bpf, arm64: set up the frame pointer for the exception callback
In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: set up the frame pointer for the exception callback A program acting as exception boundary saves all callee-saved registers, so build_prologue() takes the exception_cb path and never calls push_callee_regs(). That is the only place find_used_callee_regs() runs, and with it the only place ctx->fp_used is set, so the callback prologue does not emit the mov x25, sp that points BPF_REG_FP at the frame the callback runs on. x25 keeps whatever it held when bpf_throw() was called. If the throw came from a subprogram that uses its own BPF stack, that is the subprogram's frame pointer, and since the subprogram never returns it never restores x25 either. Stack accesses through BPF_REG_FP are rewritten to be stack pointer relative, so those still land in the callback's own frame. Materializing the register does not: a callback that passes the address of a local variable to a helper hands over an address in the dead subprogram's frame. That address is below the callback's stack pointer by then, and the helper's own call chain covers it, so the helper can write over its own return address. 0x1234 below is the value the helper was asked to store: pc : 0x1234 lr : 0x1234 Call trace: 0x1234 (P) bpf_test_run+0x188/0x3e0 bpf_prog_test_run_skb+0x47c/0x998 __sys_bpf+0xbdc/0xdd8 Kernel panic - not syncing: Oops: Fatal exception in interrupt Set ctx->fp_used on the exception callback path so that the existing code furt
CVE-2026-98641
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-98641
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5d4fa9ec5643a5c75d3c1e6abf50fb9284caf1ff",
"lessThan": "ecdd770a9fc3eaf6c3127c5991312b84774a7b0f",
"versionType": "git"
},
{
"status": "affected",
"version": "5d4fa9ec5643a5c75d3c1e6abf50fb9284caf1ff",
"lessThan": "b67b4c763f211e7a6391c356fef552e2ea63f08a",
"versionType": "git"
},
{
"status": "affected",
"version": "5d4fa9ec5643a5c75d3c1e6abf50fb9284caf1ff",
"lessThan": "d7cd5ebe13989f265015910faa25e5d50faa4c22",
"versionType": "git"
},
{
"status": "affected",
"version": "5d4fa9ec5643a5c75d3c1e6abf50fb9284caf1ff",
"lessThan": "ef1fb82f12186dd26153b14d9fbcf4ec98db81b3",
"versionType": "git"
}
],
"programFiles": [
"arch/arm64/net/bpf_jit_comp.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.12"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.12",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/arm64/net/bpf_jit_comp.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98641
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38660 · Revision 1
- Added to Heist Feed
- Publisher date