CVE-2021-3491

Summary

The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be bypassed in the PROVIDE_BUFFERS operation, which led to negative values being usedin mem_rw when reading /proc/<PID>/mem. This could be used to create a heap overflow leading to arbitrary code execution in the kernel. It was addressed via commit d1f82808877b ("io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers") (v5.13-rc1) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced in ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS") (v5.7-rc1).

Affected Software

VendorProductVersion RangeStatus
LinuxLinux kerneltrunk < v5.13-rc4affected
LinuxLinux kernellinux-5.12.y < v5.12.4affected
LinuxLinux kernellinux-5.11.y < v5.11.21affected
LinuxLinux kernellinux-5.10.y < v5.10.37affected
LinuxLinux kernelv5.7-rc1 < 5.7*affected

Weaknesses

  • CWE-131: CWE-131 Incorrect Calculation of Buffer Size

ADP Enrichment

CVE Program Container

Additional References

References