CVE-2022-49345

Summary

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

net: xfrm: unexport __init-annotated xfrm4_protocol_init()

EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic.

modpost used to detect it, but it has been broken for a decade.

Recently, I fixed modpost so it started to warn it again, then this showed up in linux-next builds.

There are two ways to fix it:

  • Remove __init
  • Remove EXPORT_SYMBOL

I chose the latter for this case because the only in-tree call-site, net/ipv4/xfrm4_policy.c is never compiled as modular. (CONFIG_XFRM is boolean)

Affected Software

VendorProductVersion RangeStatus
LinuxLinux2f32b51b609faea1e40bb8c5bd305f1351740936 < c58d82a1264813e69119c13e9804e2e60b664ad5affected
LinuxLinux2f32b51b609faea1e40bb8c5bd305f1351740936 < e53cd3814504b2cadaba4d5a8a07eeea9ddacd03affected
LinuxLinux2f32b51b609faea1e40bb8c5bd305f1351740936 < 31f3c6a4dcd3260a386e62cef2d5b36e902600a1affected
LinuxLinux2f32b51b609faea1e40bb8c5bd305f1351740936 < ef6d2354de238b065d8799c80da4be9a6af18e39affected
LinuxLinux2f32b51b609faea1e40bb8c5bd305f1351740936 < be3884d5cd04ccd58294b83a02d70b7c5fca19d3affected
LinuxLinux2f32b51b609faea1e40bb8c5bd305f1351740936 < 85a055c03691e51499123194a14a0c249cf33227affected
LinuxLinux2f32b51b609faea1e40bb8c5bd305f1351740936 < e04d59cfe0c0129df7aba7ef7bb17b96be2a64f2affected
LinuxLinux2f32b51b609faea1e40bb8c5bd305f1351740936 < 2b253fbc9f7b5db18d716436bdcf8ecef09fd63daffected
LinuxLinux2f32b51b609faea1e40bb8c5bd305f1351740936 < 4a388f08d8784af48f352193d2b72aaf167a57a1affected
LinuxLinux3.15affected
LinuxLinux0 < 3.15unaffected
LinuxLinux4.9.318 <= 4.9.*unaffected
LinuxLinux4.14.283 <= 4.14.*unaffected
LinuxLinux4.19.247 <= 4.19.*unaffected
LinuxLinux5.4.198 <= 5.4.*unaffected
LinuxLinux5.10.122 <= 5.10.*unaffected
LinuxLinux5.15.47 <= 5.15.*unaffected
LinuxLinux5.17.15 <= 5.17.*unaffected
LinuxLinux5.18.4 <= 5.18.*unaffected
LinuxLinux5.19 <= *unaffected

Weaknesses

References