CVE-2024-50271

Summary

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

signal: restore the override_rlimit logic

Prior to commit d64696905554 ("Reimplement RLIMIT_SIGPENDING on top of ucounts") UCOUNT_RLIMIT_SIGPENDING rlimit was not enforced for a class of signals. However now it's enforced unconditionally, even if override_rlimit is set. This behavior change caused production issues.

For example, if the limit is reached and a process receives a SIGSEGV signal, sigqueue_alloc fails to allocate the necessary resources for the signal delivery, preventing the signal from being delivered with siginfo. This prevents the process from correctly identifying the fault address and handling the error. From the user-space perspective, applications are unaware that the limit has been reached and that the siginfo is effectively 'corrupted'. This can lead to unpredictable behavior and crashes, as we observed with java applications.

Fix this by passing override_rlimit into inc_rlimit_get_ucounts() and skip the comparison to max there if override_rlimit is set. This effectively restores the old behavior.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxd64696905554e919321e31afc210606653b8f6a4 < 012f4d5d25e9ef92ee129bd5aa7aa60f692681e1affected
LinuxLinuxd64696905554e919321e31afc210606653b8f6a4 < 4877d9b2a2ebad3ae240127aaa4cb8258b145cf7affected
LinuxLinuxd64696905554e919321e31afc210606653b8f6a4 < 0208ea17a1e4456fbfe555f13ae5c28f3d671e40affected
LinuxLinuxd64696905554e919321e31afc210606653b8f6a4 < 9e05e5c7ee8758141d2db7e8fea2cab34500c6edaffected
LinuxLinux5.14affected
LinuxLinux0 < 5.14unaffected
LinuxLinux6.1.117 <= 6.1.*unaffected
LinuxLinux6.6.61 <= 6.6.*unaffected
LinuxLinux6.11.8 <= 6.11.*unaffected
LinuxLinux6.12 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

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

CVE Program Container

Additional References

References