CVE-2024-36930 spi: fix null pointer dereference within spi_sync

2024-05-3015:29:22

Linux

www.cve.org

linux kernel

vulnerability

spi

null pointer dereference

callback

function inlining

call stack

transfer message

spi_sync

cve

6.5 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

5.1%

JSON

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

spi: fix null pointer dereference within spi_sync

If spi_sync() is called with the non-empty queue and the same spi_message
is then reused, the complete callback for the message remains set while
the context is cleared, leading to a null pointer dereference when the
callback is invoked from spi_finalize_current_message().

With function inlining disabled, the call stack might look like this:

_raw_spin_lock_irqsave from complete_with_flags+0x18/0x58
complete_with_flags from spi_complete+0x8/0xc
spi_complete from spi_finalize_current_message+0xec/0x184
spi_finalize_current_message from spi_transfer_one_message+0x2a8/0x474
spi_transfer_one_message from __spi_pump_transfer_message+0x104/0x230
__spi_pump_transfer_message from __spi_transfer_message_noqueue+0x30/0xc4
__spi_transfer_message_noqueue from __spi_sync+0x204/0x248
__spi_sync from spi_sync+0x24/0x3c
spi_sync from mcp251xfd_regmap_crc_read+0x124/0x28c [mcp251xfd]
mcp251xfd_regmap_crc_read [mcp251xfd] from _regmap_raw_read+0xf8/0x154
_regmap_raw_read from _regmap_bus_read+0x44/0x70
_regmap_bus_read from _regmap_read+0x60/0xd8
_regmap_read from regmap_read+0x3c/0x5c
regmap_read from mcp251xfd_alloc_can_err_skb+0x1c/0x54 [mcp251xfd]
mcp251xfd_alloc_can_err_skb [mcp251xfd] from mcp251xfd_irq+0x194/0xe70 [mcp251xfd]
mcp251xfd_irq [mcp251xfd] from irq_thread_fn+0x1c/0x78
irq_thread_fn from irq_thread+0x118/0x1f4
irq_thread from kthread+0xd8/0xf4
kthread from ret_from_fork+0x14/0x28

Fix this by also setting message->complete to NULL when the transfer is
complete.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/spi/spi.c"
    ],
    "versions": [
      {
        "version": "ae7d2346dc89",
        "lessThan": "e005d6754e3e",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "ae7d2346dc89",
        "lessThan": "a30659f1576d",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "ae7d2346dc89",
        "lessThan": "2070d008cc08",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "ae7d2346dc89",
        "lessThan": "4756fa529b2f",
        "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/spi/spi.c"
    ],
    "versions": [
      {
        "version": "6.0",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "6.0",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.91",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.31",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8.10",
        "lessThanOrEqual": "6.8.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]