VDB-315908 · CVE-2025-38279 · EUVD-2025-20969

Linux Kernel prior 6.15.3/6.16-rc1 bpf kernel/bpf/verifier.c privilege escalation

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6.1	$0-$5k	0.00

Summaryinfo

A vulnerability described as problematic has been identified in Linux Kernel up to 6.15.2/fc2778c42f99c7de52fc004157b3c3ee4dcc208a. Affected is an unknown function of the file kernel/bpf/verifier.c of the component bpf. Such manipulation leads to an unknown weakness. This vulnerability is listed as CVE-2025-38279. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.15.2/fc2778c42f99c7de52fc004157b3c3ee4dcc208a. It has been rated as problematic. Affected by this issue is an unknown code block of the file kernel/bpf/verifier.c of the component bpf. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: bpf: Do not include stack ptr register in precision backtracking bookkeeping Yi Lai reported an issue ([1]) where the following warning appears in kernel dmesg: [ 60.643604] verifier backtracking bug [ 60.643635] WARNING: CPU: 10 PID: 2315 at kernel/bpf/verifier.c:4302 __mark_chain_precision+0x3a6c/0x3e10 [ 60.648428] Modules linked in: bpf_testmod(OE) [ 60.650471] CPU: 10 UID: 0 PID: 2315 Comm: test_progs Tainted: G OE 6.15.0-rc4-gef11287f8289-dirty #327 PREEMPT(full) [ 60.654385] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [ 60.656682] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 60.660475] RIP: 0010:__mark_chain_precision+0x3a6c/0x3e10 [ 60.662814] Code: 5a 30 84 89 ea e8 c4 d9 01 00 80 3d 3e 7d d8 04 00 0f 85 60 fa ff ff c6 05 31 7d d8 04 01 48 c7 c7 00 58 30 84 e8 c4 06 a5 ff <0f> 0b e9 46 fa ff ff 48 ... [ 60.668720] RSP: 0018:ffff888116cc7298 EFLAGS: 00010246 [ 60.671075] RAX: 54d70e82dfd31900 RBX: ffff888115b65e20 RCX: 0000000000000000 [ 60.673659] RDX: 0000000000000001 RSI: 0000000000000004 RDI: 00000000ffffffff [ 60.676241] RBP: 0000000000000400 R08: ffff8881f6f23bd3 R09: 1ffff1103ede477a [ 60.678787] R10: dffffc0000000000 R11: ffffed103ede477b R12: ffff888115b60ae8 [ 60.681420] R13: 1ffff11022b6cbc4 R14: 00000000fffffff2 R15: 0000000000000001 [ 60.684030] FS: 00007fc2aedd80c0(0000) GS:ffff88826fa8a000(0000) knlGS:0000000000000000 [ 60.686837] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 60.689027] CR2: 000056325369e000 CR3: 000000011088b002 CR4: 0000000000370ef0 [ 60.691623] Call Trace: [ 60.692821] <TASK> [ 60.693960] ? __pfx_verbose+0x10/0x10 [ 60.695656] ? __pfx_disasm_kfunc_name+0x10/0x10 [ 60.697495] check_cond_jmp_op+0x16f7/0x39b0 [ 60.699237] do_check+0x58fa/0xab10 ... Further analysis shows the warning is at line 4302 as below: 4294 /* static subprog call instruction, which 4295 * means that we are exiting current subprog, 4296 * so only r1-r5 could be still requested as 4297 * precise, r0 and r6-r10 or any stack slot in 4298 * the current frame should be zero by now 4299 */ 4300 if (bt_reg_mask(bt) & ~BPF_REGMASK_ARGS) { 4301 verbose(env, "BUG regs %x\n", bt_reg_mask(bt)); 4302 WARN_ONCE(1, "verifier backtracking bug"); 4303 return -EFAULT; 4304 } With the below test (also in the next patch): __used __naked static void __bpf_jmp_r10(void) { asm volatile ( "r2 = 2314885393468386424 ll;" "goto +0;" "if r2 <= r10 goto +3;" "if r1 >= -1835016 goto +0;" "if r2 <= 8 goto +0;" "if r3 <= 0 goto +0;" "exit;" ::: __clobber_all); } SEC("?raw_tp") __naked void bpf_jmp_r10(void) { asm volatile ( "r3 = 0 ll;" "call __bpf_jmp_r10;" "r0 = 0;" "exit;" ::: __clobber_all); } The following is the verifier failure log: 0: (18) r3 = 0x0 ; R3_w=0 2: (85) call pc+2 caller: R10=fp0 callee: frame1: R1=ctx() R3_w=0 R10=fp0 5: frame1: R1=ctx() R3_w=0 R10=fp0 ; asm volatile (" \ @ verifier_precision.c:184 5: (18) r2 = 0x20202000256c6c78 ; frame1: R2_w=0x20202000256c6c78 7: (05) goto pc+0 8: (bd) if r2 <= r10 goto pc+3 ; frame1: R2_w=0x20202000256c6c78 R10=fp0 9: (35) if r1 >= 0xffe3fff8 goto pc+0 ; frame1: R1=ctx() 10: (b5) if r2 <= 0x8 goto pc+0 mark_precise: frame1: last_idx 10 first_idx 0 subseq_idx -1 mark_precise: frame1: regs=r2 stack= before 9: (35) if r1 >= 0xffe3fff8 goto pc+0 mark_precise: frame1: regs=r2 stack= before 8: (bd) if r2 <= r10 goto pc+3 mark_preci ---truncated---

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-38279 since 04/16/2025. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 253428 (SUSE SLES15 Security Update : kernel (SUSE-SU-2025:02923-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.15.3 or 6.16-rc1 eliminates this vulnerability. Applying the patch ac49b7560b4b08b1e4043a29214cc7ad77644c00/e2d2115e56c4a02377189bfc3a9a7933552a7b0f is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (253428), EUVD (EUVD-2025-20969) and CERT Bund (WID-SEC-2025-1522). Once again VulDB remains the best source for vulnerability data.

Affected

Google Container-Optimized OS
Debian Linux
Amazon Linux 2
Red Hat Enterprise Linux
Ubuntu Linux
SUSE Linux
Oracle Linux
IBM QRadar SIEM
SUSE openSUSE
RESF Rocky Linux
Open Source Linux Kernel
Dell Avamar
Dell NetWorker

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

License

open-source

Website

Vendor: https://www.kernel.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.2
VulDB Meta Temp Score: 6.1

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒