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]
No PoCs from references.
- https://github.com/NaInSec/CVE-LIST