ghsa-wp26-g22c-7r5j
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: TSO: Fix unbalanced DMA map/unmap for non-paged SKB data
In case the non-paged data of a SKB carries protocol header and protocol payload to be transmitted on a certain platform that the DMA AXI address width is configured to 40-bit/48-bit, or the size of the non-paged data is bigger than TSO_MAX_BUFF_SIZE on a certain platform that the DMA AXI address width is configured to 32-bit, then this SKB requires at least two DMA transmit descriptors to serve it.
For example, three descriptors are allocated to split one DMA buffer mapped from one piece of non-paged data: dma_desc[N + 0], dma_desc[N + 1], dma_desc[N + 2]. Then three elements of tx_q->tx_skbuff_dma[] will be allocated to hold extra information to be reused in stmmac_tx_clean(): tx_q->tx_skbuff_dma[N + 0], tx_q->tx_skbuff_dma[N + 1], tx_q->tx_skbuff_dma[N + 2]. Now we focus on tx_q->tx_skbuff_dma[entry].buf, which is the DMA buffer address returned by DMA mapping call. stmmac_tx_clean() will try to unmap the DMA buffer ONLY_IF tx_q->tx_skbuff_dma[entry].buf is a valid buffer address.
The expected behavior that saves DMA buffer address of this non-paged data to tx_q->tx_skbuff_dma[entry].buf is: tx_q->tx_skbuff_dma[N + 0].buf = NULL; tx_q->tx_skbuff_dma[N + 1].buf = NULL; tx_q->tx_skbuff_dma[N + 2].buf = dma_map_single(); Unfortunately, the current code misbehaves like this: tx_q->tx_skbuff_dma[N + 0].buf = dma_map_single(); tx_q->tx_skbuff_dma[N + 1].buf = NULL; tx_q->tx_skbuff_dma[N + 2].buf = NULL;
On the stmmac_tx_clean() side, when dma_desc[N + 0] is closed by the DMA engine, tx_q->tx_skbuff_dma[N + 0].buf is a valid buffer address obviously, then the DMA buffer will be unmapped immediately. There may be a rare case that the DMA engine does not finish the pending dma_desc[N + 1], dma_desc[N + 2] yet. Now things will go horribly wrong, DMA is going to access a unmapped/unreferenced memory region, corrupted data will be transmited or iommu fault will be triggered :(
In contrast, the for-loop that maps SKB fragments behaves perfectly as expected, and that is how the driver should do for both non-paged data and paged frags actually.
This patch corrects DMA map/unmap sequences by fixing the array index for tx_q->tx_skbuff_dma[entry].buf when assigning DMA buffer address.
Tested and verified on DWXGMAC CORE 3.20a
{
"affected": [],
"aliases": [
"CVE-2024-53058"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-11-19T18:15:25Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: stmmac: TSO: Fix unbalanced DMA map/unmap for non-paged SKB data\n\nIn case the non-paged data of a SKB carries protocol header and protocol\npayload to be transmitted on a certain platform that the DMA AXI address\nwidth is configured to 40-bit/48-bit, or the size of the non-paged data\nis bigger than TSO_MAX_BUFF_SIZE on a certain platform that the DMA AXI\naddress width is configured to 32-bit, then this SKB requires at least\ntwo DMA transmit descriptors to serve it.\n\nFor example, three descriptors are allocated to split one DMA buffer\nmapped from one piece of non-paged data:\n dma_desc[N + 0],\n dma_desc[N + 1],\n dma_desc[N + 2].\nThen three elements of tx_q-\u003etx_skbuff_dma[] will be allocated to hold\nextra information to be reused in stmmac_tx_clean():\n tx_q-\u003etx_skbuff_dma[N + 0],\n tx_q-\u003etx_skbuff_dma[N + 1],\n tx_q-\u003etx_skbuff_dma[N + 2].\nNow we focus on tx_q-\u003etx_skbuff_dma[entry].buf, which is the DMA buffer\naddress returned by DMA mapping call. stmmac_tx_clean() will try to\nunmap the DMA buffer _ONLY_IF_ tx_q-\u003etx_skbuff_dma[entry].buf\nis a valid buffer address.\n\nThe expected behavior that saves DMA buffer address of this non-paged\ndata to tx_q-\u003etx_skbuff_dma[entry].buf is:\n tx_q-\u003etx_skbuff_dma[N + 0].buf = NULL;\n tx_q-\u003etx_skbuff_dma[N + 1].buf = NULL;\n tx_q-\u003etx_skbuff_dma[N + 2].buf = dma_map_single();\nUnfortunately, the current code misbehaves like this:\n tx_q-\u003etx_skbuff_dma[N + 0].buf = dma_map_single();\n tx_q-\u003etx_skbuff_dma[N + 1].buf = NULL;\n tx_q-\u003etx_skbuff_dma[N + 2].buf = NULL;\n\nOn the stmmac_tx_clean() side, when dma_desc[N + 0] is closed by the\nDMA engine, tx_q-\u003etx_skbuff_dma[N + 0].buf is a valid buffer address\nobviously, then the DMA buffer will be unmapped immediately.\nThere may be a rare case that the DMA engine does not finish the\npending dma_desc[N + 1], dma_desc[N + 2] yet. Now things will go\nhorribly wrong, DMA is going to access a unmapped/unreferenced memory\nregion, corrupted data will be transmited or iommu fault will be\ntriggered :(\n\nIn contrast, the for-loop that maps SKB fragments behaves perfectly\nas expected, and that is how the driver should do for both non-paged\ndata and paged frags actually.\n\nThis patch corrects DMA map/unmap sequences by fixing the array index\nfor tx_q-\u003etx_skbuff_dma[entry].buf when assigning DMA buffer address.\n\nTested and verified on DWXGMAC CORE 3.20a",
"id": "GHSA-wp26-g22c-7r5j",
"modified": "2024-11-22T21:32:13Z",
"published": "2024-11-19T18:31:07Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-53058"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/07c9c26e37542486e34d767505e842f48f29c3f6"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/58d23d835eb498336716cca55b5714191a309286"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/66600fac7a984dea4ae095411f644770b2561ede"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a3ff23f7c3f0e13f718900803e090fd3997d6bc9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ece593fc9c00741b682869d3f3dc584d37b7c9df"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
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