CVE-2024-56658

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net: defer final &amp;#39;struct net&amp;#39; free in netns dismantle<br /> <br /> Ilya reported a slab-use-after-free in dst_destroy [1]<br /> <br /> Issue is in xfrm6_net_init() and xfrm4_net_init() :<br /> <br /> They copy xfrm[46]_dst_ops_template into net-&gt;xfrm.xfrm[46]_dst_ops.<br /> <br /> But net structure might be freed before all the dst callbacks are<br /> called. So when dst_destroy() calls later :<br /> <br /> if (dst-&gt;ops-&gt;destroy)<br /> dst-&gt;ops-&gt;destroy(dst);<br /> <br /> dst-&gt;ops points to the old net-&gt;xfrm.xfrm[46]_dst_ops, which has been freed.<br /> <br /> See a relevant issue fixed in :<br /> <br /> ac888d58869b ("net: do not delay dst_entries_add() in dst_release()")<br /> <br /> A fix is to queue the &amp;#39;struct net&amp;#39; to be freed after one<br /> another cleanup_net() round (and existing rcu_barrier())<br /> <br /> [1]<br /> <br /> BUG: KASAN: slab-use-after-free in dst_destroy (net/core/dst.c:112)<br /> Read of size 8 at addr ffff8882137ccab0 by task swapper/37/0<br /> Dec 03 05:46:18 kernel:<br /> CPU: 37 UID: 0 PID: 0 Comm: swapper/37 Kdump: loaded Not tainted 6.12.0 #67<br /> Hardware name: Red Hat KVM/RHEL, BIOS 1.16.1-1.el9 04/01/2014<br /> Call Trace:<br /> <br /> dump_stack_lvl (lib/dump_stack.c:124)<br /> print_address_description.constprop.0 (mm/kasan/report.c:378)<br /> ? dst_destroy (net/core/dst.c:112)<br /> print_report (mm/kasan/report.c:489)<br /> ? dst_destroy (net/core/dst.c:112)<br /> ? kasan_addr_to_slab (mm/kasan/common.c:37)<br /> kasan_report (mm/kasan/report.c:603)<br /> ? dst_destroy (net/core/dst.c:112)<br /> ? rcu_do_batch (kernel/rcu/tree.c:2567)<br /> dst_destroy (net/core/dst.c:112)<br /> rcu_do_batch (kernel/rcu/tree.c:2567)<br /> ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2491)<br /> ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4339 kernel/locking/lockdep.c:4406)<br /> rcu_core (kernel/rcu/tree.c:2825)<br /> handle_softirqs (kernel/softirq.c:554)<br /> __irq_exit_rcu (kernel/softirq.c:589 kernel/softirq.c:428 kernel/softirq.c:637)<br /> irq_exit_rcu (kernel/softirq.c:651)<br /> sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049)<br /> <br /> <br /> asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702)<br /> RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/kernel/process.c:743)<br /> Code: 00 4d 29 c8 4c 01 c7 4c 29 c2 e9 6e ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 0f 00 2d c7 c9 27 00 fb f4 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90<br /> RSP: 0018:ffff888100d2fe00 EFLAGS: 00000246<br /> RAX: 00000000001870ed RBX: 1ffff110201a5fc2 RCX: ffffffffb61a3e46<br /> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffb3d4d123<br /> RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed11c7e1835d<br /> R10: ffff888e3f0c1aeb R11: 0000000000000000 R12: 0000000000000000<br /> R13: ffff888100d20000 R14: dffffc0000000000 R15: 0000000000000000<br /> ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:148)<br /> ? cpuidle_idle_call (kernel/sched/idle.c:186)<br /> default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118)<br /> cpuidle_idle_call (kernel/sched/idle.c:186)<br /> ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168)<br /> ? lock_release (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5848)<br /> ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)<br /> ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59)<br /> do_idle (kernel/sched/idle.c:326)<br /> cpu_startup_entry (kernel/sched/idle.c:423 (discriminator 1))<br /> start_secondary (arch/x86/kernel/smpboot.c:202 arch/x86/kernel/smpboot.c:282)<br /> ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:232)<br /> ? soft_restart_cpu (arch/x86/kernel/head_64.S:452)<br /> common_startup_64 (arch/x86/kernel/head_64.S:414)<br /> <br /> Dec 03 05:46:18 kernel:<br /> Allocated by task 12184:<br /> kasan_save_stack (mm/kasan/common.c:48)<br /> kasan_save_track (./arch/x86/include/asm/current.h:49 mm/kasan/common.c:60 mm/kasan/common.c:69)<br /> __kasan_slab_alloc (mm/kasan/common.c:319 mm/kasan/common.c:345)<br /> kmem_cache_alloc_noprof (mm/slub.c:4085 mm/slub.c:4134 mm/slub.c:4141)<br /> copy_net_ns (net/core/net_namespace.c:421 net/core/net_namespace.c:480)<br /> create_new_namespaces<br /> ---truncated---