{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-46250", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.107Z", "datePublished": "2026-06-03T15:49:46.390Z", "dateUpdated": "2026-08-05T12:30:44.867Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:30:44.867Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nMIPS: Work around LLVM bug when gp is used as global register variable\n\nOn MIPS, __current_thread_info is defined as global register variable\nlocating in $gp, and is simply assigned with new address during kernel\nrelocation.\n\nThis however is broken with LLVM, which always restores $gp if it finds\n$gp is clobbered in any form, including when intentionally through a\nglobal register variable. This is against GCC's documentation[1], which\nrequires a callee-saved register used as global register variable not to\nbe restored if it's clobbered.\n\nAs a result, $gp will continue to point to the unrelocated kernel after\nthe epilog of relocate_kernel(), leading to an early crash in init_idle,\n\n[ 0.000000] CPU 0 Unable to handle kernel paging request at virtual address 0000000000000000, epc == ffffffff81afada8, ra == ffffffff81afad90\n[ 0.000000] Oops[#1]:\n[ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Tainted: G W 6.19.0-rc5-00262-gd3eeb99bbc99-dirty #188 VOLUNTARY\n[ 0.000000] Tainted: [W]=WARN\n[ 0.000000] Hardware name: loongson,loongson64v-4core-virtio\n[ 0.000000] $ 0 : 0000000000000000 0000000000000000 0000000000000001 0000000000000000\n[ 0.000000] $ 4 : ffffffff80b80ec0 ffffffff80b53d48 0000000000000000 00000000000f4240\n[ 0.000000] $ 8 : 0000000000000100 ffffffff81d82f80 ffffffff81d82f80 0000000000000001\n[ 0.000000] $12 : 0000000000000000 ffffffff81776f58 00000000000005da 0000000000000002\n[ 0.000000] $16 : ffffffff80b80e40 0000000000000000 ffffffff80b81614 9800000005dfbe80\n[ 0.000000] $20 : 00000000540000e0 ffffffff81980000 0000000000000000 ffffffff80f81c80\n[ 0.000000] $24 : 0000000000000a26 ffffffff8114fb90\n[ 0.000000] $28 : ffffffff80b50000 ffffffff80b53d40 0000000000000000 ffffffff81afad90\n[ 0.000000] Hi : 0000000000000000\n[ 0.000000] Lo : 0000000000000000\n[ 0.000000] epc : ffffffff81afada8 init_idle+0x130/0x270\n[ 0.000000] ra : ffffffff81afad90 init_idle+0x118/0x270\n[ 0.000000] Status: 540000e2\tKX SX UX KERNEL EXL\n[ 0.000000] Cause : 00000008 (ExcCode 02)\n[ 0.000000] BadVA : 0000000000000000\n[ 0.000000] PrId : 00006305 (ICT Loongson-3)\n[ 0.000000] Process swapper (pid: 0, threadinfo=(____ptrval____), task=(____ptrval____), tls=0000000000000000)\n[ 0.000000] Stack : 9800000005dfbf00 ffffffff8178e950 0000000000000000 0000000000000000\n[ 0.000000] 0000000000000000 ffffffff81970000 000000000000003f ffffffff810a6528\n[ 0.000000] 0000000000000001 9800000005dfbe80 9800000005dfbf00 ffffffff81980000\n[ 0.000000] ffffffff810a6450 ffffffff81afb6c0 0000000000000000 ffffffff810a2258\n[ 0.000000] ffffffff81d82ec8 ffffffff8198d010 ffffffff81b67e80 ffffffff8197dd98\n[ 0.000000] ffffffff81d81c80 ffffffff81930000 0000000000000040 0000000000000000\n[ 0.000000] 0000000000000000 0000000000000000 0000000000000000 0000000000000000\n[ 0.000000] 0000000000000000 000000000000009e ffffffff9fc01000 0000000000000000\n[ 0.000000] 0000000000000000 0000000000000000 0000000000000000 0000000000000000\n[ 0.000000] 0000000000000000 ffffffff81ae86dc ffffffff81b3c741 0000000000000002\n[ 0.000000] ...\n[ 0.000000] Call Trace:\n[ 0.000000] [] init_idle+0x130/0x270\n[ 0.000000] [] sched_init+0x5c8/0x6c0\n[ 0.000000] [] start_kernel+0x27c/0x7a8\n\nThis bug has been reported to LLVM[2] and affects version from (at\nleast) 18 to 21. Let's work around this by using inline assembly to\nassign $gp before a fix is widely available." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H", "baseScore": 7.3, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable code runs only during early boot in `relocate_kernel()` (`arch/mips/kernel/head.S` → `arch/mips/kernel/relocate.c`), before any network stack or syscall interface exists; the only way to reach it is to boot or reboot the MIPS system locally.\nAC:L - When the kernel is built with LLVM/Clang, `CONFIG_RELOCATABLE`, and KASLR relocation (`offset != 0`), LLVM deterministically restores `$gp` in the `relocate_kernel()` epilog, causing a reliable crash in `init_idle()` on every affected boot without races or attacker-uncontrollable timing.\nPR:N - Execution occurs in the pre-authentication boot path (PID 0 swapper during `start_kernel()` → `sched_init()` → `init_idle()`), before any user login or privilege checks; no attacker credentials are required at the time the bug triggers.\nUI:N - No victim user action is required beyond normal system power-on or reboot; the fault occurs automatically during kernel initialization on affected builds.\nS:U - Impact is confined to kernel boot failure on the same machine; there is no crossing of security boundaries such as VM escape, sandbox escape, or IOMMU bypass.\nC:L - The stale `$gp`/`__current_thread_info` causes `current` to resolve from the unrelocated `init_thread_union`, leading to dereferences of invalid kernel memory and limited kernel-address information exposure in the oops before the paging fault at address 0.\nI:L - Before the fatal fault, `init_idle()` performs writes through the mis-resolved `current` pointer (e.g., task state and scheduler fields), enabling limited unintended modification of kernel structures even though the immediate outcome is a crash rather than controlled code execution.\nA:H - The bug produces a kernel oops during early boot in `init_idle()` with \"Unable to handle kernel paging request at virtual address 0000000000000000\", preventing the system from completing initialization and rendering it unavailable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/mips/kernel/relocate.c" ], "versions": [ { "version": "279b991b24d2439fbe9d2f093988b9c8aed2603d", "lessThan": "05bff9b0ae095b2420cfebb4a96759a09334bec6", "status": "affected", "versionType": "git" }, { "version": "279b991b24d2439fbe9d2f093988b9c8aed2603d", "lessThan": "1fe3b402b1e97a1718df3be0a1d3eee20133e735", "status": "affected", "versionType": "git" }, { "version": "279b991b24d2439fbe9d2f093988b9c8aed2603d", "lessThan": "4dc65b40fb80c2020efbf139b9a38d30f9a37b92", "status": "affected", "versionType": "git" }, { "version": "279b991b24d2439fbe9d2f093988b9c8aed2603d", "lessThan": "c0155dee51b9f5f48aaf5c71cae005eb0e36521f", "status": "affected", "versionType": "git" }, { "version": "279b991b24d2439fbe9d2f093988b9c8aed2603d", "lessThan": "e3a6498a63394218561065a9a7a597a204f52f6a", "status": "affected", "versionType": "git" }, { "version": "279b991b24d2439fbe9d2f093988b9c8aed2603d", "lessThan": "561834f6d6f52b8a1791331e94b2aac753491d2a", "status": "affected", "versionType": "git" }, { "version": "279b991b24d2439fbe9d2f093988b9c8aed2603d", "lessThan": "9bc3b0ae5203aba650297fdf3e1e774125e423f2", "status": "affected", "versionType": "git" }, { "version": "279b991b24d2439fbe9d2f093988b9c8aed2603d", "lessThan": "30bfc2d6a1132a89a5f1c3b96c59cf3e4d076ea3", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/mips/kernel/relocate.c" ], "versions": [ { "version": "4.7", "status": "affected" }, { "version": "0", "lessThan": "4.7", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.252", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.202", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.165", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.128", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.75", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.14", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.4", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "5.10.252" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "5.15.202" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "6.1.165" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "6.6.128" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "6.12.75" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "6.18.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "6.19.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/05bff9b0ae095b2420cfebb4a96759a09334bec6" }, { "url": "https://git.kernel.org/stable/c/1fe3b402b1e97a1718df3be0a1d3eee20133e735" }, { "url": "https://git.kernel.org/stable/c/4dc65b40fb80c2020efbf139b9a38d30f9a37b92" }, { "url": "https://git.kernel.org/stable/c/c0155dee51b9f5f48aaf5c71cae005eb0e36521f" }, { "url": "https://git.kernel.org/stable/c/e3a6498a63394218561065a9a7a597a204f52f6a" }, { "url": "https://git.kernel.org/stable/c/561834f6d6f52b8a1791331e94b2aac753491d2a" }, { "url": "https://git.kernel.org/stable/c/9bc3b0ae5203aba650297fdf3e1e774125e423f2" }, { "url": "https://git.kernel.org/stable/c/30bfc2d6a1132a89a5f1c3b96c59cf3e4d076ea3" } ], "title": "MIPS: Work around LLVM bug when gp is used as global register variable", "x_generator": { "engine": "bippy-1.2.0" } } } }