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CVE-2026-97570
bnxt_en: Bound SW TPA IDs to prevent crashes
Published 2026-09-25 (24 days ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-97570 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 | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| Debian 14forky | fixed | 7.2.7-1 | Update the kernel and reboot. Fixed in 7.2.7-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.7-1 | Update the kernel and reboot. Fixed in 7.2.7-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
FW supports up to 1024 concurrent TPAs, so the FW TPA ID is in the range 0..1023 (see commit ec4d8e7cf024 ("bnxt_en: Add TPA ID mapping logic for 57500 chips.")). bnxt_alloc_agg_idx is intended to wrap the FW ID down to a software ID which is used to index rxr->rx_tpa, and to generate a mapping between FW IDs and the wrapped software ID. On a 57608 with firmware version 233, the firmware advertises 32 concurrent TPAs. As of the commit under fixes, bp->max_tpa on this NIC is set to 32. If the software ID from bnxt_alloc_agg_idx is above 31, this results in an invalid address being loaded on this line: tpa_info = &rxr->rx_tpa[agg_id]; because rx_tpa is allocated with only bp->max_tpa (32) entries. Writes to tpa_info later in the code are out of bounds. This bug results in a crash at boot: Oops: general protection fault, kernel NULL pointer dereference 0x8: 0000 [#1] SMP NOPTI RIP: 0010:bnxt_rx_pkt+0xc0/0x1560 RSP: 0018:ffffc900009b8c78 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000048 RCX: 0000000206682516 RDX: ffffc900009b8db4 RSI: 0000000000000000 RDI: 01ffffff038fe1c0 RBP: ffffc9006e687480 R08: ffffc9006e687000 R09: 0000000000003048 R10: 0000000000000480 R11: ffff8881c6083900 R12: 0000000006682516 R13: ffff8881c6095400 R14: 0000000000000016 R15: ffff8881c6b66680 FS: 0000000000000000(0000) GS:ffff88fef3c77000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc8bda40584 CR3: 000000807c812001 CR4: 0000000008772ef0 PKRU: 55555554 Call Trace: <IRQ> ? __netif_receive_skb_list_core+0x1ca/0x250 __bnxt_poll_work+0x152/0x280 bnxt_poll_p5+0x1cd/0x480 __napi_poll+0x30/0x180 net_rx_action+0x20b/0x3b0 ? note_gp_changes+0x53/0xe0 ? tick_setup_sched_timer+0x180/0x180 ? __napi_schedule+0x9a/0xb0 ? bnxt_msix+0x24/0x30 handle_softirqs+0xdd/0x2c0 __irq_exit_rcu.llvm.3171231171502365008+0x47/0xf0 common_interrupt+0x85/0x90 </IRQ> <TASK> asm_common_interrupt+0x22/0x40 This stack trace is from a crash triggered when an out of bounds rx_tpa is dereferenced. The invalid write mentioned above is silent in this particular crash. Fix this by allocating rx_tpa with bp->max_tpa rounded up to the next power of 2 (bp->max_tpa_roundup_size) entries and masking the FW TPA ID with that size, so the wrapped ID can never index past the end of the array.
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
drivers/net/ethernet/broadcom/bnxt/bnxt.h
- 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
- 2026-09-25 (24 days ago)source
- CVSS
- 8.1 high
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.44%, higher than 37.1% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- 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 |
|---|---|---|
| 7.1 | 7.2.7 | 05cf64d17177 |
| 7.1 | 7.3 | c0aceaf65b70 |
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
- bnxt_tpa_start() runs from bnxt_rx_pkt()/__bnxt_poll_work() in NAPI when the NIC opens a TPA aggregation for received TCP segments, so a remote sender of TCP traffic drives the out-of-bounds rx_tpa[agg_id] access with no local access needed.
- AC:HAttack complexity, high
- It needs a P7 NIC (e.g. 57608) whose firmware advertises max_aggs_supported <= 32 so max_tpa stays small. The firmware, not the attacker, picks TPA_START_AGG_ID_P5; a masked ID of 32-255 then overruns rx_tpa. The attacker controls neither the hardware/firmware nor the ID choice.
- PR:NPrivileges required, none
- The path runs in the RX softirq on arriving TCP segments before any socket or authentication processing, so the sender needs no credentials.
- UI:NUser interaction, none
- No victim action is needed; normal packet reception on the bnxt interface with hardware GRO/TPA enabled reaches bnxt_tpa_start().
- S:UScope, unchanged
- The corruption is in kernel heap memory next to the kzalloc'ed rx_tpa array in the same kernel authority; no guest/host or IOMMU boundary is shown to be crossed.
- C:HConfidentiality impact, high
- bnxt_tpa_start() reads data/data_ptr/mapping from an out-of-bounds bnxt_tpa_info and posts that mapping to the RX descriptor (rx_bd_haddr), so stale heap contents get handed to the NIC and later to skb construction, exposing out-of-bounds kernel memory.
- I:HIntegrity impact, high
- It writes buffer pointers, the DMA mapping, and packet-derived len/rss_hash/flags2/hdr_info past the end of rx_tpa, and has the NIC DMA received packet bytes to a stale mapping read from out-of-bounds memory; this is heap memory corruption.
- A:HAvailability impact, high
- The commit's reproduction shows a general protection fault oops in bnxt_rx_pkt in IRQ context during boot under normal RX traffic, which takes the machine down.