Wind River Support Network

Description

In the Linux kernel, the following vulnerability has been resolved:EOL][EOL]net/smc: fix UAF on smcsk after smc_listen_out()[EOL][EOL]BPF CI testing report a UAF issue:[EOL][EOL]  [   16.446633] BUG: kernel NULL pointer dereference, address: 000000000000003  0[EOL]  [   16.447134] #PF: supervisor read access in kernel mod  e[EOL]  [   16.447516] #PF: error_code(0x0000) - not-present pag  e[EOL]  [   16.447878] PGD 0 P4D   0[EOL]  [   16.448063] Oops: Oops: 0000 [#1] PREEMPT SMP NOPT  I[EOL]  [   16.448409] CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Tainted: G           OE      6.13.0-rc3-g89e8a75fda73-dirty #4  2[EOL]  [   16.449124] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODUL  E[EOL]  [   16.449502] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/201  4[EOL]  [   16.450201] Workqueue: smc_hs_wq smc_listen_wor  k[EOL]  [   16.450531] RIP: 0010:smc_listen_work+0xc02/0x159  0[EOL]  [   16.452158] RSP: 0018:ffffb5ab40053d98 EFLAGS: 0001024  6[EOL]  [   16.452526] RAX: 0000000000000001 RBX: 0000000000000002 RCX: 000000000000030  0[EOL]  [   16.452994] RDX: 0000000000000280 RSI: 00003513840053f0 RDI: 000000000000000  0[EOL]  [   16.453492] RBP: ffffa097808e3800 R08: ffffa09782dba1e0 R09: 000000000000000  5[EOL]  [   16.453987] R10: 0000000000000000 R11: 0000000000000000 R12: ffffa0978274640  0[EOL]  [   16.454497] R13: 0000000000000000 R14: 0000000000000000 R15: ffffa09782d4092  0[EOL]  [   16.454996] FS:  0000000000000000(0000) GS:ffffa097bbc00000(0000) knlGS:000000000000000  0[EOL]  [   16.455557] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003  3[EOL]  [   16.455961] CR2: 0000000000000030 CR3: 0000000102788004 CR4: 0000000000770ef  0[EOL]  [   16.456459] PKRU: 5555555  4[EOL]  [   16.456654] Call Trace  :[EOL]  [   16.456832]  <TASK  >[EOL]  [   16.456989]  ? __die+0x23/0x7  0[EOL]  [   16.457215]  ? page_fault_oops+0x180/0x4c  0[EOL]  [   16.457508]  ? __lock_acquire+0x3e6/0x249  0[EOL]  [   16.457801]  ? exc_page_fault+0x68/0x20  0[EOL]  [   16.458080]  ? asm_exc_page_fault+0x26/0x3  0[EOL]  [   16.458389]  ? smc_listen_work+0xc02/0x159  0[EOL]  [   16.458689]  ? smc_listen_work+0xc02/0x159  0[EOL]  [   16.458987]  ? lock_is_held_type+0x8f/0x10  0[EOL]  [   16.459284]  process_one_work+0x1ea/0x6d  0[EOL]  [   16.459570]  worker_thread+0x1c3/0x38  0[EOL]  [   16.459839]  ? __pfx_worker_thread+0x10/0x1  0[EOL]  [   16.460144]  kthread+0xe0/0x11  0[EOL]  [   16.460372]  ? __pfx_kthread+0x10/0x1  0[EOL]  [   16.460640]  ret_from_fork+0x31/0x5  0[EOL]  [   16.460896]  ? __pfx_kthread+0x10/0x1  0[EOL]  [   16.461166]  ret_from_fork_asm+0x1a/0x3  0[EOL]  [   16.461453]  </TASK  >[EOL]  [   16.461616] Modules linked in: bpf_testmod(OE) [last unloaded: bpf_testmod(OE)  ][EOL]  [   16.462134] CR2: 000000000000003  0[EOL]  [   16.462380] ---[ end trace 0000000000000000 ]---[EOL]  [   16.462710] RIP: 0010:smc_listen_work+0xc02/0x1590[EOL][EOL]The direct cause of this issue is that after smc_listen_out_connected(),[EOL]newclcsock->sk may be NULL since it will releases the smcsk. Therefore,[EOL]if the application closes the socket immediately after accept,[EOL]newclcsock->sk can be NULL. A possible execution order could be as[EOL]follows:[EOL][EOL]smc_listen_work                                  ( userspace[EOL)-----------------------------------------------------------------EOL]lock_sock(sk)                                    ([EOL)smc_listen_out_connected()                      |EOL] ( \\- smc_listen_out                             |[EOL)|    | \\- release_sock                          |EOL]      ( |- sk->sk_data_ready()                   |[EOL)                                                | fd = accept();EOL]                                                 ( close(fd);[EOL)                                                |  \\- socket->sk = NULL;EOL]/* newclcsock->sk is NULL now */[EOL]SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk))[EOL][EOL]Since smc_listen_out_connected() will not fail, simply swapping the order[EOL]of the code can easily fix this issue.

CREATE(Triage):(User=admin) [CVE-2025-38734 (https://nvd.nist.gov/vuln/detail/CVE-2025-38734)