0x5c
[<10434a00>] walk_stackframe.isra.0+0x74/0xb8
[<10434a6c>] arch_stack_walk+0x28/0x38
[<104e5efc>] stack_trace_save+0x48/0x5c
[<105d1bdc>] set_track_prepare+0x44/0x6c
[<105d9c80>] ___slab_alloc+0xfc4/0x1024
[<105d9d38>] __slab_alloc.isra.0+0x58/0x90
[<105dc80c>] kmem_cache_alloc_noprof+0x2ac/0x4a0
[<105b8e54>] __anon_vma_prepare+0x60/0x280
[<105a823c>] __vmf_anon_prepare+0x68/0x94
[<105a8b34>] do_wp_page+0x8cc/0xf10
[<105aad88>] handle_mm_fault+0x6c0/0xf08
[<10425568>] do_page_fault+0x110/0x440
[<10427938>] handle_interruption+0x184/0x748
[<11178398>] schedule+0x4c/0x190
BUG: spinlock recursion on CPU#0, ifconfig/2420
lock: terminate_lock.2+0x0/0x1c, .magic: dead4ead, .owner: ifconfig/2420, .owner_cpu: 0
While creating the stack trace, the unwinder uses the stack pointer to guess
the previous frame to read the previous stack pointer from memory. The crash
happens, because the unwinder tries to read from unaligned memory and as such
triggers the unalignment trap handler which then leads to the spinlock
recursion and finally to a deadlock.
Fix it by checking the alignment before accessing the memory.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
- EG Severity
- Not assessed: no CVSS publishedA missing CVSS is not a severity of zero.
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- No SSVC decision: EchelonGraph has not assessed this CVECISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the BOD 26-04 block below.
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it