CVE-2024-45025 — fix bitmap corruption on close_range() with CLOSE_RANGE_UNSHARE

Affected: Linux

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

fix bitmap corruption on close_range() with CLOSE_RANGE_UNSHARE

copy_fd_bitmaps(new, old, count) is expected to copy the first count/BITS_PER_LONG bits from old->full_fds_bits[] and fill the rest with zeroes. What it does is copying enough words (BITS_TO_LONGS(count/BITS_PER_LONG)), then memsets the rest. That works fine, *if* all bits past the cutoff point are clear. Otherwise we are risking garbage from the last word we'd copied.

For most of the callers that is true - expand_fdtable() has count equal to old->max_fds, so there's no open descriptors past count, let alone fully occupied words in ->open_fds[], which is what bits in ->full_fds_bits[] correspond to.

The other caller (dup_fd()) passes sane_fdtable_size(old_fdt, max_fds), which is the smallest multiple of BITS_PER_LONG that covers all opened descriptors below max_fds. In the common case (copying on fork()) max_fds is ~0U, so all opened descriptors will be below it and we are fine, by the same reasons why the call in expand_fdtable() is safe.

Unfortunately, there is a case where max_fds is less than that and where we might, indeed, end up with junk in ->full_fds_bits[] - close_range(from, to, CLOSE_RANGE_UNSHARE) with * descriptor table being currently shared * 'to' being above the current capacity of descriptor table * 'from' being just under some chunk of opened descriptors. In that case we end up with observably wrong behaviour - e.g.…

USN-7088-1 — linux, linux-gcp, linux-gcp-5.4, linux-gkeop, linux-hwe-5.4, linux-ibm, linux-ibm-5.4 vulnerabilities

Affected: Ubuntu:Pro:18.04:LTS: linux-gcp-5.4, Ubuntu:Pro:18.04:LTS: linux-hwe-5.4, Ubuntu:Pro:18.04:LTS: linux-ibm-5.4, Ubuntu:20.04:LTS: linux, Ubuntu:20.04:LTS: linux-gcp, Ubuntu:20.04:LTS: linux-gkeop, Ubuntu:20.04:LTS: linux-ibm

Ziming Zhang discovered that the VMware Virtual GPU DRM driver in the Linux kernel contained an integer overflow vulnerability. A local attacker could use this to cause a denial of service (system crash). (CVE-2022-36402)

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: - ARM64 architecture; - PowerPC architecture; - User-Mode Linux (UML); - x86 architecture; - Block layer subsystem; - Cryptographic API; - Android drivers; - Serial ATA and Parallel ATA drivers; - ATM drivers; - Drivers core; - CPU frequency scaling framework; - Device frequency scaling framework; - GPU drivers; - HID subsystem; - Hardware monitoring drivers; - InfiniBand drivers; - Input Device core drivers; - IOMMU subsystem; - IRQ chip drivers; - ISDN/mISDN subsystem; - LED subsystem; - Multiple devices driver; - Media drivers; - EEPROM drivers; - VMware VMCI Driver; - MMC subsystem; - Network drivers; - Near Field Communication (NFC) drivers; - NVME drivers; - Device tree and open firmware driver; - Parport drivers; - PCI subsystem; - Pin controllers subsystem; - Remote Processor subsystem; - S/390 drivers; - SCSI drivers; - QCOM SoC drivers; - Direct Digital Synthesis drivers; - TTY drivers; - Userspace I/O drivers; - DesignWare USB3 driver; - USB subsystem; - BTRFS file system; - File sy…

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CVE-2024-45025 — fix bitmap corruption on close_range() with CLOSE_RANGE_UNSHARE

USN-7088-1 — linux, linux-gcp, linux-gcp-5.4, linux-gkeop, linux-hwe-5.4, linux-ibm, linux-ibm-5.4 vulnerabilities