diff --git a/changelog/unreleased/issue-5003 b/changelog/unreleased/issue-5003 new file mode 100644 index 000000000..d02b06bc7 --- /dev/null +++ b/changelog/unreleased/issue-5003 @@ -0,0 +1,14 @@ +Bugfix: fix metadata errors during backup of removable disks on Windows + +Since restic 0.17.0, backups of removable disks on Windows could report +errors with retrieving metadata like shown below. + +``` +error: incomplete metadata for d:\filename: get named security info failed with: Access is denied. +``` + +This has now been fixed. + +https://github.com/restic/restic/issues/5003 +https://github.com/restic/restic/pull/5123 +https://forum.restic.net/t/backing-up-a-folder-from-a-veracrypt-volume-brings-up-errors-since-restic-v17-0/8444 diff --git a/internal/fs/sd_windows.go b/internal/fs/sd_windows.go index 0004f1809..a39c06f2c 100644 --- a/internal/fs/sd_windows.go +++ b/internal/fs/sd_windows.go @@ -54,6 +54,15 @@ func GetSecurityDescriptor(filePath string) (securityDescriptor *[]byte, err err sd, err = getNamedSecurityInfoLow(filePath) } else { sd, err = getNamedSecurityInfoHigh(filePath) + // Fallback to the low privilege version when receiving an access denied error. + // For some reason the ERROR_PRIVILEGE_NOT_HELD error is not returned for removable media + // but instead an access denied error is returned. Workaround that by just retrying with + // the low privilege version, but don't switch privileges as we cannot distinguish this + // case from actual access denied errors. + // see https://github.com/restic/restic/issues/5003#issuecomment-2452314191 for details + if err != nil && isAccessDeniedError(err) { + sd, err = getNamedSecurityInfoLow(filePath) + } } if err != nil { if !useLowerPrivileges && isHandlePrivilegeNotHeldError(err) { @@ -114,6 +123,10 @@ func SetSecurityDescriptor(filePath string, securityDescriptor *[]byte) error { err = setNamedSecurityInfoLow(filePath, dacl) } else { err = setNamedSecurityInfoHigh(filePath, owner, group, dacl, sacl) + // See corresponding fallback in getSecurityDescriptor for an explanation + if err != nil && isAccessDeniedError(err) { + err = setNamedSecurityInfoLow(filePath, dacl) + } } if err != nil { @@ -174,6 +187,15 @@ func isHandlePrivilegeNotHeldError(err error) bool { return false } +// isAccessDeniedError checks if the error is ERROR_ACCESS_DENIED +func isAccessDeniedError(err error) bool { + if errno, ok := err.(syscall.Errno); ok { + // Compare the error code to the expected value + return errno == windows.ERROR_ACCESS_DENIED + } + return false +} + // SecurityDescriptorBytesToStruct converts the security descriptor bytes representation // into a pointer to windows SECURITY_DESCRIPTOR. func SecurityDescriptorBytesToStruct(sd []byte) (*windows.SECURITY_DESCRIPTOR, error) {