# CVE-2026-64188: net: qualcomm: rmnet: fix endpoint use-after-free in rmnet_dellink() CVE-2026-64188 is fixed in 16 products on 1 platform, first by DEBIAN-CVE-2026-64188, released July 21, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-64188 - Priority: High - CVSS: 7.8 (Moderate) - EPSS: 0.0012 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jul 20, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64188 ## Description In the Linux kernel, the following vulnerability has been resolved: net: qualcomm: rmnet: fix endpoint use-after-free in rmnet_dellink() rmnet_dellink() removes the endpoint from the hash table with hlist_del_init_rcu() and then immediately frees it with kfree(). However, RCU readers on the receive path (rmnet_rx_handler -> __rmnet_map_ingress_handler) may still hold a reference to the endpoint and dereference ep->egress_dev after the memory has been freed. The endpoint is a kmalloc-32 object, and the stale read at offset 8 corresponds to the egress_dev pointer. BUG: unable to handle page fault for address: ffffffffde942eef Oops: 0002 [#1] SMP NOPTI CPU: 1 UID: 0 PID: 137 Comm: poc_write Not tainted 7.0.0+ #4 PREEMPTLAZY RIP: 0010:rmnet_vnd_rx_fixup (rmnet_vnd.c:27) Call Trace: __rmnet_map_ingress_handler (rmnet_handlers.c:48 rmnet_handlers.c:101) rmnet_rx_handler (rmnet_handlers.c:129 rmnet_handlers.c:235) __netif_receive_skb_core.constprop.0 (net/core/dev.c:6096) __netif_receive_skb_one_core (net/core/dev.c:6208) netif_receive_skb (net/core/dev.c:6467) tun_get_user (drivers/net/tun.c:1955) tun_chr_write_iter (drivers/net/tun.c:2003) vfs_write (fs/read_write.c:688) ksys_write (fs/read_write.c:740) Add an rcu_head field to struct rmnet_endpoint and replace kfree() with kfree_rcu() so the endpoint memory remains valid through the RCU grace period. Also remove the rmnet_vnd_dellink() call and inline only the nr_rmnet_devs decrement, since rmnet_vnd_dellink() would set ep->egress_dev to NULL during the grace period, creating a data race with lockless readers. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-64kb sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-azure sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-default sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-default sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23237-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23237-1.md) | Aug 11, 2026 | | Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.37.1.160000.2.19 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.81.1.150700.17.45.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-default-base sles 16.0 | 6.12.0-160000.37.1.160000.2.19 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-docs sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-livepatch-SLE15-SP7-RT_Update_20 sles 15.7 | 1-150700.1.3.1 | [SUSE-SU-2026:4120-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4120-1.md) | Sep 10, 2026 | | Linux | kernel-livepatch-SLE15-SP7_Update_21 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-source sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-source sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-syms sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | linux Debian 12.15 (bookworm) | 6.1.177-1 | [DEBIAN-CVE-2026-64188](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64188.md) | Jul 21, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.95-1 | [DEBIAN-CVE-2026-64188](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64188.md) | Jul 21, 2026 | | Linux | linux Debian 14 | 7.0.14-1 | [DEBIAN-CVE-2026-64188](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64188.md) | Jul 21, 2026 | --- Data as of 2026-11-08T19:12:23Z UTC. 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