CVE - CVE-2025-21854

CVE-ID
CVE-2025-21854	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
In the Linux kernel, the following vulnerability has been resolved: sockmap, vsock: For connectible sockets allow only connected sockmap expects all vsocks to have a transport assigned, which is expressed in vsock_proto::psock_update_sk_prot(). However, there is an edge case where an unconnected (connectible) socket may lose its previously assigned transport. This is handled with a NULL check in the vsock/BPF recv path. Another design detail is that listening vsocks are not supposed to have any transport assigned at all. Which implies they are not supported by the sockmap. But this is complicated by the fact that a socket, before switching to TCP_LISTEN, may have had some transport assigned during a failed connect() attempt. Hence, we may end up with a listening vsock in a sockmap, which blows up quickly: KASAN: null-ptr-deref in range [0x0000000000000120-0x0000000000000127] CPU: 7 UID: 0 PID: 56 Comm: kworker/7:0 Not tainted 6.14.0-rc1+ Workqueue: vsock-loopback vsock_loopback_work RIP: 0010:vsock_read_skb+0x4b/0x90 Call Trace: sk_psock_verdict_data_ready+0xa4/0x2e0 virtio_transport_recv_pkt+0x1ca8/0x2acc vsock_loopback_work+0x27d/0x3f0 process_one_work+0x846/0x1420 worker_thread+0x5b3/0xf80 kthread+0x35a/0x700 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x1a/0x30 For connectible sockets, instead of relying solely on the state of vsk->transport, tell sockmap to only allow those representing established connections. This aligns with the behaviour for AF_INET and AF_UNIX.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/22b683217ad2112791a708693cb236507abd637a URL:https://git.kernel.org/stable/c/22b683217ad2112791a708693cb236507abd637a MISC:https://git.kernel.org/stable/c/8fb5bb169d17cdd12c2dcc2e96830ed487d77a0f URL:https://git.kernel.org/stable/c/8fb5bb169d17cdd12c2dcc2e96830ed487d77a0f MISC:https://git.kernel.org/stable/c/cc9a7832ede53ade1ba9991f0e27314caa4029d8 URL:https://git.kernel.org/stable/c/cc9a7832ede53ade1ba9991f0e27314caa4029d8 MISC:https://git.kernel.org/stable/c/f7b473e35986835cc2813fef7b9d40336a09247e URL:https://git.kernel.org/stable/c/f7b473e35986835cc2813fef7b9d40336a09247e
Assigning CNA
kernel.org
Date Record Created
20241229	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20241229)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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