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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-81009

io_uring/query: cap user size passed to copy_struct_to_user

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/query: cap user size passed to copy_struct_to_user io_handle_query_entry() clamps hdr.size for the inbound copy_from_user() but keeps the original user value as usize. copy_struct_to_user() uses that usize and, when it is larger than the kernel result, clear_user()s the trailing bytes. As hdr.size is a __u32, a query can request nearly 4 GiB of zeroing, including on the error path where res_size stays 0. The interface is reachable without a ring via IORING_REGISTER_QUERY. Reject sizes larger than PAGE_SIZE, as recommended for copy_struct_* interfaces.

Affected products

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

Linux Linux

Default version status: unaffected

  • c265ae75f900cea4e415230a77b5d152377627dd to < 417e02f7b6051765b91cf1289071882eebd172e0affected
  • c265ae75f900cea4e415230a77b5d152377627dd to < 2b8ad4981ecedb14c1fdd811ab977010b23933e6affected
  • c265ae75f900cea4e415230a77b5d152377627dd to < ba77efee1b95b4ad7559b1cdbe7cd7fa36dca95baffected

Linux Linux

Default version status: affected

  • 6.18affected
  • 0 to < 6.18unaffected
  • 6.18.50 to ≤ 6.18.*unaffected
  • 7.2.4 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References