Description

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. [0]: https://syzkaller.appspot.com/bug?extid=d327a1f3b12e1e206c16

Metrics

 

CVSS Version 4.0 CVSS Version 3.x CVSS Version 2.0

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.

CVSS 4.0 Severity and Vector Strings:

NIST: NVD

N/A

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CVSS 3.x Severity and Vector Strings:

NIST: NVD

Base Score:  N/A

NVD assessment not yet provided.

CVSS 2.0 Severity and Vector Strings:

NIST: NVD

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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

kernel.org https://git.kernel.org/stable/c/0b9130247f3b6a1122478471ff0e014ea96bb735 [No types assigned]

kernel.org https://git.kernel.org/stable/c/280cf1173726a7059b628c610c71050d5c0b6937 [No types assigned]

kernel.org https://git.kernel.org/stable/c/5391f9db2cab5ef1cb411be1ab7dbec728078fba [No types assigned]

kernel.org https://git.kernel.org/stable/c/a02fd5d775cf9787ee7698c797e20f2fa13d2e2b [No types assigned]

kernel.org https://git.kernel.org/stable/c/b6ebe4fed73eedeb73f4540f8edc4871945474c8 [No types assigned]

kernel.org https://git.kernel.org/stable/c/d377f5a28332954b19e373d36823e59830ab1712 [No types assigned]

kernel.org https://git.kernel.org/stable/c/d616876256b38ecf9a1a1c7d674192c5346bc69c [No types assigned]

kernel.org https://git.kernel.org/stable/c/e07a9c2a850cdebf625e7a1b8171bd23a8554313 [No types assigned]