CVE-2024-53210

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

s390/iucv: MSG_PEEK causes memory leak in iucv_sock_destruct()

Passing MSG_PEEK flag to skb_recv_datagram() increments skb refcount (skb->users) and iucv_sock_recvmsg() does not decrement skb refcount at exit. This results in skb memory leak in skb_queue_purge() and WARN_ON in iucv_sock_destruct() during socket close. To fix this decrease skb refcount by one if MSG_PEEK is set in order to prevent memory leak and WARN_ON.

WARNING: CPU: 2 PID: 6292 at net/iucv/af_iucv.c:286 iucv_sock_destruct+0x144/0x1a0 [af_iucv] CPU: 2 PID: 6292 Comm: afiucv_test_msg Kdump: loaded Tainted: G W 6.10.0-rc7 #1 Hardware name: IBM 3931 A01 704 (z/VM 7.3.0) Call Trace: [<001587c682c4aa98>] iucv_sock_destruct+0x148/0x1a0 [af_iucv] [<001587c682c4a9d0>] iucv_sock_destruct+0x80/0x1a0 [af_iucv] [<001587c704117a32>] __sk_destruct+0x52/0x550 [<001587c704104a54>] __sock_release+0xa4/0x230 [<001587c704104c0c>] sock_close+0x2c/0x40 [<001587c702c5f5a8>] __fput+0x2e8/0x970 [<001587c7024148c4>] task_work_run+0x1c4/0x2c0 [<001587c7023b0716>] do_exit+0x996/0x1050 [<001587c7023b13aa>] do_group_exit+0x13a/0x360 [<001587c7023b1626>] __s390x_sys_exit_group+0x56/0x60 [<001587c7022bccca>] do_syscall+0x27a/0x380 [<001587c7049a6a0c>] __do_syscall+0x9c/0x160 [<001587c7049ce8a8>] system_call+0x70/0x98 Last Breaking-Event-Address: [<001587c682c4a9d4>] iucv_sock_destruct+0x84/0x1a0 [af_iucv]

Weakness

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://git.kernel.org/stable/c/42251c2d1ef1cb0822638bebb87ad9120c759673
• https://git.kernel.org/stable/c/783c2c6e61c5a04eb8baea598753d5fa174dbe85
• https://git.kernel.org/stable/c/934326aef7ac4652f81c69d18bf44eebaefc39c3
• https://git.kernel.org/stable/c/9f603e66e1c59c1d25e60eb0636cb307d190782e
• https://git.kernel.org/stable/c/ebaf81317e42aa990ad20b113cfe3a7b20d4e937