CVE-2022-48809

Summary

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

net: fix a memleak when uncloning an skb dst and its metadata

When uncloning an skb dst and its associated metadata, a new dst+metadata is allocated and later replaces the old one in the skb. This is helpful to have a non-shared dst+metadata attached to a specific skb.

The issue is the uncloned dst+metadata is initialized with a refcount of 1, which is increased to 2 before attaching it to the skb. When tun_dst_unclone returns, the dst+metadata is only referenced from a single place (the skb) while its refcount is 2. Its refcount will never drop to 0 (when the skb is consumed), leading to a memory leak.

Fix this by removing the call to dst_hold in tun_dst_unclone, as the dst+metadata refcount is already 1.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxfc4099f17240767554ff3a73977acb78ef615404 < 4ac84498fbe84a00e7aef185e2bb3e40ce71eca4affected
LinuxLinuxfc4099f17240767554ff3a73977acb78ef615404 < c1ff27d100e2670b03cbfddb9117e5f9fc672540affected
LinuxLinuxfc4099f17240767554ff3a73977acb78ef615404 < 0be943916d781df2b652793bb2d3ae4f9624c10aaffected
LinuxLinuxfc4099f17240767554ff3a73977acb78ef615404 < a80817adc2a4c1ba26a7aa5f3ed886e4a18dff88affected
LinuxLinuxfc4099f17240767554ff3a73977acb78ef615404 < 00e6d6c3bc14dfe32824e2c515f0e0f2d6ecf2f1affected
LinuxLinuxfc4099f17240767554ff3a73977acb78ef615404 < fdcb263fa5cda15b8cb24a641fa2718c47605314affected
LinuxLinuxfc4099f17240767554ff3a73977acb78ef615404 < 8b1087b998e273f07be13dcb5f3ca4c309c7f108affected
LinuxLinuxfc4099f17240767554ff3a73977acb78ef615404 < 9eeabdf17fa0ab75381045c867c370f4cc75a613affected
LinuxLinux4.3affected
LinuxLinux0 < 4.3unaffected
LinuxLinux4.9.302 <= 4.9.*unaffected
LinuxLinux4.14.267 <= 4.14.*unaffected
LinuxLinux4.19.230 <= 4.19.*unaffected
LinuxLinux5.4.180 <= 5.4.*unaffected
LinuxLinux5.10.101 <= 5.10.*unaffected
LinuxLinux5.15.24 <= 5.15.*unaffected
LinuxLinux5.16.10 <= 5.16.*unaffected
LinuxLinux5.17 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References