CVE-2023-52610: In the Linux kernel, the following vulnerability has been resolved:net/sched: act_ct: fix skb leak and crash on ooo fragsact_ct adds skb->users before defragmentation. If frags arrive in order,the last frag's reference is reset in:  inet_frag_reasm_prepare    skb_morphwhich is not straightforward.However when frags arrive out of order, nobody unref the last frag, andall frags are leaked. The situation is even worse, as initiating packetcapture can lead to a crash[0] when skb has been cloned and shared at thesame time.Fix the issue by removing skb_get() before defragmentation. act_ctreturns TC_ACT_CONSUMED when defrag failed or in progress.[0]:[  843.804823] ------------[ cut here ]------------[  843.809659] kernel BUG at net/core/skbuff.c:2091![  843.814516] invalid opcode: 0000 [#1] PREEMPT SMP[  843.819296] CPU: 7 PID: 0 Comm: swapper/7 Kdump: loaded Tainted: G S 6.7.0-rc3 #2[  843.824107] Hardware name: XFUSION 1288H V6/BC13MBSBD, BIOS 1.29 11/25/2022[  843.828953] RIP: 0010:pskb_expand_head+0x2ac/0x300[  843.833805] Code: 8b 70 28 48 85 f6 74 82 48 83 c6 08 bf 01 00 00 00 e8 38 bd ff ff 8b 83 c0 00 00 00 48 03 83 c8 00 00 00 e9 62 ff ff ff 0f 0b <0f> 0b e8 8d d0 ff ff e9 b3 fd ff ff 81 7c 24 14 40 01 00 00 4c 89[  843.843698] RSP: 0018:ffffc9000cce07c0 EFLAGS: 00010202[  843.848524] RAX: 0000000000000002 RBX: ffff88811a211d00 RCX: 0000000000000820[  843.853299] RDX: 0000000000000640 RSI: 0000000000000000 RDI: ffff88811a211d00[  843.857974] RBP: ffff888127d39518 R08: 00000000bee97314 R09: 0000000000000000[  843.862584] R10: 0000000000000000 R11: ffff8881109f0000 R12: 0000000000000880[  843.867147] R13: ffff888127d39580 R14: 0000000000000640 R15: ffff888170f7b900[  843.871680] FS:  0000000000000000(0000) GS:ffff889ffffc0000(0000) knlGS:0000000000000000[  843.876242] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033[  843.880778] CR2: 00007fa42affcfb8 CR3: 000000011433a002 CR4: 0000000000770ef0[  843.885336] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000[  843.889809] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400[  843.894229] PKRU: 55555554[  843.898539] Call Trace:[  843.902772]  <IRQ>[  843.906922]  ? __die_body+0x1e/0x60[  843.911032]  ? die+0x3c/0x60[  843.915037]  ? do_trap+0xe2/0x110[  843.918911]  ? pskb_expand_head+0x2ac/0x300[  843.922687]  ? do_error_trap+0x65/0x80[  843.926342]  ? pskb_expand_head+0x2ac/0x300[  843.929905]  ? exc_invalid_op+0x50/0x60[  843.933398]  ? pskb_expand_head+0x2ac/0x300[  843.936835]  ? asm_exc_invalid_op+0x1a/0x20[  843.940226]  ? pskb_expand_head+0x2ac/0x300[  843.943580]  inet_frag_reasm_prepare+0xd1/0x240[  843.946904]  ip_defrag+0x5d4/0x870[  843.950132]  nf_ct_handle_fragments+0xec/0x130 [nf_conntrack][  843.953334]  tcf_ct_act+0x252/0xd90 [act_ct][  843.956473]  ? tcf_mirred_act+0x516/0x5a0 [act_mirred][  843.959657]  tcf_action_exec+0xa1/0x160[  843.962823]  fl_classify+0x1db/0x1f0 [cls_flower][  843.966010]  ? skb_clone+0x53/0xc0[  843.969173]  tcf_classify+0x24d/0x420[  843.972333]  tc_run+0x8f/0xf0[  843.975465]  __netif_receive_skb_core+0x67a/0x1080[  843.978634]  ? dev_gro_receive+0x249/0x730[  843.981759]  __netif_receive_skb_list_core+0x12d/0x260[  843.984869]  netif_receive_skb_list_internal+0x1cb/0x2f0[  843.987957]  ? mlx5e_handle_rx_cqe_mpwrq_rep+0xfa/0x1a0 [mlx5_core][  843.991170]  napi_complete_done+0x72/0x1a0[  843.994305]  mlx5e_napi_poll+0x28c/0x6d0 [mlx5_core][  843.997501]  __napi_poll+0x25/0x1b0[  844.000627]  net_rx_action+0x256/0x330[  844.003705]  __do_softirq+0xb3/0x29b[  844.006718]  irq_exit_rcu+0x9e/0xc0[  844.009672]  common_interrupt+0x86/0xa0[  844.012537]  </IRQ>[  844.015285]  <TASK>[  844.017937]  asm_common_interrupt+0x26/0x40[  844.020591] RIP: 0010:acpi_safe_halt+0x1b/0x20[  844.023247] Code: ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 65 48 8b 04 25 00 18 03 00 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 81 d0 44 00 fb---truncated---
Key phrases: skb leak, crash