CVE-2024-41088 can: mcp251xfd: fix infinite loop when xmit fails

2024-07-2915:48:04

Linux

www.cve.org

linux kernel

mcp251xfd

infinite loop

EPSS

Percentile

5.0%

JSON

In the Linux kernel, the following vulnerability has been resolved:

can: mcp251xfd: fix infinite loop when xmit fails

When the mcp251xfd_start_xmit() function fails, the driver stops
processing messages, and the interrupt routine does not return,
running indefinitely even after killing the running application.

Error messages:
[ 441.298819] mcp251xfd spi2.0 can0: ERROR in mcp251xfd_start_xmit: -16
[ 441.306498] mcp251xfd spi2.0 can0: Transmit Event FIFO buffer not empty. (seq=0x000017c7, tef_tail=0x000017cf, tef_head=0x000017d0, tx_head=0x000017d3).
… and repeat forever.

The issue can be triggered when multiple devices share the same SPI
interface. And there is concurrent access to the bus.

The problem occurs because tx_ring->head increments even if
mcp251xfd_start_xmit() fails. Consequently, the driver skips one TX
package while still expecting a response in
mcp251xfd_handle_tefif_one().

Resolve the issue by starting a workqueue to write the tx obj
synchronously if err = -EBUSY. In case of another error, decrement
tx_ring->head, remove skb from the echo stack, and drop the message.

[mkl: use more imperative wording in patch description]

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c",
      "drivers/net/can/spi/mcp251xfd/mcp251xfd-tx.c",
      "drivers/net/can/spi/mcp251xfd/mcp251xfd.h"
    ],
    "versions": [
      {
        "version": "55e5b97f003e",
        "lessThan": "f926c022ebaa",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "55e5b97f003e",
        "lessThan": "3e72558c1711",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "55e5b97f003e",
        "lessThan": "6c6b4afa59c2",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "55e5b97f003e",
        "lessThan": "d8fb63e46c88",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c",
      "drivers/net/can/spi/mcp251xfd/mcp251xfd-tx.c",
      "drivers/net/can/spi/mcp251xfd/mcp251xfd.h"
    ],
    "versions": [
      {
        "version": "5.10",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.10",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.97",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.37",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9.8",
        "lessThanOrEqual": "6.9.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]