SUSE: CVE-2025-21756: SUSE Linux Security Advisory
Description
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
Solution(s)
- suse-upgrade-cluster-md-kmp-64kb
- suse-upgrade-cluster-md-kmp-azure
- suse-upgrade-cluster-md-kmp-default
- suse-upgrade-cluster-md-kmp-rt
- suse-upgrade-dlm-kmp-64kb
- suse-upgrade-dlm-kmp-azure
- suse-upgrade-dlm-kmp-default
- suse-upgrade-dlm-kmp-rt
- suse-upgrade-dtb-allwinner
- suse-upgrade-dtb-altera
- suse-upgrade-dtb-amazon
- suse-upgrade-dtb-amd
- suse-upgrade-dtb-amlogic
- suse-upgrade-dtb-apm
- suse-upgrade-dtb-apple
- suse-upgrade-dtb-arm
- suse-upgrade-dtb-broadcom
- suse-upgrade-dtb-cavium
- suse-upgrade-dtb-exynos
- suse-upgrade-dtb-freescale
- suse-upgrade-dtb-hisilicon
- suse-upgrade-dtb-lg
- suse-upgrade-dtb-marvell
- suse-upgrade-dtb-mediatek
- suse-upgrade-dtb-nvidia
- suse-upgrade-dtb-qcom
- suse-upgrade-dtb-renesas
- suse-upgrade-dtb-rockchip
- suse-upgrade-dtb-socionext
- suse-upgrade-dtb-sprd
- suse-upgrade-dtb-xilinx
- suse-upgrade-gfs2-kmp-64kb
- suse-upgrade-gfs2-kmp-azure
- suse-upgrade-gfs2-kmp-default
- suse-upgrade-gfs2-kmp-rt
- suse-upgrade-kernel-64kb
- suse-upgrade-kernel-64kb-devel
- suse-upgrade-kernel-64kb-extra
- suse-upgrade-kernel-64kb-optional
- suse-upgrade-kernel-azure
- suse-upgrade-kernel-azure-devel
- suse-upgrade-kernel-azure-extra
- suse-upgrade-kernel-azure-optional
- suse-upgrade-kernel-azure-vdso
- suse-upgrade-kernel-debug
- suse-upgrade-kernel-debug-devel
- suse-upgrade-kernel-debug-vdso
- suse-upgrade-kernel-default
- suse-upgrade-kernel-default-base
- suse-upgrade-kernel-default-base-rebuild
- suse-upgrade-kernel-default-devel
- suse-upgrade-kernel-default-extra
- suse-upgrade-kernel-default-livepatch
- suse-upgrade-kernel-default-livepatch-devel
- suse-upgrade-kernel-default-optional
- suse-upgrade-kernel-default-vdso
- suse-upgrade-kernel-devel
- suse-upgrade-kernel-devel-azure
- suse-upgrade-kernel-devel-rt
- suse-upgrade-kernel-docs
- suse-upgrade-kernel-docs-html
- suse-upgrade-kernel-kvmsmall
- suse-upgrade-kernel-kvmsmall-devel
- suse-upgrade-kernel-kvmsmall-vdso
- suse-upgrade-kernel-macros
- suse-upgrade-kernel-obs-build
- suse-upgrade-kernel-obs-qa
- suse-upgrade-kernel-rt
- suse-upgrade-kernel-rt-devel
- suse-upgrade-kernel-rt-extra
- suse-upgrade-kernel-rt-livepatch-devel
- suse-upgrade-kernel-rt-optional
- suse-upgrade-kernel-rt-vdso
- suse-upgrade-kernel-rt_debug
- suse-upgrade-kernel-rt_debug-devel
- suse-upgrade-kernel-rt_debug-vdso
- suse-upgrade-kernel-source
- suse-upgrade-kernel-source-azure
- suse-upgrade-kernel-source-rt
- suse-upgrade-kernel-source-vanilla
- suse-upgrade-kernel-syms
- suse-upgrade-kernel-syms-azure
- suse-upgrade-kernel-syms-rt
- suse-upgrade-kernel-zfcpdump
- suse-upgrade-kselftests-kmp-64kb
- suse-upgrade-kselftests-kmp-azure
- suse-upgrade-kselftests-kmp-default
- suse-upgrade-kselftests-kmp-rt
- suse-upgrade-ocfs2-kmp-64kb
- suse-upgrade-ocfs2-kmp-azure
- suse-upgrade-ocfs2-kmp-default
- suse-upgrade-ocfs2-kmp-rt
- suse-upgrade-reiserfs-kmp-64kb
- suse-upgrade-reiserfs-kmp-azure
- suse-upgrade-reiserfs-kmp-default
- suse-upgrade-reiserfs-kmp-rt
- Lightweight Endpoint Agent
- Live Dashboards
- Real Risk Prioritization
- IT-Integrated Remediation Projects
- Cloud, Virtual, and Container Assessment
- Integrated Threat Feeds
- Easy-to-Use RESTful API
- Automation-Assisted Patching
- Automated Containment
With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.
– Scott Cheney, Manager of Information Security, Sierra View Medical Center