CVE-2023-52999

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net: fix UaF in netns ops registration error path<br /> <br /> If net_assign_generic() fails, the current error path in ops_init() tries<br /> to clear the gen pointer slot. Anyway, in such error path, the gen pointer<br /> itself has not been modified yet, and the existing and accessed one is<br /> smaller than the accessed index, causing an out-of-bounds error:<br /> <br /> BUG: KASAN: slab-out-of-bounds in ops_init+0x2de/0x320<br /> Write of size 8 at addr ffff888109124978 by task modprobe/1018<br /> <br /> CPU: 2 PID: 1018 Comm: modprobe Not tainted 6.2.0-rc2.mptcp_ae5ac65fbed5+ #1641<br /> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.1-2.fc37 04/01/2014<br /> Call Trace:<br /> <br /> dump_stack_lvl+0x6a/0x9f<br /> print_address_description.constprop.0+0x86/0x2b5<br /> print_report+0x11b/0x1fb<br /> kasan_report+0x87/0xc0<br /> ops_init+0x2de/0x320<br /> register_pernet_operations+0x2e4/0x750<br /> register_pernet_subsys+0x24/0x40<br /> tcf_register_action+0x9f/0x560<br /> do_one_initcall+0xf9/0x570<br /> do_init_module+0x190/0x650<br /> load_module+0x1fa5/0x23c0<br /> __do_sys_finit_module+0x10d/0x1b0<br /> do_syscall_64+0x58/0x80<br /> entry_SYSCALL_64_after_hwframe+0x72/0xdc<br /> RIP: 0033:0x7f42518f778d<br /> Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48<br /> 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 3d 01 f0 ff<br /> ff 73 01 c3 48 8b 0d cb 56 2c 00 f7 d8 64 89 01 48<br /> RSP: 002b:00007fff96869688 EFLAGS: 00000246 ORIG_RAX: 0000000000000139<br /> RAX: ffffffffffffffda RBX: 00005568ef7f7c90 RCX: 00007f42518f778d<br /> RDX: 0000000000000000 RSI: 00005568ef41d796 RDI: 0000000000000003<br /> RBP: 00005568ef41d796 R08: 0000000000000000 R09: 0000000000000000<br /> R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000<br /> R13: 00005568ef7f7d30 R14: 0000000000040000 R15: 0000000000000000<br /> <br /> <br /> This change addresses the issue by skipping the gen pointer<br /> de-reference in the mentioned error-path.<br /> <br /> Found by code inspection and verified with explicit error injection<br /> on a kasan-enabled kernel.