diff options
| author | Naman Jain <namjain@linux.microsoft.com> | 2026-04-06 09:24:59 +0000 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2026-04-14 04:44:31 +0000 |
| commit | 404cd6bffe17e25e0f94ed2775ffdd6cd10ac3fd (patch) | |
| tree | 11f5a31ff97c3da499e22f3afd07924846eac0fb /include | |
| parent | ca5ee0e918115fb5cf626d75461d9fca06e06caf (diff) | |
mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER
When registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel
computes pgmap->vmemmap_shift as the number of trailing zeros in the
OR of start_pfn and last_pfn, intending to use the largest compound
page order both endpoints are aligned to.
However, this value is not clamped to MAX_FOLIO_ORDER, so a
sufficiently aligned range (e.g. physical range
[0x800000000000, 0x800080000000), corresponding to start_pfn=0x800000000
with 35 trailing zeros) can produce a shift larger than what
memremap_pages() accepts, triggering a WARN and returning -EINVAL:
WARNING: ... memremap_pages+0x512/0x650
requested folio size unsupported
The MAX_FOLIO_ORDER check was added by
commit 646b67d57589 ("mm/memremap: reject unreasonable folio/compound
page sizes in memremap_pages()").
Fix this by clamping vmemmap_shift to MAX_FOLIO_ORDER so we always
request the largest order the kernel supports, in those cases, rather
than an out-of-range value.
Also fix the error path to propagate the actual error code from
devm_memremap_pages() instead of hard-coding -EFAULT, which was
masking the real -EINVAL return.
Fixes: 7bfe3b8ea6e3 ("Drivers: hv: Introduce mshv_vtl driver")
Cc: stable@vger.kernel.org
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/mshv.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h index e0645a34b55b..32ff92b6342b 100644 --- a/include/uapi/linux/mshv.h +++ b/include/uapi/linux/mshv.h @@ -357,7 +357,7 @@ struct mshv_vtl_sint_post_msg { struct mshv_vtl_ram_disposition { __u64 start_pfn; - __u64 last_pfn; + __u64 last_pfn; /* last_pfn is excluded from the range [start_pfn, last_pfn) */ }; struct mshv_vtl_set_poll_file { |