CVE-2025-38723: LoongArch: BPF: Fix jump offset calculation in tailcall
Vulnerability summary
CVE-2025-38723 is a medium (CVSS 5.5) vulnerability in debian debian_linux. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 6% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 4Timeline
- 04-09-2025PublishedVulnerability first disclosed.
- 12-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Fix jump offset calculation in tailcall The extra pass of bpf_int_jit_compile() skips JIT context initialization which essentially skips offset calculation leaving out_offset = -1, so the jmp_offset in emit_bpf_tail_call is calculated by "#define jmp_offset (out_offset - (cur_offset))" is a negative number, which is wrong. The final generated assembly are as follow. 54: bgeu $a2, $t1, -8 # 0x0000004c 58: addi.d $a6, $s5, -1 5c: bltz $a6, -16 # 0x0000004c 60: alsl.d $t2, $a2, $a1, 0x3 64: ld.d $t2, $t2, 264 68: beq $t2, $zero, -28 # 0x0000004c Before apply this patch, the follow test case will reveal soft lock issues. cd tools/testing/selftests/bpf/ ./test_progs --allow=tailcalls/tailcall_bpf2bpf_1 dmesg: watchdog: BUG: soft lockup - CPU#2 stuck for 26s! [test_progs:25056]
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.17%
Chance of exploitation in the next 30 days
Percentile
6%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.17% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu85 products
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
- linux-aws-5.13All versions (No fix recorded)
- linux-aws-5.19All versions (No fix recorded)
Debian2 products
- linux< 6.1.153-1 | < 6.12.43-1 | < 6.16.3-1
- debian_linuxEOL11.0
Linux2 products
- linux≥ 5dc615520c4dfb358245680f1904bad61116648e, < 1a782fa32e644aa9fbae6c8488f3e61221ac96e1 | ≥ 5dc615520c4dfb358245680f1904bad61116648e, < 17c010fe45def335fe03a0718935416b04c7f349 | ≥ 5dc615520c4dfb358245680f1904bad61116648e, < f83d469e16bb1f75991ca67c56786fb2aaa42bea | ≥ 5dc615520c4dfb358245680f1904bad61116648e, < f2b5e50cc04d7a049b385bc1c93b9cbf5f10c94f | ≥ 5dc615520c4dfb358245680f1904bad61116648e, < 9262e3e04621558e875eb5afb5e726b648cd5949 | ≥ 5dc615520c4dfb358245680f1904bad61116648e, < cd39d9e6b7e4c58fa77783e7aedf7ada51d02ea3 | 6.1
- linux_kernel≥ 6.1, < 6.1.149 | ≥ 6.2, < 6.6.103 | ≥ 6.7, < 6.12.43 | ≥ 6.13, < 6.15.11 | ≥ 6.16, < 6.16.2
3 vendors · 89 products
