CVE-2022-48908

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

net: arcnet: com20020: Fix null-ptr-deref in com20020pci_probe()

During driver initialization, the pointer of card info, i.e. the variable ci is required. However, the definition of com20020pci_id_table reveals that this field is empty for some devices, which will cause null pointer dereference when initializing these devices.

The following log reveals it:

[ 3.973806] KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] [ 3.973819] RIP: 0010:com20020pci_probe+0x18d/0x13e0 [com20020_pci] [ 3.975181] Call Trace: [ 3.976208] local_pci_probe+0x13f/0x210 [ 3.977248] pci_device_probe+0x34c/0x6d0 [ 3.977255] ? pci_uevent+0x470/0x470 [ 3.978265] really_probe+0x24c/0x8d0 [ 3.978273] __driver_probe_device+0x1b3/0x280 [ 3.979288] driver_probe_device+0x50/0x370

Fix this by checking whether the ci is a null pointer first.

Weakness

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/5f394102ee27dbf051a4e283390cd8d1759dacea
• https://git.kernel.org/stable/c/8e3bc7c5bbf87e86e9cd652ca2a9166942d86206
• https://git.kernel.org/stable/c/b1ee6b9340a38bdb9e5c90f0eac5b22b122c3049
• https://git.kernel.org/stable/c/b838add93e1dd98210482dc433768daaf752bdef
• https://git.kernel.org/stable/c/bd6f1fd5d33dfe5d1b4f2502d3694a7cc13f166d
• https://git.kernel.org/stable/c/ca0bdff4249a644f2ca7a49d410d95b8dacf1f72
• https://git.kernel.org/stable/c/e50c589678e50f8d574612e473ca60ef45190896
• https://git.kernel.org/stable/c/ea372aab54903310756217d81610901a8e66cb7d