Look up another CVE · open CVE-2025-38246 in the interactive tracker
CVE-2025-38246
bnxt: properly flush XDP redirect lists
Published 2025-07-09 (15 months ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2025-38246 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | fixed | 6.12.37-1 | Update the kernel and reboot. Fixed in 6.12.37-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 6.12.37-1 | Update the kernel and reboot. Fixed in 6.12.37-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 6.12.37-1 | Update the kernel and reboot. Fixed in 6.12.37-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
We encountered following crash when testing a XDP_REDIRECT feature in production: [56251.579676] list_add corruption. next->prev should be prev (ffff93120dd40f30), but was ffffb301ef3a6740. (next=ffff93120dd 40f30). [56251.601413] ------------[ cut here ]------------ [56251.611357] kernel BUG at lib/list_debug.c:29! [56251.621082] Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [56251.632073] CPU: 111 UID: 0 PID: 0 Comm: swapper/111 Kdump: loaded Tainted: P O 6.12.33-cloudflare-2025.6. 3 #1 [56251.653155] Tainted: [P]=PROPRIETARY_MODULE, [O]=OOT_MODULE [56251.663877] Hardware name: MiTAC GC68B-B8032-G11P6-GPU/S8032GM-HE-CFR, BIOS V7.020.B10-sig 01/22/2025 [56251.682626] RIP: 0010:__list_add_valid_or_report+0x4b/0xa0 [56251.693203] Code: 0e 48 c7 c7 68 e7 d9 97 e8 42 16 fe ff 0f 0b 48 8b 52 08 48 39 c2 74 14 48 89 f1 48 c7 c7 90 e7 d9 97 48 89 c6 e8 25 16 fe ff <0f> 0b 4c 8b 02 49 39 f0 74 14 48 89 d1 48 c7 c7 e8 e7 d9 97 4c 89 [56251.725811] RSP: 0018:ffff93120dd40b80 EFLAGS: 00010246 [56251.736094] RAX: 0000000000000075 RBX: ffffb301e6bba9d8 RCX: 0000000000000000 [56251.748260] RDX: 0000000000000000 RSI: ffff9149afda0b80 RDI: ffff9149afda0b80 [56251.760349] RBP: ffff9131e49c8000 R08: 0000000000000000 R09: ffff93120dd40a18 [56251.772382] R10: ffff9159cf2ce1a8 R11: 0000000000000003 R12: ffff911a80850000 [56251.784364] R13: ffff93120fbc7000 R14: 0000000000000010 R15: ffff9139e7510e40 [56251.796278] FS: 0000000000000000(0000) GS:ffff9149afd80000(0000) knlGS:0000000000000000 [56251.809133] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [56251.819561] CR2: 00007f5e85e6f300 CR3: 00000038b85e2006 CR4: 0000000000770ef0 [56251.831365] PKRU: 55555554 [56251.838653] Call Trace: [56251.845560] <IRQ> [56251.851943] cpu_map_enqueue.cold+0x5/0xa [56251.860243] xdp_do_redirect+0x2d9/0x480 [56251.868388] bnxt_rx_xdp+0x1d8/0x4c0 [bnxt_en] [56251.877028] bnxt_rx_pkt+0x5f7/0x19b0 [bnxt_en] [56251.885665] ? cpu_max_write+0x1e/0x100 [56251.893510] ? srso_alias_return_thunk+0x5/0xfbef5 [56251.902276] __bnxt_poll_work+0x190/0x340 [bnxt_en] [56251.911058] bnxt_poll+0xab/0x1b0 [bnxt_en] [56251.919041] ? srso_alias_return_thunk+0x5/0xfbef5 [56251.927568] ? srso_alias_return_thunk+0x5/0xfbef5 [56251.935958] ? srso_alias_return_thunk+0x5/0xfbef5 [56251.944250] __napi_poll+0x2b/0x160 [56251.951155] bpf_trampoline_6442548651+0x79/0x123 [56251.959262] __napi_poll+0x5/0x160 [56251.966037] net_rx_action+0x3d2/0x880 [56251.973133] ? srso_alias_return_thunk+0x5/0xfbef5 [56251.981265] ? srso_alias_return_thunk+0x5/0xfbef5 [56251.989262] ? __hrtimer_run_queues+0x162/0x2a0 [56251.996967] ? srso_alias_return_thunk+0x5/0xfbef5 [56252.004875] ? srso_alias_return_thunk+0x5/0xfbef5 [56252.012673] ? bnxt_msix+0x62/0x70 [bnxt_en] [56252.019903] handle_softirqs+0xcf/0x270 [56252.026650] irq_exit_rcu+0x67/0x90 [56252.032933] common_interrupt+0x85/0xa0 [56252.039498] </IRQ> [56252.044246] <TASK> [56252.048935] asm_common_interrupt+0x26/0x40 [56252.055727] RIP: 0010:cpuidle_enter_state+0xb8/0x420 [56252.063305] Code: dc 01 00 00 e8 f9 79 3b ff e8 64 f7 ff ff 49 89 c5 0f 1f 44 00 00 31 ff e8 a5 32 3a ff 45 84 ff 0f 85 ae 01 00 00 fb 45 85 f6 <0f> 88 88 01 00 00 48 8b 04 24 49 63 ce 4c 89 ea 48 6b f1 68 48 29 [56252.088911] RSP: 0018:ffff93120c97fe98 EFLAGS: 00000202 [56252.096912] RAX: ffff9149afd80000 RBX: ffff9141d3a72800 RCX: 0000000000000000 [56252.106844] RDX: 00003329176c6b98 RSI: ffffffe36db3fdc7 RDI: 0000000000000000 [56252.116733] RBP: 0000000000000002 R08: 0000000000000002 R09: 000000000000004e [56252.126652] R10: ffff9149afdb30c4 R11: 071c71c71c71c71c R12: ffffffff985ff860 [56252.136637] R13: 00003329176c6b98 R14: 0000000000000002 R15: 0000000000000000 [56252.146667] ? cpuidle_enter_state+0xab/0x420 [56252.153909] cpuidle_enter+0x2d/0x40 [56252.160360] do_idle+0x176/0x1c0 [56252.166456 ---truncated---
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/net/ethernet/broadcom/bnxt/bnxt.c
- What this is
- BROADCOM BNXT_EN 50 GIGABIT ETHERNET DRIVERMAINTAINERS section matched on drivers/net/ethernet/broadcom/bnxt/ · netdev@vger.kernel.org · Maintained
- Kernel module
- bnxt_en
Check it on the machine
grep -wE 'CONFIG_BNXT|CONFIG_ETHERNET|CONFIG_NET_VENDOR_BROADCOM' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w bnxt_enPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi
- forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_BNXT, CONFIG_ETHERNET, CONFIG_NET_VENDOR_BROADCOM
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2025-07-09 (15 months ago)source
- CVSS
- 9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.34%, higher than 26.4% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/net
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 5.19 | 6.6.97 | 16254aa985d1 |
| 5.19 | 6.12.36 | c6665b8f0f58 |
| 5.19 | 6.15.5 | 02bf488d56df |
| 5.19 | 6.16 | 9caca6ac0e26 |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:NAttack vector, network
- The bug is triggered entirely by the mix of XDP verdicts produced for received network packets in a single NAPI poll, and those verdicts are decided from attacker-controlled packet headers. A remote unauthenticated attacker sending an interleaved packet stream to an internet-facing bnxt NIC reaches `bnxt_rx_xdp()` with no local access.
- AC:LAttack complexity, low
- In the relevant deployment (a native-mode XDP program on bnxt that uses both XDP_TX and XDP_REDIRECT — the standard L4LB/DDoS-mitigation pattern for this NIC class), the attacker fully controls both sides: they only need one redirected packet followed by one XDP_TX packet within the same 64-packet NAPI batch, which is trivial at line rate. The fix author states the crash reproduces stably by simply returning the two actions randomly.
- PR:NPrivileges required, none
- No authentication or privilege of any kind is needed — the attacker merely sends packets to the interface, and the vulnerable code runs in the NAPI receive path before any socket, credential, or namespace check.
- UI:NUser interaction, none
- Exploitation requires only inbound traffic processed by the driver's NAPI poll; no victim action is involved.
- S:UScope, unchanged
- The missed flush corrupts kernel list state and kernel stack memory within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.
- C:HConfidentiality impact, high
- The stale `bq->flush_node` dangles into a destroyed `net_rx_action()` stack frame, so subsequent list traversal in `__cpu_map_flush`/`__dev_flush` interprets reused kernel stack memory as `struct xdp_bulk_queue` and can feed those contents to `bq_xmit_all()` → `ndo_xdp_xmit`, transmitting kernel memory out a network interface; unflushed xdp_frames also reference page_pool pages that the driver has already recycled.
- I:HIntegrity impact, high
- `__list_del_clearprev()` on the stale node writes 8-byte kernel pointers through dangling `prev`/`next` addresses into a kernel stack frame that has since been reused for other execution, corrupting saved registers, locals, and potentially return addresses — a memory-corruption primitive with control-flow implications rather than a mere crash.
- A:HAvailability impact, high
- The defect produced a confirmed production kernel panic — `list_add corruption` → `kernel BUG at lib/list_debug.c:29` → invalid opcode oops in softirq/IRQ context on a 6.12 kernel, taking the machine down and requiring kdump.