Hello, We have a security solution which intercepts network traffic for inspection using a combination of Transparent Proxy Provider and Content filter. Lately we are seeing reports from the market that on M5 Macbooks and A18 Neos the system will kernel panic using our solution, even though it never happens on M1-M4 and no significant code changes were made in the mean time. All crashes seem to be related to an internal double free in the kernel: panic(cpu 0 caller 0xfffffe003bb68224): skmem_slab_free_locked: attempt to free invalid or already-freed obj 0xf2fffe29e15f2400 on skm 0xf6fffe2518aaa200 @skmem_slab.c:646 Debugger message: panic Memory ID: 0xff OS release type: User OS version: 25D2128 Kernel version: Darwin Kernel Version 25.3.0: Wed Jan 28 20:54:38 PST 2026; root:xnu-12377.91.3~2/RELEASE_ARM64_T6050 Additionally, from further log inspection, before panics we find some weird kernel messages which seem to be related to some DMA operations gone wrong in the network driver on some machines: 2026-03-30 14:11:21.779124+0300 0x30f2 Default 0x0 873 0 Arc: (Network) [com.apple.network:connection] [C9.1.1.1 IPv4#e5b4bb04:443 in_progress socket-flow (satisfied (Path is satisfied), interface: en0[802.11], ipv4, ipv6, dns, uses wifi, flow divert agg: 1, LQM: good)] event: flow:start_connect @0.075s 2026-03-30 14:11:21.780015+0300 0x1894 Default 0x0 0 0 kernel: (402262746): No more valid control units, disabling flow divert 2026-03-30 14:11:21.780017+0300 0x1894 Default 0x0 0 0 kernel: (402262746): Skipped all flow divert services, disabling flow divert 2026-03-30 14:11:21.780102+0300 0x1894 Default 0x0 0 0 kernel: SK[2]: flow_entry_alloc fe "0 proc kernel_task(0)Arc nx_port 1 flow_uuid D46E230E-B826-4E0A-8C59-4C4C8BF6AA60 flags 0x14120<CONNECTED,QOS_MARKING,EXT_PORT,EXT_FLOWID> ipver=4,src=<IPv4-redacted>.49703,dst=<IPv4-redacted>.443,proto=0x06 mask=0x0000003f,hash=0x04e0a750 tp_proto=0x06" 2026-03-30 14:11:21.780194+0300 0x1894 Default 0x0 0 0 kernel: tcp connect outgoing: [<IPv4-redacted>:49703<-><IPv4-redacted>:443] interface: en0 (skipped: 0) so_gencnt: 14634 t_state: SYN_SENT process: Arc:873 SYN in/out: 0/1 bytes in/out: 0/0 pkts in/out: 0/0 rtt: 0.0 ms rttvar: 250.0 ms base_rtt: 0 ms error: 0 so_error: 0 svc/tc: 0 flow: 0x9878386f 2026-03-30 14:11:21.934431+0300 0xed Default 0x0 0 0 kernel: Hit error condition (not panicking as we're in error handler): t8110dart <private> (dart-apcie0): invalid SID 2 TTBR access: level 1 table_index 0 page_offset 0x2 2026-03-30 14:11:21.934432+0300 0xed Default 0x0 0 0 kernel: [ 73.511690]: arm_cpu_init(): cpu 6 online 2026-03-30 14:11:21.934441+0300 0xed Default 0x0 0 0 kernel: [ 73.511696]: arm_cpu_init(): cpu 9 online 2026-03-30 14:11:21.934441+0300 0xed Default 0x0 0 0 kernel: [ 73.569033]: arm_cpu_init(): cpu 6 online 2026-03-30 14:11:21.934441+0300 0xed Default 0x0 0 0 kernel: [ 73.569038]: arm_cpu_init(): cpu 9 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.577453]: arm_cpu_init(): cpu 7 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.586328]: arm_cpu_init(): cpu 5 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.586332]: arm_cpu_init(): cpu 8 online 2026-03-30 14:11:21.934442+0300 0xed Default 0x0 0 0 kernel: [ 73.621392]: (dart-apcie0) AppleT8110DART::_fatalException: dart-apcie0 (<ptr>): DART DART SID exception ERROR_SID_SUMMARY 0x00003000 ERROR_ADDRESS 0x0000000000009800 2026-03-30 14:11:21.934443+0300 0xed Default 0x0 0 0 kernel: [ 73.621397]: Hit error condition (not panicking as we're in error handler): 2026-03-30 14:11:21.934443+0300 0xed Default 0x0 0 0 kernel: t8110dart <ptr> (dart-apcie0): invalid SID 2 TTBR access: level 1 table_index 0 page_offset 0x2Expect a `deadbeef` in the error messages below 2026-03-30 14:11:21.934452+0300 0xed Default 0x0 0 0 kernel: Expect a `deadbeef` in the error messages below 2026-03-30 14:11:21.934456+0300 0xed Default 0x0 0 0 kernel: (AppleEmbeddedPCIE) apcie[0:centauri-control]::_dartErrorHandler() InvalidPTE caused by read from address 0x9800 by SID 2 (RID 2:0:1/useCount 1/device <private>) 2026-03-30 14:11:21.934469+0300 0xed Default 0x0 0 0 kernel: (AppleT8110DART) Ignored dart-apcie0 (0xfbfffe18820b0000): DART(DART) error: SID 2 PTE invalid exception on read of DVA 0x9800 (SEG 0 PTE 0x2) ERROR_SID_SUMMARY 0x00003000 TIME 0x11242d43fd TTE 0xffffffffffffffff AXI_ID 0 We do not have any correlation between machines, usage pattern or installed applications. Uninstalling the network protection features seem to largely fix the issues, even though we have heard of crashes happening even in safe mode or with our network extension disabled from system settings. We weren't able to reproduce internally and it seems to happen completely random on client machines, but often enough to be disrupting. Can you tell us please if this is a known problem and if there's a workaround or what can we do to narrow it down? Thanks.

Hello, We are developing a content filter solution which includes both a content filter and a packet filter (NEFilterControlProvider and NEFilterPacketProvider). We've observed that if the packet filter is enabled (both by itself or in conjunction with the content filter) we are having issues with bridged thunderbolt connections - traffic on that interface stops in both directions. We've tested on bridges to other MacOS devices or Windows devices, but both exhibit the same behavior. Even if the packet provider is reduces to "allow all" in the callback the issue remains. Our handler is not called at all anyway so we can't allow or deny packets. We've tested this on Macos 15 and 26 but it behaves the same. If we only enable the NEFilterControlProvider everything works fine. All other types of network interfaces work fine as well. Is this a known issue? Is there an workaround? Thanks.