CVE-2024-56719: net: stmmac: fix TSO DMA API usage causing oops

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-12-29 · updated 2026-10-15

Description

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix TSO DMA API usage causing oops Commit 66600fac7a98 ("net: stmmac: TSO: Fix unbalanced DMA map/unmap for non-paged SKB data") moved the assignment of tx_skbuff_dma[]'s members to be later in stmmac_tso_xmit(). The buf (dma cookie) and len stored in this structure are passed to dma_unmap_single() by stmmac_tx_clean(). The DMA API requires that the dma cookie passed to dma_unmap_single() is the same as the value returned from dma_map_single(). However, by moving the assignment later, this is not the case when priv->dma_cap.addr64 > 32 as "des" is offset by proto_hdr_len. This causes problems such as: dwc-eth-dwmac 2490000.ethernet eth0: Tx DMA map failed and with DMA_API_DEBUG enabled: DMA-API: dwc-eth-dwmac 2490000.ethernet: device driver tries to +free DMA memory it has not allocated [device address=0x000000ffffcf65c0] [size=66 bytes] Fix this by maintaining "des" as the original DMA cookie, and use tso_des to pass the offset DMA cookie to stmmac_tso_allocator(). Full details of the crashes can be found at: https://lore.kernel.org/all/d8112193-0386-4e14-b516-37c2d838171a@nvidia.com/ https://lore.kernel.org/all/klkzp5yn5kq5efgtrow6wbvnc46bcqfxs65nz3qy77ujr5turc@bwwhelz2l4dw/

Affected products

Linux kernel: from 5.15.171 before 5.16; from 6.1.116 before 6.2; from 6.6.60 before 6.6.68; from 6.11.7 before 6.12.7; 6.13-rc1, 6.13-rc2 — fixed in 5.16, 6.12.7, 6.2, 6.6.68

How to fix

Upgrade to a fixed version: Linux kernel 5.16, 6.12.7, 6.2, 6.6.68. Check the vendor advisory for mitigations.

References

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