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CVE PROGRAM SOURCE RECORD7.8 High

CVE-2021-3491

Linux kernel io_uring PROVIDE_BUFFERS MAX_RW_COUNT bypass

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Status
Published
Published
Updated
Assigning organization
canonical

Description

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 products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux kernel

  • trunk to < v5.13-rc4affected
  • linux-5.12.y to < v5.12.4affected
  • linux-5.11.y to < v5.11.21affected
  • linux-5.10.y to < v5.10.37affected
  • v5.7-rc1 to < 5.7*affected

References