Bug 2348609 (CVE-2025-21756)
| Summary: | CVE-2025-21756 kernel: vsock: Keep the binding until socket destruction | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | high | Docs Contact: | |
| Priority: | high | ||
| Version: | unspecified | CC: | dfreiber, drow, jburrell, michael.h.hall-1, vkumar |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: |
A flaw was found in the Linux kernel's virtual socket protocol network driver, where an improperly timed socket unbinding could result in a use-after-free issue. This flaw allows an attacker who can create and destroy arbitrary connections on virtual connections to read or modify system memory, potentially leading to an escalation of privileges or the compromise of sensitive data.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2025022603-CVE-2025-21756-5e09@gregkh/T This issue has been addressed in the following products: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions Red Hat Enterprise Linux 8.6 Telecommunications Update Service Via RHSA-2025:7652 https://access.redhat.com/errata/RHSA-2025:7652 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Extended Update Support Via RHSA-2025:7676 https://access.redhat.com/errata/RHSA-2025:7676 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.8 Extended Update Support Via RHSA-2025:7682 https://access.redhat.com/errata/RHSA-2025:7682 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Extended Update Support Via RHSA-2025:7683 https://access.redhat.com/errata/RHSA-2025:7683 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions Via RHSA-2025:7896 https://access.redhat.com/errata/RHSA-2025:7896 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.4 Telecommunications Update Service Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions Via RHSA-2025:7902 https://access.redhat.com/errata/RHSA-2025:7902 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.4 Telecommunications Update Service Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions Via RHSA-2025:7901 https://access.redhat.com/errata/RHSA-2025:7901 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions Via RHSA-2025:7897 https://access.redhat.com/errata/RHSA-2025:7897 This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2025:7903 https://access.redhat.com/errata/RHSA-2025:7903 This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2025:8056 https://access.redhat.com/errata/RHSA-2025:8056 This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2025:8057 https://access.redhat.com/errata/RHSA-2025:8057 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.4 Extended Update Support Via RHSA-2025:8058 https://access.redhat.com/errata/RHSA-2025:8058 This issue has been addressed in the following products: Red Hat Enterprise Linux 10 Via RHSA-2025:8137 https://access.redhat.com/errata/RHSA-2025:8137 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.4 Extended Update Support Via RHSA-2025:8248 https://access.redhat.com/errata/RHSA-2025:8248 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.4 Extended Update Support Via RHSA-2025:8342 https://access.redhat.com/errata/RHSA-2025:8342 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions Via RHSA-2025:8344 https://access.redhat.com/errata/RHSA-2025:8344 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.8 Extended Update Support Via RHSA-2025:8346 https://access.redhat.com/errata/RHSA-2025:8346 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Extended Update Support Via RHSA-2025:8343 https://access.redhat.com/errata/RHSA-2025:8343 This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2025:8345 https://access.redhat.com/errata/RHSA-2025:8345 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions Via RHSA-2025:8348 https://access.redhat.com/errata/RHSA-2025:8348 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions Via RHSA-2025:8347 https://access.redhat.com/errata/RHSA-2025:8347 |
In the Linux kernel, the following vulnerability has been resolved: vsock: Keep the binding until socket destruction Preserve sockets bindings; this includes both resulting from an explicit bind() and those implicitly bound through autobind during connect(). Prevents socket unbinding during a transport reassignment, which fixes a use-after-free: 1. vsock_create() (refcnt=1) calls vsock_insert_unbound() (refcnt=2) 2. transport->release() calls vsock_remove_bound() without checking if sk was bound and moved to bound list (refcnt=1) 3. vsock_bind() assumes sk is in unbound list and before __vsock_insert_bound(vsock_bound_sockets()) calls __vsock_remove_bound() which does: list_del_init(&vsk->bound_table); // nop sock_put(&vsk->sk); // refcnt=0 BUG: KASAN: slab-use-after-free in __vsock_bind+0x62e/0x730 Read of size 4 at addr ffff88816b46a74c by task a.out/2057 dump_stack_lvl+0x68/0x90 print_report+0x174/0x4f6 kasan_report+0xb9/0x190 __vsock_bind+0x62e/0x730 vsock_bind+0x97/0xe0 __sys_bind+0x154/0x1f0 __x64_sys_bind+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Allocated by task 2057: kasan_save_stack+0x1e/0x40 kasan_save_track+0x10/0x30 __kasan_slab_alloc+0x85/0x90 kmem_cache_alloc_noprof+0x131/0x450 sk_prot_alloc+0x5b/0x220 sk_alloc+0x2c/0x870 __vsock_create.constprop.0+0x2e/0xb60 vsock_create+0xe4/0x420 __sock_create+0x241/0x650 __sys_socket+0xf2/0x1a0 __x64_sys_socket+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Freed by task 2057: kasan_save_stack+0x1e/0x40 kasan_save_track+0x10/0x30 kasan_save_free_info+0x37/0x60 __kasan_slab_free+0x4b/0x70 kmem_cache_free+0x1a1/0x590 __sk_destruct+0x388/0x5a0 __vsock_bind+0x5e1/0x730 vsock_bind+0x97/0xe0 __sys_bind+0x154/0x1f0 __x64_sys_bind+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e refcount_t: addition on 0; use-after-free. WARNING: CPU: 7 PID: 2057 at lib/refcount.c:25 refcount_warn_saturate+0xce/0x150 RIP: 0010:refcount_warn_saturate+0xce/0x150 __vsock_bind+0x66d/0x730 vsock_bind+0x97/0xe0 __sys_bind+0x154/0x1f0 __x64_sys_bind+0x6e/0xb0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e refcount_t: underflow; use-after-free. WARNING: CPU: 7 PID: 2057 at lib/refcount.c:28 refcount_warn_saturate+0xee/0x150 RIP: 0010:refcount_warn_saturate+0xee/0x150 vsock_remove_bound+0x187/0x1e0 __vsock_release+0x383/0x4a0 vsock_release+0x90/0x120 __sock_release+0xa3/0x250 sock_close+0x14/0x20 __fput+0x359/0xa80 task_work_run+0x107/0x1d0 do_exit+0x847/0x2560 do_group_exit+0xb8/0x250 __x64_sys_exit_group+0x3a/0x50 x64_sys_call+0xfec/0x14f0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e