CVE-2021-46952

Summary

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

NFS: fs_context: validate UDP retrans to prevent shift out-of-bounds

Fix shift out-of-bounds in xprt_calc_majortimeo(). This is caused by a garbage timeout (retrans) mount option being passed to nfs mount, in this case from syzkaller.

If the protocol is XPRT_TRANSPORT_UDP, then 'retrans' is a shift value for a 64-bit long integer, so 'retrans' cannot be >= 64. If it is >= 64, fail the mount and return an error.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux9954bf92c0cddd50a2a470be302e1c1ffdf21d42 < 96fa26b74cdcf9f5c98996bf36bec9fb5b19ffe2affected
LinuxLinux9954bf92c0cddd50a2a470be302e1c1ffdf21d42 < 2f3380121d49e829fb73ba86240c181bc32ad897affected
LinuxLinux9954bf92c0cddd50a2a470be302e1c1ffdf21d42 < 3d0163821c035040a46d816a42c0780f0f0a30a8affected
LinuxLinux9954bf92c0cddd50a2a470be302e1c1ffdf21d42 < c09f11ef35955785f92369e25819bf0629df2e59affected
LinuxLinux5.6affected
LinuxLinux0 < 5.6unaffected
LinuxLinux5.10.36 <= 5.10.*unaffected
LinuxLinux5.11.20 <= 5.11.*unaffected
LinuxLinux5.12.3 <= 5.12.*unaffected
LinuxLinux5.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

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

CVE Program Container

Additional References

References