CVE-2026-98061— bpf: Reject tail calls directly from callback frames
Quick assessment
Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
在 Linux 内核中，已解决以下漏洞： BPF：拒绝从回调帧直接发起的尾调用（tail call） 当从非零帧发起尾调用时，该操作被建模为从该帧返回。验证器（verifier）会将寄存器 R0 标记为未知状态，并对所选分支调用 。 当前帧若为同步回调（synchronous callback）， 会强制执行回调返回值契约，并将 R0 标记为“精确”（precise）。然而，由于尾调用路径中 R0 是合成的（synthesized），而非从指令推导得出，精度回溯（precision backtracking）在回溯
Possible ATT&CK Techniques 2 AI
T1564 · Hide Artifacts T1068 · Exploitation for Privilege EscalationAffected Version Matrix 9
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Linux | Linux | a6c22c91b6284e4713c0cf5b20ab3c9c71b77ae8< 617c8266e49f45747f71e74177646a63f72b7025 |
affected |
e3245f8990431950d20631c72236d4e8cb2dcde8< 96d31b28263c429a56e4de85bcf744a5c320b3a3 |
affected | ||
e3245f8990431950d20631c72236d4e8cb2dcde8< 266aa4ad0b2e82397cd9045752c9bff03d98eddd |
affected | ||
6.18.2< 6.18.53 |
affected | ||
6.19 |
affected | ||
< 6.19 |
unaffected | ||
6.18.53≤ 6.18.* |
unaffected | ||
7.2.7≤ 7.2.* |
unaffected | ||
| … +1 more rows | |||
Get alerts for future matching vulnerabilities
Log in to subscribe
I. Basic Information for CVE-2026-98061
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗
Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
bpf: Reject tail calls directly from callback frames
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject tail calls directly from callback frames
A tail call from a non-zero frame is modeled as a return from that frame.
The verifier makes R0 unknown and calls prepare_func_exit() for the taken
branch.
When the current frame is a synchronous callback, prepare_func_exit()
enforces the callback return-value contract and marks R0 precise. Since the
tail-call path synthesized R0 rather than deriving it from an instruction,
precision backtracking reaches the callback-calling instruction with R0
still requested and triggers the "callback unexpected regs" verifier bug.
A CAP_BPF task can therefore cause a WARN and an -EFAULT BPF_PROG_LOAD.
Tail calls reachable from callbacks are already rejected later by
check_max_stack_depth(). Reject a tail call made directly by a callback
before constructing the inconsistent return state, using the existing
diagnostic. Tail calls from ordinary subprograms keep their current
behavior.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Affected Products
II. Public POCs for CVE-2026-98061
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
Premium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2026-98061
请登录查看更多情报信息。
Patches & Fixes for CVE-2026-98061 (3)
Same Patch Batch · Linux · 2026-09-25 · 372 CVEs total
| CVE-2026-100075 | 9.8 CRITICAL | RDMA/srpt: Fix srpt_alloc_rw_ctxs() unwind counters |
| CVE-2026-97555 | 8.8 HIGH | smb: client: fix heap overflow in DACL owner/group rewrite |
| CVE-2026-97957 | 8.8 HIGH | net: hinic: fix mailbox segment buffer overflow |
| CVE-2026-97527 | 8.8 HIGH | scsi: qla2xxx: Serialize NVMe unsol ctx list with a per-fcport lock |
| CVE-2026-97528 | 8.8 HIGH | scsi: qla2xxx: Unlink NVMe unsol ctx before freeing on LS reject error |
| CVE-2026-98115 | 8.8 HIGH | ksmbd: safely drain sessions during logoff |
| CVE-2026-97525 | 8.2 HIGH | x86/mm/pat: Allocate split page tables as kernel page tables |
| CVE-2026-98069 | 8.1 HIGH | net/rds: acquire the fastpath locks in rds_conn_shutdown() |
| CVE-2026-97573 | 8.1 HIGH | bnxt_en: Handle buffer allocation failure in bnxt_rx_ring_reset() |
| CVE-2026-97570 | 8.1 HIGH | bnxt_en: Bound SW TPA IDs to prevent crashes |
| CVE-2026-98130 | 8.1 HIGH | sctp: fix a TOCTOU race in SCTP_CMD_TIMER_START |
| CVE-2026-98070 | 8.1 HIGH | net/rds: acquire RDS_IN_XMIT in rds_tcp_reset_callbacks() |
| CVE-2026-98002 | 7.8 HIGH | iommu/amd: Fix ineffective error check in nested domain allocation |
| CVE-2026-97575 | 7.8 HIGH | media: v4l2-ctrls: validate AV1 tile counts |
| CVE-2026-97576 | 7.8 HIGH | media: v4l2-ctrls: validate HEVC tile counts |
| CVE-2026-97941 | 7.8 HIGH | mm/slab: take n->list_lock in __slab_try_return_freelist() to avoid race |
| CVE-2026-98112 | 7.8 HIGH | ksmbd: fix listener task lifetime on netdev events |
| CVE-2026-97937 | 7.8 HIGH | ftrace: fork: Initialize function graph state before copy_exec_state() |
| CVE-2026-97580 | 7.8 HIGH | media: rkvdec: bound HEVC tile loops and PPS id to the array capacity |
| CVE-2026-97940 | 7.8 HIGH | ipv6: fix fib6 walker UAF on seq stop |
Showing top 20 of 372 CVEs. View all on vendor page → →
IV. Related Vulnerabilities
Same product: Linux
-
CVE-2026-98384
bpf: Fix out-of-bounds read of sk_protocol in bpf_sock_destr -
CVE-2026-98383
bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL -
CVE-2026-98382
bpf: Reject dev-bound-only programs on other devices -
CVE-2026-98381
veth: manage XDP program pointers during channel resize -
CVE-2026-98380
net/sched: reject IDR error pointers when deleting actions
Same vendor: Linux
-
CVE-2026-98384
bpf: Fix out-of-bounds read of sk_protocol in bpf_sock_destr -
CVE-2026-98383
bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL -
CVE-2026-98382
bpf: Reject dev-bound-only programs on other devices -
CVE-2026-98381
veth: manage XDP program pointers during channel resize -
CVE-2026-98380
net/sched: reject IDR error pointers when deleting actions
V. Comments for CVE-2026-98061
No comments yet