Memory Leak Affecting kernel-syms package, versions <6.4.0-150600.23.17.1

Note: Versions mentioned in the description apply only to the upstream kernel-syms package and not the kernel-syms package as distributed by SLES. See How to fix? for SLES:15.6 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

netrom: Fix a memory leak in nr_heartbeat_expiry()

syzbot reported a memory leak in nr_create() 0.

Commit 409db27e3a2e ("netrom: Fix use-after-free of a listening socket.") added sock_hold() to the nr_heartbeat_expiry() function, where a) a socket has a SOCK_DESTROY flag or b) a listening socket has a SOCK_DEAD flag.

But in the case "a," when the SOCK_DESTROY flag is set, the file descriptor has already been closed and the nr_release() function has been called. So it makes no sense to hold the reference count because no one will call another nr_destroy_socket() and put it as in the case "b."

nr_connect nr_establish_data_link nr_start_heartbeat

nr_release switch (nr->state) case NR_STATE_3 nr->state = NR_STATE_2 sock_set_flag(sk, SOCK_DESTROY);

                    nr_rx_frame
                      nr_process_rx_frame
                        switch (nr->state)
                        case NR_STATE_2
                          nr_state2_machine()
                            nr_disconnect()
                              nr_sk(sk)->state = NR_STATE_0
                              sock_set_flag(sk, SOCK_DEAD)

                nr_heartbeat_expiry
                  switch (nr->state)
                  case NR_STATE_0
                    if (sock_flag(sk, SOCK_DESTROY) ||
                       (sk->sk_state == TCP_LISTEN
                         && sock_flag(sk, SOCK_DEAD)))
                       sock_hold()  // ( !!! )
                       nr_destroy_socket()

To fix the memory leak, let's call sock_hold() only for a listening socket.

Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with Syzkaller.

• https://www.suse.com/security/cve/CVE-2024-41006.html
• https://bugzilla.suse.com/1227862
• https://git.kernel.org/stable/c/0b9130247f3b6a1122478471ff0e014ea96bb735
• https://git.kernel.org/stable/c/280cf1173726a7059b628c610c71050d5c0b6937
• https://git.kernel.org/stable/c/5391f9db2cab5ef1cb411be1ab7dbec728078fba
• https://git.kernel.org/stable/c/a02fd5d775cf9787ee7698c797e20f2fa13d2e2b
• https://git.kernel.org/stable/c/b6ebe4fed73eedeb73f4540f8edc4871945474c8
• https://git.kernel.org/stable/c/d377f5a28332954b19e373d36823e59830ab1712
• https://git.kernel.org/stable/c/d616876256b38ecf9a1a1c7d674192c5346bc69c
• https://git.kernel.org/stable/c/e07a9c2a850cdebf625e7a1b8171bd23a8554313