ghsa-gxj3-8g3m-8hpw
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
x86/Kconfig: make CFI_AUTO_DEFAULT depend on !RUST or Rust >= 1.88
Calling core::fmt::write() from rust code while FineIBT is enabled results in a kernel panic:
[ 4614.199779] kernel BUG at arch/x86/kernel/cet.c:132! [ 4614.205343] Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 4614.211781] CPU: 2 UID: 0 PID: 6057 Comm: dmabuf_dump Tainted: G U O 6.12.17-android16-0-g6ab38c534a43 #1 9da040f27673ec3945e23b998a0f8bd64c846599 [ 4614.227832] Tainted: [U]=USER, [O]=OOT_MODULE [ 4614.241247] RIP: 0010:do_kernel_cp_fault+0xea/0xf0 ... [ 4614.398144] RIP: 0010:_RNvXs5_NtNtNtCs3o2tGsuHyou_4core3fmt3num3impyNtB9_7Display3fmt+0x0/0x20 [ 4614.407792] Code: 48 f7 df 48 0f 48 f9 48 89 f2 89 c6 5d e9 18 fd ff ff 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 41 81 ea 14 61 af 2c 74 03 0f 0b 90 <66> 0f 1f 00 55 48 89 e5 48 89 f2 48 8b 3f be 01 00 00 00 5d e9 e7 [ 4614.428775] RSP: 0018:ffffb95acfa4ba68 EFLAGS: 00010246 [ 4614.434609] RAX: 0000000000000000 RBX: 0000000000000010 RCX: 0000000000000000 [ 4614.442587] RDX: 0000000000000007 RSI: ffffb95acfa4ba70 RDI: ffffb95acfa4bc88 [ 4614.450557] RBP: ffffb95acfa4bae0 R08: ffff0a00ffffff05 R09: 0000000000000070 [ 4614.458527] R10: 0000000000000000 R11: ffffffffab67eaf0 R12: ffffb95acfa4bcc8 [ 4614.466493] R13: ffffffffac5d50f0 R14: 0000000000000000 R15: 0000000000000000 [ 4614.474473] ? __cfi__RNvXs5_NtNtNtCs3o2tGsuHyou_4core3fmt3num3impyNtB9_7Display3fmt+0x10/0x10 [ 4614.484118] ? _RNvNtCs3o2tGsuHyou_4core3fmt5write+0x1d2/0x250
This happens because core::fmt::write() calls core::fmt::rt::Argument::fmt(), which currently has CFI disabled:
library/core/src/fmt/rt.rs: 171 // FIXME: Transmuting formatter in new and indirectly branching to/calling 172 // it here is an explicit CFI violation. 173 #[allow(inline_no_sanitize)] 174 #[no_sanitize(cfi, kcfi)] 175 #[inline] 176 pub(super) unsafe fn fmt(&self, f: &mut Formatter<'_>) -> Result {
This causes a Control Protection exception, because FineIBT has sealed off the original function's endbr64.
This makes rust currently incompatible with FineIBT. Add a Kconfig dependency that prevents FineIBT from getting turned on by default if rust is enabled.
[ Rust 1.88.0 (scheduled for 2025-06-26) should have this fixed [1], and thus we relaxed the condition with Rust >= 1.88.
When objtool lands checking for this with e.g. [2], the plan is
to ideally run that in upstream Rust's CI to prevent regressions
early [3], since we do not control core's source code.
Alice tested the Rust PR backported to an older compiler.
Peter would like that Rust provides a stable core which can be
pulled into the kernel: "Relying on that much out of tree code is
'unfortunate'".
- Miguel ]
[ Reduced splat. - Miguel ]
{
"affected": [],
"aliases": [
"CVE-2025-38033"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-06-18T10:15:35Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/Kconfig: make CFI_AUTO_DEFAULT depend on !RUST or Rust \u003e= 1.88\n\nCalling core::fmt::write() from rust code while FineIBT is enabled\nresults in a kernel panic:\n\n[ 4614.199779] kernel BUG at arch/x86/kernel/cet.c:132!\n[ 4614.205343] Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI\n[ 4614.211781] CPU: 2 UID: 0 PID: 6057 Comm: dmabuf_dump Tainted: G U O 6.12.17-android16-0-g6ab38c534a43 #1 9da040f27673ec3945e23b998a0f8bd64c846599\n[ 4614.227832] Tainted: [U]=USER, [O]=OOT_MODULE\n[ 4614.241247] RIP: 0010:do_kernel_cp_fault+0xea/0xf0\n...\n[ 4614.398144] RIP: 0010:_RNvXs5_NtNtNtCs3o2tGsuHyou_4core3fmt3num3impyNtB9_7Display3fmt+0x0/0x20\n[ 4614.407792] Code: 48 f7 df 48 0f 48 f9 48 89 f2 89 c6 5d e9 18 fd ff ff 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 41 81 ea 14 61 af 2c 74 03 0f 0b 90 \u003c66\u003e 0f 1f 00 55 48 89 e5 48 89 f2 48 8b 3f be 01 00 00 00 5d e9 e7\n[ 4614.428775] RSP: 0018:ffffb95acfa4ba68 EFLAGS: 00010246\n[ 4614.434609] RAX: 0000000000000000 RBX: 0000000000000010 RCX: 0000000000000000\n[ 4614.442587] RDX: 0000000000000007 RSI: ffffb95acfa4ba70 RDI: ffffb95acfa4bc88\n[ 4614.450557] RBP: ffffb95acfa4bae0 R08: ffff0a00ffffff05 R09: 0000000000000070\n[ 4614.458527] R10: 0000000000000000 R11: ffffffffab67eaf0 R12: ffffb95acfa4bcc8\n[ 4614.466493] R13: ffffffffac5d50f0 R14: 0000000000000000 R15: 0000000000000000\n[ 4614.474473] ? __cfi__RNvXs5_NtNtNtCs3o2tGsuHyou_4core3fmt3num3impyNtB9_7Display3fmt+0x10/0x10\n[ 4614.484118] ? _RNvNtCs3o2tGsuHyou_4core3fmt5write+0x1d2/0x250\n\nThis happens because core::fmt::write() calls\ncore::fmt::rt::Argument::fmt(), which currently has CFI disabled:\n\nlibrary/core/src/fmt/rt.rs:\n171 // FIXME: Transmuting formatter in new and indirectly branching to/calling\n172 // it here is an explicit CFI violation.\n173 #[allow(inline_no_sanitize)]\n174 #[no_sanitize(cfi, kcfi)]\n175 #[inline]\n176 pub(super) unsafe fn fmt(\u0026self, f: \u0026mut Formatter\u003c\u0027_\u003e) -\u003e Result {\n\nThis causes a Control Protection exception, because FineIBT has sealed\noff the original function\u0027s endbr64.\n\nThis makes rust currently incompatible with FineIBT. Add a Kconfig\ndependency that prevents FineIBT from getting turned on by default\nif rust is enabled.\n\n[ Rust 1.88.0 (scheduled for 2025-06-26) should have this fixed [1],\n and thus we relaxed the condition with Rust \u003e= 1.88.\n\n When `objtool` lands checking for this with e.g. [2], the plan is\n to ideally run that in upstream Rust\u0027s CI to prevent regressions\n early [3], since we do not control `core`\u0027s source code.\n\n Alice tested the Rust PR backported to an older compiler.\n\n Peter would like that Rust provides a stable `core` which can be\n pulled into the kernel: \"Relying on that much out of tree code is\n \u0027unfortunate\u0027\".\n\n - Miguel ]\n\n[ Reduced splat. - Miguel ]",
"id": "GHSA-gxj3-8g3m-8hpw",
"modified": "2025-06-18T12:30:31Z",
"published": "2025-06-18T12:30:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38033"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5595c31c370957aabe739ac3996aedba8267603f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5a8d073d87da4ad1496b35adaee5719e94665d81"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6b9956d09382bcbd5fd260c4b60ec48680a4cffb"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.