In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: Fix UAF in svc_tcp_listen_data_ready()
After the listener svc_sock is freed, and before invoking svc_tcp_accept() for the established child sock, there is a window that the newsock retaining a freed listener svc_sock in sk_user_data which cloning from parent. In the race window, if data is received on the newsock, we will observe use-after-free report in svc_tcp_listen_data_ready().
Reproduce by two tasks:
1. while :; do rpc.nfsd 0 ; rpc.nfsd; done 2. while :; do echo "" | ncat -4 127.0.0.1 2049 ; done
KASAN report:
================================================================== BUG: KASAN: slab-use-after-free in svc_tcp_listen_data_ready+0x1cf/0x1f0 [sunrpc] Read of size 8 at addr ffff888139d96228 by task nc/102553 CPU: 7 PID: 102553 Comm: nc Not tainted 6.3.0+ #18 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 Call Trace: <IRQ> dump_stack_lvl+0x33/0x50 print_address_description.constprop.0+0x27/0x310 print_report+0x3e/0x70 kasan_report+0xae/0xe0 svc_tcp_listen_data_ready+0x1cf/0x1f0 [sunrpc] tcp_data_queue+0x9f4/0x20e0 tcp_rcv_established+0x666/0x1f60 tcp_v4_do_rcv+0x51c/0x850 tcp_v4_rcv+0x23fc/0x2e80 ip_protocol_deliver_rcu+0x62/0x300 ip_local_deliver_finish+0x267/0x350 ip_local_deliver+0x18b/0x2d0 ip_rcv+0x2fb/0x370 __netif_receive_skb_one_core+0x166/0x1b0 process_backlog+0x24c/0x5e0 __napi_poll+0xa2/0x500 net_rx_action+0x854/0xc90 __do_softirq+0x1bb/0x5de do_softirq+0xcb/0x100 </IRQ> <TASK> ... </TASK>
Allocated by task 102371: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0x7b/0x90 svc_setup_socket+0x52/0x4f0 [sunrpc] svc_addsock+0x20d/0x400 [sunrpc] __write_ports_addfd+0x209/0x390 [nfsd] write_ports+0x239/0x2c0 [nfsd] nfsctl_transaction_write+0xac/0x110 [nfsd] vfs_write+0x1c3/0xae0 ksys_write+0xed/0x1c0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc
Freed by task 102551: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x50 __kasan_slab_free+0x106/0x190 __kmem_cache_free+0x133/0x270 svc_xprt_free+0x1e2/0x350 [sunrpc] svc_xprt_destroy_all+0x25a/0x440 [sunrpc] nfsd_put+0x125/0x240 [nfsd] nfsd_svc+0x2cb/0x3c0 [nfsd] write_threads+0x1ac/0x2a0 [nfsd] nfsctl_transaction_write+0xac/0x110 [nfsd] vfs_write+0x1c3/0xae0 ksys_write+0xed/0x1c0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc
Fix the UAF by simply doing nothing in svc_tcp_listen_data_ready() if state != TCP_LISTEN, that will avoid dereferencing svsk for all child socket.
CVSS Details
- CVSS 3.1 Base Score: 8.1
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade kernel-livepatch-5.10.192-182.736Upgrade perf-debuginfoUpgrade bpftool-debuginfoUpgrade kernel-toolsUpgrade python-perfUpgrade kernel-livepatch-5.15.122-77.145Upgrade kernel-debuginfo-common-aarch64Upgrade perfUpgrade kernel-tools-develUpgrade kernel-headersUpgrade python-perf-debuginfoUpgrade kernel-develUpgrade kernel-debuginfoUpgrade bpftoolUpgrade kernel-tools-debuginfoUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-livepatch-4.14.322-244.536Upgrade kernel | Mar 3, 2025 | Jul 14, 2024 |
| Amazon_linux | — | Upgrade kernel | Mar 2, 2025 | Sep 25, 2023 |
| Amazon_linux_2023 | — | Upgrade kernel-libbpf-develUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-headersUpgrade kernelUpgrade kernel-livepatch-6.1.41-63.109Upgrade perf-debuginfoUpgrade kernel-develUpgrade python3-perf-debuginfoUpgrade kernel-tools-debuginfoUpgrade kernel-libbpf-staticUpgrade bpftoolUpgrade kernel-libbpfUpgrade bpftool-debuginfoUpgrade kernel-debuginfoUpgrade kernel-tools-develUpgrade kernel-toolsUpgrade python3-perfUpgrade perfUpgrade kernel-debuginfo-common-aarch64 | Feb 26, 2025 | Jul 14, 2024 |
| Debian | — | Upgrade linux | Jul 30, 2024 | Jul 30, 2024 |
| Dell Powerstore Dsa2024462 | — | Upgrade Dell PowerStoreOS to the latest version | Oct 23, 2025 | Nov 20, 2024 |
| Dell Powerstore Dsa2024497 | — | Upgrade Dell PowerStoreOS to the latest version | Oct 23, 2025 | Dec 19, 2024 |
| Huawei Euleros 2_0_sp10 | — | Upgrade kernelUpgrade python3-perfUpgrade kernel-abi-stablelistsUpgrade kernel-toolsUpgrade kernel-tools-libs | Nov 11, 2024 | Jul 14, 2024 |
| Huawei Euleros 2_0_sp8 | — | Upgrade python-perfUpgrade kernelUpgrade kernel-headersUpgrade kernel-tools-libsUpgrade python3-perfUpgrade kernel-toolsUpgrade perfUpgrade kernel-develUpgrade bpftool | Jan 21, 2025 | Jul 14, 2024 |
| Huawei Euleros 2_0_sp9 | — | Upgrade kernel-tools-libsUpgrade kernel-toolsUpgrade python3-perfUpgrade kernel | Nov 11, 2024 | Jul 14, 2024 |
| Redhat_linux | — | No solution existsUpgrade kernel-rtUpgrade kernel | Sep 13, 2024 | Jul 14, 2024 |
| Suse | — | Upgrade ocfs2-kmp-azureUpgrade kernel-default-optionalUpgrade kernel-kvmsmall-livepatch-develUpgrade kernel-syms-rtUpgrade dtb-amazonUpgrade kernel-symsUpgrade ocfs2-kmp-rtUpgrade dtb-mediatekUpgrade dtb-renesasUpgrade kernel-default-extraUpgrade kernel-default-develUpgrade kernel-rt-develUpgrade kernel-azure-vdsoUpgrade gfs2-kmp-64kbUpgrade cluster-md-kmp-rtUpgrade kernel-kvmsmall-develUpgrade kernel-syms-azureUpgrade kselftests-kmp-64kbUpgrade gfs2-kmp-rtUpgrade kernel-debugUpgrade kernel-64kb-optionalUpgrade kernel-64kb-develUpgrade dlm-kmp-64kbUpgrade kernel-azure-extraUpgrade kernel-kvmsmallUpgrade cluster-md-kmp-defaultUpgrade dtb-xilinxUpgrade dlm-kmp-azureUpgrade dtb-amlogicUpgrade kernel-develUpgrade kernel-rt-livepatchUpgrade dtb-socionextUpgrade kselftests-kmp-defaultUpgrade dtb-appleUpgrade kernel-default-manUpgrade cluster-md-kmp-azureUpgrade kernel-rt-livepatch-develUpgrade kernel-devel-azureUpgrade dtb-hisiliconUpgrade kernel-devel-rtUpgrade kernel-debug-livepatch-develUpgrade dtb-amdUpgrade kernel-debug-develUpgrade kernel-64kbUpgrade reiserfs-kmp-defaultUpgrade kernel-azure-livepatch-develUpgrade dtb-armUpgrade dtb-apmUpgrade kernel-obs-qaUpgrade kernel-source-azureUpgrade kernel-zfcpdumpUpgrade kernel-64kb-livepatch-develUpgrade kernel-macrosUpgrade dtb-freescaleUpgrade kernel-sourceUpgrade kernel-rt_debug-vdsoUpgrade dtb-lgUpgrade dtb-exynosUpgrade dlm-kmp-defaultUpgrade cluster-md-kmp-64kbUpgrade kernel-rt_debugUpgrade kernel-defaultUpgrade kernel-preemptUpgrade dtb-alteraUpgrade reiserfs-kmp-rtUpgrade reiserfs-kmp-azureUpgrade kselftests-kmp-rtUpgrade dtb-broadcomUpgrade kernel-docs-htmlUpgrade kernel-azure-optionalUpgrade dtb-qcomUpgrade gfs2-kmp-azureUpgrade gfs2-kmp-defaultUpgrade kernel-azureUpgrade dtb-rockchipUpgrade dtb-marvellUpgrade dtb-allwinnerUpgrade kernel-default-livepatchUpgrade kernel-docsUpgrade kernel-debug-vdsoUpgrade kernel-azure-develUpgrade kernel-source-vanillaUpgrade kernel-rtUpgrade kernel-rt-vdsoUpgrade reiserfs-kmp-64kbUpgrade dlm-kmp-rtUpgrade kernel-default-vdsoUpgrade dtb-caviumUpgrade kernel-source-rtUpgrade kernel-default-base-rebuildUpgrade kernel-azure-baseUpgrade kernel-rt-extraUpgrade kernel-default-baseUpgrade kernel-rt-optionalUpgrade kselftests-kmp-azureUpgrade kernel-kvmsmall-vdsoUpgrade kernel-default-livepatch-develUpgrade ocfs2-kmp-defaultUpgrade ocfs2-kmp-64kbUpgrade kernel-rt_debug-livepatch-develUpgrade dtb-sprdUpgrade kernel-preempt-develUpgrade kernel-obs-buildUpgrade dtb-nvidiaUpgrade kernel-rt_debug-develUpgrade kernel-64kb-extra | Aug 15, 2024 | Jul 14, 2024 |
| Ubuntu | — | Upgrade linux-image-4.15.0-2100-azure-fipsUpgrade linux-image-aws-4.15Upgrade linux-image-aws-fips-4.15Upgrade linux-image-gcpUpgrade linux-image-virtual-hwe-16.04Upgrade linux-image-4.15.0-240-lowlatencyUpgrade linux-image-gcp-fipsUpgrade linux-image-kvmUpgrade linux-image-gcp-fips-4.15Upgrade linux-image-azure-4.15Upgrade linux-image-gcp-lts-18.04Upgrade linux-image-4.15.0-1138-fipsUpgrade linux-image-gcp-4.15Upgrade linux-image-genericUpgrade linux-image-lowlatencyUpgrade linux-image-4.15.0-240-genericUpgrade linux-image-azureUpgrade linux-image-4.15.0-1176-gcpUpgrade linux-image-azure-fipsUpgrade linux-image-aws-hweUpgrade linux-image-4.15.0-1166-kvmUpgrade linux-image-fipsUpgrade linux-image-4.15.0-1183-awsUpgrade linux-image-4.15.0-2121-aws-fipsUpgrade linux-image-virtualUpgrade linux-image-4.15.0-1191-azureUpgrade linux-image-lowlatency-hwe-16.04Upgrade linux-image-aws-lts-18.04Upgrade linux-image-azure-lts-18.04Upgrade linux-image-4.15.0-1145-oracleUpgrade linux-image-azure-fips-4.15Upgrade linux-image-oemUpgrade linux-image-4.15.0-2084-gcp-fipsUpgrade linux-image-oracle-4.15Upgrade linux-image-gkeUpgrade linux-image-generic-hwe-16.04Upgrade linux-image-oracleUpgrade linux-image-oracle-lts-18.04Upgrade linux-image-aws-fips | Nov 19, 2024 | Jul 14, 2024 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | May 27, 2026 | Jul 14, 2024 |
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