CVE-2023-54004CVE-2023-54004

In the Linux kernel, the following vulnerability has been resolved: udplite: Fix NULL pointer dereference in __sk_mem_raise_allocated(). syzbot reported [0] a null-ptr-deref in sk_get_rmem0() while using IPPROTO_UDPLITE (0x88): 14:25:52 executing program 1: r0 = socket$inet6(0xa, 0x80002, 0x88) We had a similar report [1] for probably sk_memory_allocated_add() in __sk_mem_raise_allocated(), and commit c915fe13cbaa ("udplite: fix NULL pointer dereference") fixed it by setting .memory_allocated for udplite_prot and udplitev6_prot. To fix the variant, we need to set either .sysctl_wmem_offset or .sysctl_rmem. Now UDP and UDPLITE share the same value for .memory_allocated, so we use the same .sysctl_wmem_offset for UDP and UDPLITE. [0]: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 6829 Comm: syz-executor.1 Not tainted 6.4.0-rc2-syzkal