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CVE-2026-93796
wifi: iwlwifi: pcie: null RX pointers after free
Published 2026-09-24 (24 days 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-2026-93796 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 | fixedDSA-6528-1 · 2026-09-29 · text | 6.12.111-1 | Update the kernel and reboot. DSA-6528-1 shipped the fix on 2026-09-29, in 6.12.111-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4817-1 · 2026-10-04 · text | 6.12.111-1~deb12u1 | Update the kernel and reboot. DLA-4817-1 shipped the fix on 2026-10-04, in 6.12.111-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
When iwl_pcie_tx_init() fails after RX init, nic init unwinds via iwl_pcie_rx_free(). The freed RX members stayed non-NULL on the live transport object, so later teardown or retry could touch stale RX state. Set rx_pool, global_table, rxq, and alloc_page to NULL after free to make repeated cleanup and retry paths safe.
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/wireless/intel/iwlwifi/pcie/gen1_2/rx.c
- What this is
- INTEL WIRELESS WIFI LINK (iwlwifi)MAINTAINERS section matched on drivers/net/wireless/intel/iwlwifi/ · linux-wireless@vger.kernel.org · Supported
Show whether Debian builds this, per release
Not established. This site could not find the build rule for the affected file in the kernel trees Debian ships, so it has no answer about whether Debian compiles this code. Read that as unknown, never as absent.
- bookworm, trixie, forky, sid, bookworm · linux-6.12?
- ?
- not established - no Makefile entry for the affected file
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
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
Signals
- Published
- 2026-09-24 (24 days ago)source
- CVSS
- 7.0 high
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.12%, higher than 1.7% 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 |
|---|---|---|
| 5.12 | 6.12.111 | 6ec5bf430cf7 |
| 5.12 | 6.18.53 | 3456c5bcc987 |
| 5.12 | 7.2 | 2c79d7a7b583 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4817-1 | 2026-10-04 | bookworm 6.12.111-1~deb12u1 | tracker |
| DSA-6528-1 | 2026-09-29 | trixie 6.12.111-1 | tracker |
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:LAttack vector, local
- The dangling pointers are created in iwl_pcie_rx_free() when iwl_pcie_nic_init() unwinds a failed iwl_pcie_tx_init() after iwl_pcie_rx_init(). That runs from iwl_trans_pcie_start_fw() during iwl_mvm_start_get_nvm()/iwl_mvm_up() (PCI firmware callback or mac80211 drv_start), not from iwl_pcie_rx_handle() or any 802.11 frame parse.
- AC:HAttack complexity, high
- iwl_pcie_nic_init() only calls iwl_pcie_rx_free() when iwl_pcie_tx_init() fails after a successful iwl_pcie_rx_init(). Reachable failures are ENOMEM in iwl_pcie_tx_alloc() or a non-power-of-two slots_num in iwl_queue_init(); the attacker cannot make RX allocation succeed and the subsequent TX allocation fail on demand.
- PR:LPrivileges required, low
- iwl_op_mode_mvm_start() calls iwl_mvm_start_get_nvm() → iwl_run_init_mvm_ucode() → iwl_trans_start_fw() with no capable() check from iwl_req_fw_callback after PCI bind. A local unprivileged process on a host with iwlwifi is sufficient; init-namespace CAP_NET_ADMIN is not required to reach this unwind.
- UI:NUser interaction, none
- After iwl_pcie_rx_free() in the nic_init unwind, iwl_mvm_start_get_nvm() always calls iwl_mvm_stop_device() (and iwl_run_init_ucode() always calls iwl_trans_stop_device()), so iwl_pcie_rx_napi_sync() uses the stale rxq with no victim mount, file open, or association.
- S:UScope, unchanged
- The UAF and double-free of trans_pcie->rxq, rx_pool, global_table, and alloc_page stay inside the host iwlwifi PCIe transport on the same kernel authority; this is not a KVM/Xen guest-to-host escape or an IOMMU/DMA bypass.
- C:HConfidentiality impact, high
- iwl_pcie_rx_free() kfree()s rxq/rx_pool/global_table and __free_pages()s alloc_page without NULL, then iwl_pcie_rx_napi_sync() and _iwl_pcie_rx_init() dereference those freed objects; UAF of those slabs/pages enables arbitrary kernel read.
- I:HIntegrity impact, high
- _iwl_pcie_rx_init() writes the dangling rxq/rx_pool/global_table (list restock, netif_napi_add), and a later iwl_pcie_rx_free() from iwl_trans_pcie_free() double-frees the same kmalloc objects, giving a heap write/control-flow primitive.
- A:HAvailability impact, high
- iwl_pcie_rx_napi_sync() walking a kfree'd rxq, or a second iwl_pcie_rx_free() of the same pointers from iwl_trans_pcie_free(), is a kernel oops or panic.