GHSA-787P-86V4-HHFG
Vulnerability from github – Published: 2026-02-18 15:31 – Updated: 2026-02-18 15:31In the Linux kernel, the following vulnerability has been resolved:
riscv: trace: fix snapshot deadlock with sbi ecall
If sbi_ecall.c's functions are traceable,
echo "__sbi_ecall:snapshot" > /sys/kernel/tracing/set_ftrace_filter
may get the kernel into a deadlock.
(Functions in sbi_ecall.c are excluded from tracing if CONFIG_RISCV_ALTERNATIVE_EARLY is set.)
__sbi_ecall triggers a snapshot of the ringbuffer. The snapshot code raises an IPI interrupt, which results in another call to __sbi_ecall and another snapshot...
All it takes to get into this endless loop is one initial __sbi_ecall. On RISC-V systems without SSTC extension, the clock events in timer-riscv.c issue periodic sbi ecalls, making the problem easy to trigger.
Always exclude the sbi_ecall.c functions from tracing to fix the potential deadlock.
sbi ecalls can easiliy be logged via trace events, excluding ecall functions from function tracing is not a big limitation.
{
"affected": [],
"aliases": [
"CVE-2026-23217"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-02-18T15:18:43Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nriscv: trace: fix snapshot deadlock with sbi ecall\n\nIf sbi_ecall.c\u0027s functions are traceable,\n\necho \"__sbi_ecall:snapshot\" \u003e /sys/kernel/tracing/set_ftrace_filter\n\nmay get the kernel into a deadlock.\n\n(Functions in sbi_ecall.c are excluded from tracing if\nCONFIG_RISCV_ALTERNATIVE_EARLY is set.)\n\n__sbi_ecall triggers a snapshot of the ringbuffer. The snapshot code\nraises an IPI interrupt, which results in another call to __sbi_ecall\nand another snapshot...\n\nAll it takes to get into this endless loop is one initial __sbi_ecall.\nOn RISC-V systems without SSTC extension, the clock events in\ntimer-riscv.c issue periodic sbi ecalls, making the problem easy to\ntrigger.\n\nAlways exclude the sbi_ecall.c functions from tracing to fix the\npotential deadlock.\n\nsbi ecalls can easiliy be logged via trace events, excluding ecall\nfunctions from function tracing is not a big limitation.",
"id": "GHSA-787p-86v4-hhfg",
"modified": "2026-02-18T15:31:27Z",
"published": "2026-02-18T15:31:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23217"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b0d7f5f0c9f05f1b6d4ee7110f15bef9c11f9df0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b1f8285bc8e3508c1fde23b5205f1270215d4984"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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