bpf: Fix mmap_lock deadlock on arena lock failure
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix mmap_lock deadlock on arena lock failure Reported by the Sashiko AI review. arena_vm_fault() returns VM_FAULT_RETRY when it can't take arena->spinlock, but it never took mmap_lock. The fault path assumes a VM_FAULT_RETRY handler already dropped mmap_lock and re-takes it on the retry, so mmap_lock gets taken twice and can deadlock: do_user_addr_fault() { fault = handle_mm_fault(...); // calls arena_vm_fault() if (fault & VM_FAULT_RETRY) goto retry; // re-locks mmap_lock mmap_read_unlock(mm); } Return VM_FAULT_SIGBUS instead, for two reasons: 1. We could keep VM_FAULT_RETRY, but then we'd have to drop the fault lock first and cap the retry ourselves, the way __folio_lock_or_retry() does. 2. A failed raw_res_spin_lock_irqsave() already means a possible deadlock was detected, so retrying just hits the same lock again. So returning VM_FAULT_RETRY here is overkill.
CVE-2026-90342
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-90342
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "b8467290edab4bafae352bf3f317055669a1a458",
"lessThan": "af8087f16714f7620c4db3e732baaa1b2337948f",
"versionType": "git"
},
{
"status": "affected",
"version": "b8467290edab4bafae352bf3f317055669a1a458",
"lessThan": "0b10b945479c954393d62ee3229d2f224a4ca91c",
"versionType": "git"
}
],
"programFiles": [
"kernel/bpf/arena.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "7.0"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "7.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"kernel/bpf/arena.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-90342
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #36683 · Revision 1
- Added to Heist Feed
- Publisher date