First published: Fri Jul 12 2024(Updated: )
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
Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Software | Affected Version | How to fix |
---|---|---|
Linux Linux kernel | >=4.19.272<4.19.317 | |
Linux Linux kernel | >=5.4.231<5.4.279 | |
Linux Linux kernel | >=5.10.166<5.10.221 | |
Linux Linux kernel | >=5.15.91<5.15.162 | |
Linux Linux kernel | >=6.1.9<6.1.96 | |
Linux Linux kernel | >=6.2<6.6.36 | |
Linux Linux kernel | >=6.7<6.9.7 | |
Linux Linux kernel | =6.10-rc1 | |
Linux Linux kernel | =6.10-rc2 | |
Linux Linux kernel | =6.10-rc3 | |
Linux Linux kernel | =6.10-rc4 | |
debian/linux | 5.10.223-1 5.10.226-1 6.1.106-3 6.1.112-1 6.11.5-1 6.11.6-1 |
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