CVE-2024-50182 — secretmem: disable memfd_secret() if arch cannot set direct map

Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

secretmem: disable memfd_secret() if arch cannot set direct map

Return -ENOSYS from memfd_secret() syscall if !can_set_direct_map(). This is the case for example on some arm64 configurations, where marking 4k PTEs in the direct map not present can only be done if the direct map is set up at 4k granularity in the first place (as ARM's break-before-make semantics do not easily allow breaking apart large/gigantic pages).

More precisely, on arm64 systems with !can_set_direct_map(), set_direct_map_invalid_noflush() is a no-op, however it returns success (0) instead of an error. This means that memfd_secret will seemingly "work" (e.g. syscall succeeds, you can mmap the fd and fault in pages), but it does not actually achieve its goal of removing its memory from the direct map.

Note that with this patch, memfd_secret() will start erroring on systems where can_set_direct_map() returns false (arm64 with CONFIG_RODATA_FULL_DEFAULT_ENABLED=n, CONFIG_DEBUG_PAGEALLOC=n and CONFIG_KFENCE=n), but that still seems better than the current silent failure. Since CONFIG_RODATA_FULL_DEFAULT_ENABLED defaults to 'y', most arm64 systems actually have a working memfd_secret() and aren't be affected.

From going through the iterations of the original memfd_secret patch series, it seems that disabling the syscall in these scenarios was the intended behavior [1] (preferred over having set_direct_map_invalid_noflush return an er…

USN-7276-1 — linux, linux-lowlatency vulnerabilities

Affected: Ubuntu:24.10: linux, Ubuntu:24.10: linux-lowlatency

Attila Szász discovered that the HFS+ file system implementation in the Linux Kernel contained a heap overflow vulnerability. An attacker could use a specially crafted file system image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2025-0927)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - ARM32 architecture; - ARM64 architecture; - PowerPC architecture; - RISC-V architecture; - S390 architecture; - SuperH RISC architecture; - User-Mode Linux (UML); - x86 architecture; - Block layer subsystem; - Cryptographic API; - Compute Acceleration Framework; - ACPI drivers; - Drivers core; - ATA over ethernet (AOE) driver; - RAM backed block device driver; - Network block device driver; - Ublk userspace block driver; - Compressed RAM block device driver; - Bluetooth drivers; - TPM device driver; - Clock framework and drivers; - Data acquisition framework and drivers; - CPU frequency scaling framework; - Hardware crypto device drivers; - CXL (Compute Express Link) drivers; - DAX dirext access to differentiated memory framework; - Buffer Sharing and Synchronization framework; - EDAC drivers; - FireWire subsystem; - ARM SCMI message protocol; - ARM SCPI message protocol; - EFI core; - Qualcomm firmware drivers; - GPIO subsystem;…

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CVE-2024-50182 — secretmem: disable memfd_secret() if arch cannot set direct map

USN-7276-1 — linux, linux-lowlatency vulnerabilities