CVE-2025-21755 Information

Description

In the Linux kernel the following vulnerability has been resolved:

vsock: Orphan socket after transport release

During socket release sock_orphan() is called without considering that it sets sk->sk_wq to NULL. Later if SO_LINGER is enabled this leads to a null pointer dereferenced in virtio_transport_wait_close().

Orphan the socket only after transport release.

Partially reverts the ‘Fixes:’ commit.

KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] lock_acquire+0x19e/0x500 _raw_spin_lock_irqsave+0x47/0x70 add_wait_queue+0x46/0x230 virtio_transport_release+0x4e7/0x7f0 __vsock_release+0xfd/0x490 vsock_release+0x90/0x120 __sock_release+0xa3/0x250 sock_close+0x14/0x20 __fput+0x35e/0xa90 __x64_sys_close+0x78/0xd0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Reference

https://git.kernel.org/stable/c/3a866f8376f0a5c848dcb59cd26df845fffbe6d8 https://git.kernel.org/stable/c/78dafe1cf3afa02ed71084b350713b07e72a18fb https://git.kernel.org/stable/c/94d81870eec7ad2dd7af80bffd314ded26caea1a https://git.kernel.org/stable/c/f3b8e9d3414b2eb083d8293be25a949fe480897b