CVE-2026-43011
net/x25: Fix potential double free of skb
- State
- Published
- Severity
- 9.8 Critical
- Published
- May 1, 2026
- Updated
- Oct 19, 2026
- Reserved
- May 1, 2026
Description
In the Linux kernel, the following vulnerability has been resolved:
net/x25: Fix potential double free of skb
When alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at line 48 and returns 1 (error). This error propagates back through the call chain:
x25_queue_rx_frame returns 1 | v x25_state3_machine receives the return value 1 and takes the else branch at line 278, setting queued=0 and returning 0 | v x25_process_rx_frame returns queued=0 | v x25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb) again
This would free the same skb twice. Looking at x25_backlog_rcv:
net/x25/x25_in.c:x25_backlog_rcv() { ... queued = x25_process_rx_frame(sk, skb); ... if (!queued) kfree_skb(skb); }
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | Linux |
Weaknesses
- CWE-415 Double Free
Affected Products
| Product | Versions |
|---|---|
LinuxLinux |
|
LinuxLinux |
|
References
- https://git.kernel.org/stable/c/5d0aa038a90b30c9bedde0c41c1fdcd98ecb16e9
- https://git.kernel.org/stable/c/3f5e3005984645bf5bd129c6b13149879580b1fb
- https://git.kernel.org/stable/c/f782dd382203b2a8c4552a628431b7de65a19a7b
- https://git.kernel.org/stable/c/143d4fa68ae9efb83b0c55b12cc7f0d03732a2b1
- https://git.kernel.org/stable/c/524371398d8463ea7e101fce2cbf3915645d1730
- https://git.kernel.org/stable/c/fa1dbc93530b34fab0da9862426fe9c918c74dc0
- https://git.kernel.org/stable/c/c87dd137c0dad07cc55f98181ff380b0c23d2878
- https://git.kernel.org/stable/c/d10a26aa4d072320530e6968ef945c8c575edf61
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
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