CVE-2026-53033

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> bpf, sockmap: Take state lock for af_unix iter<br /> <br /> When a BPF iterator program updates a sockmap, there is a race condition in<br /> unix_stream_bpf_update_proto() where the `peer` pointer can become stale[1]<br /> during a state transition TCP_ESTABLISHED -&gt; TCP_CLOSE.<br /> <br /> CPU0 bpf CPU1 close<br /> -------- ----------<br /> // unix_stream_bpf_update_proto()<br /> sk_pair = unix_peer(sk)<br /> if (unlikely(!sk_pair))<br /> return -EINVAL;<br /> // unix_release_sock()<br /> skpair = unix_peer(sk);<br /> unix_peer(sk) = NULL;<br /> sock_put(skpair)<br /> sock_hold(sk_pair) // UaF<br /> <br /> More practically, this fix guarantees that the iterator program is<br /> consistently provided with a unix socket that remains stable during<br /> iterator execution.<br /> <br /> [1]:<br /> BUG: KASAN: slab-use-after-free in unix_stream_bpf_update_proto+0x155/0x490<br /> Write of size 4 at addr ffff8881178c9a00 by task test_progs/2231<br /> Call Trace:<br /> dump_stack_lvl+0x5d/0x80<br /> print_report+0x170/0x4f3<br /> kasan_report+0xe4/0x1c0<br /> kasan_check_range+0x125/0x200<br /> unix_stream_bpf_update_proto+0x155/0x490<br /> sock_map_link+0x71c/0xec0<br /> sock_map_update_common+0xbc/0x600<br /> sock_map_update_elem+0x19a/0x1f0<br /> bpf_prog_bbbf56096cdd4f01_selective_dump_unix+0x20c/0x217<br /> bpf_iter_run_prog+0x21e/0xae0<br /> bpf_iter_unix_seq_show+0x1e0/0x2a0<br /> bpf_seq_read+0x42c/0x10d0<br /> vfs_read+0x171/0xb20<br /> ksys_read+0xff/0x200<br /> do_syscall_64+0xf7/0x5e0<br /> entry_SYSCALL_64_after_hwframe+0x76/0x7e<br /> <br /> Allocated by task 2236:<br /> kasan_save_stack+0x30/0x50<br /> kasan_save_track+0x14/0x30<br /> __kasan_slab_alloc+0x63/0x80<br /> kmem_cache_alloc_noprof+0x1d5/0x680<br /> sk_prot_alloc+0x59/0x210<br /> sk_alloc+0x34/0x470<br /> unix_create1+0x86/0x8a0<br /> unix_stream_connect+0x318/0x15b0<br /> __sys_connect+0xfd/0x130<br /> __x64_sys_connect+0x72/0xd0<br /> do_syscall_64+0xf7/0x5e0<br /> entry_SYSCALL_64_after_hwframe+0x76/0x7e<br /> <br /> Freed by task 2236:<br /> kasan_save_stack+0x30/0x50<br /> kasan_save_track+0x14/0x30<br /> kasan_save_free_info+0x3b/0x70<br /> __kasan_slab_free+0x47/0x70<br /> kmem_cache_free+0x11c/0x590<br /> __sk_destruct+0x432/0x6e0<br /> unix_release_sock+0x9b3/0xf60<br /> unix_release+0x8a/0xf0<br /> __sock_release+0xb0/0x270<br /> sock_close+0x18/0x20<br /> __fput+0x36e/0xac0<br /> fput_close_sync+0xe5/0x1a0<br /> __x64_sys_close+0x7d/0xd0<br /> do_syscall_64+0xf7/0x5e0<br /> entry_SYSCALL_64_after_hwframe+0x76/0x7e