CVE-2023-52698

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

calipso: fix memory leak in netlbl_calipso_add_pass()

If IPv6 support is disabled at boot (ipv6.disable=1), the calipso_init() -> netlbl_calipso_ops_register() function isnt called, and the netlbl_calipso_ops_get() function always returns NULL. In this case, the netlbl_calipso_add_pass() function allocates memory for the doi_def variable but doesnt free it with the calipso_doi_free().

BUG: memory leak unreferenced object 0xffff888011d68180 (size 64): comm syz-executor.1, pid 10746, jiffies 4295410986 (age 17.928s) hex dump (first 32 bytes): 00 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 ……………. 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ……………. backtrace: [<…>] kmalloc include/linux/slab.h:552 [inline] [<…>] netlbl_calipso_add_pass net/netlabel/netlabel_calipso.c:76 [inline] [<…>] netlbl_calipso_add+0x22e/0x4f0 net/netlabel/netlabel_calipso.c:111 [<…>] genl_family_rcv_msg_doit+0x22f/0x330 net/netlink/genetlink.c:739 [<…>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline] [<…>] genl_rcv_msg+0x341/0x5a0 net/netlink/genetlink.c:800 [<…>] netlink_rcv_skb+0x14d/0x440 net/netlink/af_netlink.c:2515 [<…>] genl_rcv+0x29/0x40 net/netlink/genetlink.c:811 [<…>] netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] [<…>] netlink_unicast+0x54b/0x800 net/netlink/af_netlink.c:1339 [<…>] netlink_sendmsg+0x90a/0xdf0 net/netlink/af_netlink.c:1934 [<…>] sock_sendmsg_nosec net/socket.c:651 [inline] [<…>] sock_sendmsg+0x157/0x190 net/socket.c:671 [<…>] ____sys_sendmsg+0x712/0x870 net/socket.c:2342 [<…>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2396 [<…>] __sys_sendmsg+0xea/0x1b0 net/socket.c:2429 [<…>] do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46 [<…>] entry_SYSCALL_64_after_hwframe+0x61/0xc6

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

[PM: merged via the LSM tree at Jakub Kicinski request]

Weakness

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

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/321b3a5592c8a9d6b654c7c64833ea67dbb33149
• https://git.kernel.org/stable/c/36e19f84634aaa94f543fedc0a07588949638d53
• https://git.kernel.org/stable/c/408bbd1e1746fe33e51f4c81c2febd7d3841d031
• https://git.kernel.org/stable/c/44a88650ba55e6a7f2ec485d2c2413ba7e216f01
• https://git.kernel.org/stable/c/9a8f811a146aa2a0230f8edb2e9f4b6609aab8da
• https://git.kernel.org/stable/c/a4529a08d3704c17ea9c7277d180e46b99250ded
• https://git.kernel.org/stable/c/ec4e9d630a64df500641892f4e259e8149594a99
• https://git.kernel.org/stable/c/f14d36e6e97fe935a20e0ceb159c100f90b6627c
• https://git.kernel.org/stable/c/321b3a5592c8a9d6b654c7c64833ea67dbb33149
• https://git.kernel.org/stable/c/36e19f84634aaa94f543fedc0a07588949638d53
• https://git.kernel.org/stable/c/408bbd1e1746fe33e51f4c81c2febd7d3841d031
• https://git.kernel.org/stable/c/44a88650ba55e6a7f2ec485d2c2413ba7e216f01
• https://git.kernel.org/stable/c/9a8f811a146aa2a0230f8edb2e9f4b6609aab8da
• https://git.kernel.org/stable/c/a4529a08d3704c17ea9c7277d180e46b99250ded
• https://git.kernel.org/stable/c/ec4e9d630a64df500641892f4e259e8149594a99
• https://git.kernel.org/stable/c/f14d36e6e97fe935a20e0ceb159c100f90b6627c
• https://lists.debian.org/debian-lts-announce/2024/06/msg00016.html
• https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html