{"id":"DEBIAN-CVE-2023-52885","details":"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:    \u003cIRQ\u003e    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    \u003c/IRQ\u003e    \u003cTASK\u003e    ...    \u003c/TASK\u003e    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.","modified":"2026-09-15T09:03:02.085899637Z","published":"2024-07-14T08:15:01.823Z","upstream":["CVE-2023-52885"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2023-52885"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.52-1"}]}],"versions":["6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52885.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.4.4-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52885.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.4.4-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52885.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}