CVE-2026-89503

Summary

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

ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()

ring_buffer_alloc_read_page() is racy with ring_buffer_subbuf_order_set, it can allocate a reader page with an outdated order. This isn't a big issue, the user can still re-allocate a new reader page and try again.

However, what is more problematic is if the value of subbuf_order changes in the middle of ring_buffer_alloc_read_page(). In that case, bpage->order might not match the actual allocated memory.

Use bpage->order for the allocation to prevent this race.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxbce761d757452ba5eb77e11fecc37a04b67494e7 < 2dc510957fe8fd098ab3c3147ebdf34d00cd2734affected
LinuxLinuxbce761d757452ba5eb77e11fecc37a04b67494e7 < 53106e9262a310ef2c9a9321168c03705940c678affected
LinuxLinuxbce761d757452ba5eb77e11fecc37a04b67494e7 < e743527c5bfdceda1095bc0a9e596e2aebb6a9c3affected
LinuxLinux6.8affected
LinuxLinux0 < 6.8unaffected
LinuxLinux6.18.50 <= 6.18.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References