[edk2-devel] [PATCH] OvmfPkg/VirtioFsDxe: call IsTimeValid() before EfiTimeToEpoch()
Laszlo Ersek
lersek at redhat.com
Thu Jan 7 09:50:51 UTC 2021
EmbeddedPkg/TimeBaseLib provides a verification function called
IsTimeValid(), for enforcing the UEFI spec requirements on an EFI_TIME
object.
When EFI_FILE_PROTOCOL.SetInfo() is called in order to update the
timestamps on the file, let's invoke IsTimeValid() first, before passing
the new EFI_FILE_INFO.{CreateTime,LastAccessTime,ModificationTime} values
to EfiTimeToEpoch().
This patch is not expected to make a practical difference, but it's better
to ascertain the preconditions of EfiTimeToEpoch() on the
EFI_FILE_PROTOCOL.SetInfo() caller. The FAT driver (EnhancedFatDxe) has a
similar check, namely in FatSetFileInfo() -> FatIsValidTime().
Cc: Ard Biesheuvel <ard.biesheuvel at arm.com>
Cc: Jordan Justen <jordan.l.justen at intel.com>
Cc: Philippe Mathieu-Daudé <philmd at redhat.com>
Signed-off-by: Laszlo Ersek <lersek at redhat.com>
---
OvmfPkg/VirtioFsDxe/Helpers.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/OvmfPkg/VirtioFsDxe/Helpers.c b/OvmfPkg/VirtioFsDxe/Helpers.c
index 443bbdc616ac..b81c04e0a4e8 100644
--- a/OvmfPkg/VirtioFsDxe/Helpers.c
+++ b/OvmfPkg/VirtioFsDxe/Helpers.c
@@ -2237,26 +2237,33 @@ VirtioFsGetFuseSizeUpdate (
@param[out] Atime If UpdateAtime is set to TRUE, then Atime provides
the last access timestamp to set (as seconds since
the Epoch). Otherwise, Atime is not written to.
@param[out] Mtime If UpdateMtime is set to TRUE, then Mtime provides
the last modification timestamp to set (as seconds
since the Epoch). Otherwise, Mtime is not written
to.
- @retval EFI_SUCCESS Output parameters have been set successfully.
+ @retval EFI_SUCCESS Output parameters have been set successfully.
- @retval EFI_ACCESS_DENIED NewInfo requests changing both CreateTime and
- ModificationTime, but to values that differ from
- each other. The Virtio Filesystem device does not
- support this.
+ @retval EFI_INVALID_PARAMETER At least one of the CreateTime, LastAccessTime
+ and ModificationTime fields in NewInfo
+ represents an actual update relative to the
+ current state of the file (expressed in Info),
+ but does not satisfy the UEFI spec
+ requirements on EFI_TIME.
+
+ @retval EFI_ACCESS_DENIED NewInfo requests changing both CreateTime and
+ ModificationTime, but to values that differ
+ from each other. The Virtio Filesystem device
+ does not support this.
**/
EFI_STATUS
VirtioFsGetFuseTimeUpdates (
IN EFI_FILE_INFO *Info,
IN EFI_FILE_INFO *NewInfo,
OUT BOOLEAN *UpdateAtime,
OUT BOOLEAN *UpdateMtime,
OUT UINT64 *Atime,
OUT UINT64 *Mtime
)
@@ -2278,20 +2285,23 @@ VirtioFsGetFuseTimeUpdates (
//
// Determine which timestamps differ from the current state. (A zero time
// means "don't update", per UEFI spec.) For each timestamp that's being
// changed, calculate the seconds since the Epoch.
//
for (Idx = 0; Idx < ARRAY_SIZE (Time); Idx++) {
if (CompareMem (NewTime[Idx], &ZeroTime, sizeof (EFI_TIME)) == 0 ||
CompareMem (NewTime[Idx], Time[Idx], sizeof (EFI_TIME)) == 0) {
Change[Idx] = FALSE;
} else {
+ if (!IsTimeValid (NewTime[Idx])) {
+ return EFI_INVALID_PARAMETER;
+ }
Change[Idx] = TRUE;
Seconds[Idx] = EfiTimeToEpoch (NewTime[Idx]);
}
}
//
// If a change is requested for exactly one of CreateTime and
// ModificationTime, we'll change the last modification time. If changes are
// requested for both, and to the same timestamp, we'll similarly update the
// last modification time. If changes are requested for both, but to
--
2.19.1.3.g30247aa5d201
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