powerpc/syscall: Fix syscall skip handling for seccomp and ptrace
In the Linux kernel, the following vulnerability has been resolved: powerpc/syscall: Fix syscall skip handling for seccomp and ptrace After enabling GENERIC_ENTRY on PowerPC, syscall_enter_from_user_mode() returns -1 as a sentinel to signal that seccomp or ptrace has intercepted the syscall and already set a return value via syscall_set_return_value(). system_call_exception() was not handling this sentinel, and since -1UL is >= NR_syscalls, the code fell into the out-of-range path and returned -ENOSYS, overwriting the errno already placed in regs->gpr[3]. The naive fix of checking r0 == -1L before the NR_syscalls bounds check is ambiguous: a user legitimately calling syscall(-1) also produces r0 == -1L, and a tracer intercepting such a call would have its injected return value silently discarded. Fix this by introducing a thread flag that is set whenever syscall_set_return_value() explicitly updates the return value. In system_call_exception(), check and clear this flag before dispatching the syscall, and return the preset value directly when it is present. This ensures that an explicitly supplied return value always suppresses syscall execution, regardless of the syscall number. This handles all seccomp actions correctly: - SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE (no tracer), SECCOMP_RET_USER_NOTIF: all call syscall_set_return_value(), flag is set, injected value returned. - SECCOMP_RET_TRAP, SECCOMP_RET_KILL: call syscall_rollback() and deliver a signal; flag is not set, but t
CVE-2026-90339
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-2026-90339
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": "bee25f97ad24641df55cb3887eb5bfcb2b9d8fbc",
"lessThan": "19b54740e2e1102c7d48553d9e0347c1f6af22b0",
"versionType": "git"
},
{
"status": "affected",
"version": "bee25f97ad24641df55cb3887eb5bfcb2b9d8fbc",
"lessThan": "69cb2be898be6d5826cacd1a628f6945a24480b6",
"versionType": "git"
}
],
"programFiles": [
"arch/powerpc/include/asm/syscall.h",
"arch/powerpc/include/asm/thread_info.h",
"arch/powerpc/kernel/syscall.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "7.2"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "7.2",
"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": [
"arch/powerpc/include/asm/syscall.h",
"arch/powerpc/include/asm/thread_info.h",
"arch/powerpc/kernel/syscall.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-90339
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #36679 · Revision 1
- Added to Heist Feed
- Publisher date