In the Linux kernel, the following vulnerability has been resolved:
cxl/region: Fix region HPA ordering validation
Some regions may not have any address space allocated. Skip them when validating HPA order otherwise a crash like the following may result:
devmcxladdregion: cxlacpi cxlacpi.0: decoder3.4: created region9 BUG: kernel NULL pointer dereference, address: 0000000000000000 [..] RIP: 0010:storetargetN+0x655/0x1740 [cxlcore] [..] Call Trace: <TASK> kernfsfopwriteiter+0x144/0x200 vfswrite+0x24a/0x4d0 ksyswrite+0x69/0xf0 dosyscall64+0x3a/0x90
storetargetN+0x655/0x1740: allocregionref at drivers/cxl/core/region.c:676 (inlined by) cxlportattachregion at drivers/cxl/core/region.c:850 (inlined by) cxlregionattach at drivers/cxl/core/region.c:1290 (inlined by) attachtarget at drivers/cxl/core/region.c:1410 (inlined by) storetargetN at drivers/cxl/core/region.c:1453