Date: Sun, 27 Jun 2021 22:23:10 UTC
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=256422 --- Comment #15 from commit-hook@FreeBSD.org --- A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=91064841d72b285a146a3f1c32cb447251e062ea commit 91064841d72b285a146a3f1c32cb447251e062ea Author: Chuck Tuffli <chuck@FreeBSD.org> AuthorDate: 2021-06-27 22:14:52 +0000 Commit: Chuck Tuffli <chuck@FreeBSD.org> CommitDate: 2021-06-27 22:14:52 +0000 bhyve: Fix NVMe iovec construction for large IOs The UEFI driver included with Rocky Linux 8.4 uncovered an existing bug in the NVMe emulation's construction of iovec's. By default, NVMe data transfer operations use a scatter-gather list in which all entries point to a fixed size memory region. For example, if the Memory Page Size is 4KiB, a 2MiB IO requires 512 entries. Lists themselves are also fixed size (default is 512 entries). Because the list size is fixed, the last entry is special. If the IO requires more than 512 entries, the last entry in the list contains the address of the next list of entries. But if the IO requires exactly 512 entries, the last entry points to data. The NVMe emulation missed this logic and unconditionally treated the last entry as a pointer to the next list. Fix is to check if the remaining data is greater than the page size before using the last entry as a pointer to the next list. PR: 256422 Reported by: firstname.lastname@example.org Tested by: email@example.com MFC after: 5 days Relnotes: yes Reviewed by: imp, grehan Differential Revision: https://reviews.freebsd.org/D30897 usr.sbin/bhyve/pci_nvme.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- You are receiving this mail because: You are the assignee for the bug.