Linux Kernel up to 6.18.53/7.2.7/7.3-rc3 x86 kprobes int3_emulate_call memory corruption

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4.2$0-$5k0.54

Summaryinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 6.18.53/7.2.7/7.3-rc3. This affects the function int3_emulate_call of the component x86 kprobes. Performing a manipulation results in memory corruption. This vulnerability is reported as CVE-2026-98273. The attack requires a local approach. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 6.18.53/7.2.7/7.3-rc3. This affects the function int3_emulate_call of the component x86 kprobes. The manipulation with an unknown input leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ]

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-98273 since 09/25/2026. The exploitability is told to be easy. Attacking locally is a requirement. Additional levels of successful authentication are required for exploitation. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 6.18.54, 7.2.8 or 7.3-rc4 eliminates this vulnerability. Applying the patch cfc1af3d054aaabee08f1f77c441b3533b082869/d8c6a18c0552135cbf0c696c9019b2979d0862c9/a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.2

VulDB Base Score: 4.4
VulDB Temp Score: 4.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.54/7.2.8/7.3-rc4
Patch: cfc1af3d054aaabee08f1f77c441b3533b082869/d8c6a18c0552135cbf0c696c9019b2979d0862c9/a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255

Timelineinfo

09/25/2026 CVE reserved
10/06/2026 +11 days Advisory disclosed
10/06/2026 +0 days VulDB entry created
10/06/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98273 (🔒)
GCVE (CVE): GCVE-0-2026-98273
GCVE (VulDB): GCVE-100-414147

Entryinfo

Created: 10/06/2026 13:10
Changes: 10/06/2026 13:10 (59)
Complete: 🔍
Cache ID: 216::103

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