REF: https://bugzilla.tianocore.org/show_bug.cgi?id=704
For root directory, the FID (File Identifier Descriptor) pointer is accessible through PRIVATE_UDF_FILE_DATA.Root, whereas non-root directory and regular files, their FIDs are accessible through PRIVATE_UDF_FILE_DATA.File. In UdfSetPosition(), the FID was retrieved through PRIVATE_UDF_FILE_DATA.File, hence when calling it with a root directory, PRIVATE_UDF_FILE_DATA.File.FileIdentifierDescriptor would be NULL and then dereferenced. This patch fixes the NULL pointer dereference by calling _FILE() to transparently return the correct UDF_FILE_INFO * which points to a valid FID descriptor of a specific file. Cc: Star Zeng <star.z...@intel.com> Cc: Eric Dong <eric.d...@intel.com> Cc: Ruiyu Ni <ruiyu...@intel.com> Cc: Laszlo Ersek <ler...@redhat.com> Cc: Steven Shi <steven....@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Reported-by: Steven Shi <steven....@intel.com> Signed-off-by: Paulo Alcantara <pca...@zytor.com> --- MdeModulePkg/Universal/Disk/UdfDxe/File.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/MdeModulePkg/Universal/Disk/UdfDxe/File.c b/MdeModulePkg/Universal/Disk/UdfDxe/File.c index 8b9339567f..a1eb2196df 100644 --- a/MdeModulePkg/Universal/Disk/UdfDxe/File.c +++ b/MdeModulePkg/Universal/Disk/UdfDxe/File.c @@ -690,7 +690,8 @@ UdfSetPosition ( PrivFileData = PRIVATE_UDF_FILE_DATA_FROM_THIS (This); - FileIdentifierDesc = PrivFileData->File.FileIdentifierDesc; + FileIdentifierDesc = _FILE (PrivFileData)->FileIdentifierDesc; + ASSERT (FileIdentifierDesc != NULL); if (IS_FID_DIRECTORY_FILE (FileIdentifierDesc)) { // // If the file handle is a directory, the _only_ position that may be set is -- 2.11.0 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel