Tianocore/edk2-platforms.git/Features/Ext4Pkg/Ext4Dxe, branch master

Features/Ext4Pkg: Fix integer overflow in Ext4Read

2026-04-03T22:40:53+00:00

The multiplication of Extent.ee_len (UINT16) and Partition->BlockSize (UINT32) was performed using 32-bit arithmetic, which can overflow before being assigned to the 64-bit ExtentLengthBytes variable. This overflow can lead to an incorrect ExtentMayRead value and subsequent out-of-bounds disk reads. Example: If Partition->BlockSize is 0x200000 (2MB) and Extent.ee_len is 0x800, the result of 0x200000 * 0x800 is 0x100000000. In 32-bit arithmetic, this overflows to 0x0. Consequently, ExtentLengthBytes becomes 0, causing ExtentMayRead to be calculated incorrectly (e.g., underflowing when subtracting ExtentOffset) and potentially leading to an out-of-bounds read in Ext4ReadDiskIo. Casting Extent.ee_len to UINT64 ensures the multiplication is performed using 64-bit arithmetic. Signed-off-by: Phineas Su

Ext4Pkg: remove unused variable in collation code

2025-10-28T17:35:48+00:00

Iso639Language is not used anywhere in the code, so GCC flags it as an unused variable. Signed-off-by: Ariadne Conill

Etxt4Pkg/Ext4Dxe: Deprecate gEfiUnicodeCollationProtocolGuid

2025-09-08T08:33:44+00:00

gEfiUnicodeCollationProtocolGuid was deprecated in favor of a newer version gEfiUnicodeCollation2ProtocolGuid which provides improved language support and better extensibility. It was officially removed from UEFI specifications 2.10A and 2.11 and should no longer be used in current implementations. Cc: Sachin Ganesh Signed-off-by: Gowtham M

Ext4Pkg: Fix CRC16 checksumming on block groups

2023-12-03T23:36:16+00:00

Old filesystems (around 2008 and older) do not use CRC32c but rather CRC16-ANSI. Previously, the CalculateCrc16Ansi function was broken and gave us wrong checksums. Adapt to the new interface. And while we're at it, fix the checksum algorithm itself - the crc16 algorithm just skips over the bg_checksum, and does not checksum it. This problem was found out-of-list when older ext4 filesystems (that use crc16 checksums) failed to mount with "corruption". BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4609 Signed-off-by: Pedro Falcato Cc: Savva Mitrofanov Cc: Marvin Häuser Reviewed-by: Marvin Häuser

Ext4Pkg: Advertise CSUM_SEED as supported

2023-05-09T16:47:54+00:00

We had added support for CSUM_SEED but accidentally forgot to advertise it in gSupportedIncompatFeat. This made it (erroneously) impossible to mount CSUM_SEED filesystems. Detected by attempting to mount a relatively new mkfs.ext4'd filesystem. Cc: Marvin Häuser Signed-off-by: Pedro Falcato Reviewed-by: Marvin Häuser

Ext4Pkg: Improve extent node validation on the number of entries

2023-05-09T16:47:48+00:00

Improve the extent tree node validation by validating the number of entries the node advertises against the theoretical max (derived from the size of on-disk structs and the block size (or i_data, if inline extents). Previously, we did not validate the number of entries. This could be exploited for out-of-bounds reads and crashes. Cc: Marvin Häuser Fixes: d9ceedca6c8f ("Ext4Pkg: Add Ext4Dxe driver.") Reported-by: Savva Mitrofanov Signed-off-by: Pedro Falcato Reviewed-by: Marvin Häuser

Ext4Pkg: Move unicode collation initialization to Start()

2023-02-24T00:29:04+00:00

There have been reports[1] of failures to boot due to unicode collation protocols not being available at Ext4Dxe load time. Therefore, attempt to initialize unicode collation at Start() time, like done previously in FatPkg/EnhancedFatDxe. By doing so, we move collation initialization to BDS, where the module responsible for protocol installation should have already been loaded and ran. [1]: https://edk2.groups.io/g/devel/message/100312 Cc: Ard Biesheuvel Cc: Marvin Häuser Fixes: d9ceedca6c8f ("Ext4Pkg: Add Ext4Dxe driver.") Signed-off-by: Pedro Falcato Acked-by: Ard Biesheuvel Reviewed-by: Marvin Häuser

Ext4Pkg: Fix double-free in Ext4ReadSymlink

2023-02-17T19:03:31+00:00

The SymlinkTmp was deallocated unconditionally, so we shouldn't free it again on EFI_ERROR Cc: Marvin Häuser Cc: Pedro Falcato Cc: Vitaly Cheptsov Fixes: e81432fbacb7 ("Ext4Pkg: Add symbolic links support") Signed-off-by: Savva Mitrofanov Reviewed-by: Marvin Häuser Reviewed-by: Pedro Falcato

Ext4Pkg: Correct memory leak in Ext4ReadSlowSymlink

2023-02-08T16:25:02+00:00

We need to free SymlinkTmp before exiting if SymlinkSizeTmp != ReadSize condition is true. Reported-by: Marvin Häuser Cc: Pedro Falcato Cc: Vitaly Cheptsov Fixes: e81432fbacb7 ("Ext4Pkg: Add symbolic links support") Signed-off-by: Savva Mitrofanov Reviewed-by: Marvin Häuser Reviewed-by: Pedro Falcato

Ext4Pkg: Filter out directory entry names containing \0 as invalid

2023-02-08T16:25:02+00:00

The directory entry name conventions forbid having null-terminator symbols in its body and can lead to undefined behavior conditions and crashes Cc: Marvin Häuser Cc: Pedro Falcato Cc: Vitaly Cheptsov Fixes: 89b2bb0db263 ("Ext4Pkg: Fix and clarify handling regarding non-utf8 dir entries") Signed-off-by: Savva Mitrofanov Reviewed-by: Pedro Falcato Reviewed-by: Marvin Häuser