CVE-2025-38033
Intel FineIBT Rust Format String Vulnerability
Description
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 ]
INFO
Published Date :
June 18, 2025, 10:15 a.m.
Last Modified :
June 18, 2025, 1:46 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the affected packages.
- If necessary, update the Linux kernel.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-38033.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-38033 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-38033
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-38033 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-38033 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 18, 2025
Action Type Old Value New Value Added Description 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 ] Added Reference https://git.kernel.org/stable/c/5595c31c370957aabe739ac3996aedba8267603f Added Reference https://git.kernel.org/stable/c/5a8d073d87da4ad1496b35adaee5719e94665d81 Added Reference https://git.kernel.org/stable/c/6b9956d09382bcbd5fd260c4b60ec48680a4cffb