CVE-2026-80550
Description
AI Translation Available
In the Linux kernel, the following vulnerability has been resolved:
s390/vfio_ccw: Fix out of bounds check on CCW array
The routine ccwchain_calc_length() counts the number of channel
command words (CCWs) that are chained together in a single channel
program, and rejects anything larger than CCWCHAIN_LEN_MAX (256) CCWs.
The loop itself is 'do..while (count < 257)', and while the logic in
is_cpa_within_range() correctly adjusts between the 0-index array of
CCWs and the count of CCWs starting at 1, this means it would look
at a possible 257th CCW before ending the loop and (correctly)
returning an error.
Fix this by restructuring the loop to break as soon as 256 CCWs
(thus indexes 0-255) are examined, without looking at memory
outside the range.
https://git.kernel.org/stable/c/0282fb1c4b638eecfe2cc558092c460911d8f7e2
https://git.kernel.org/stable/c/499a8a66b1598bfab97182aed15e0f1646074a3d
https://git.kernel.org/stable/c/4c2e1d359d7a2b82cdf3254e4e480af9417f99fb
https://git.kernel.org/stable/c/907adc667d902fafbdb2d740d57b55bd025dc4cd
https://git.kernel.org/stable/c/a005b7f1a491ffda61bff0fd0f6548f8986fb977
https://git.kernel.org/stable/c/af3f80ca4c8b17f20f9e588def076288fdb49e65
https://git.kernel.org/stable/c/d5d096cd9369e986d4e5153baa86b8b35c283e09
https://git.kernel.org/stable/c/f20be33d093ce7630c17ff7ed93caf7eaf8ac1a3