CVE-2024-42317 — mm/huge_memory: avoid PMD-size page cache if needed

Affected: Linux

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

mm/huge_memory: avoid PMD-size page cache if needed

xarray can't support arbitrary page cache size. the largest and supported page cache size is defined as MAX_PAGECACHE_ORDER by commit 099d90642a71 ("mm/filemap: make MAX_PAGECACHE_ORDER acceptable to xarray"). However, it's possible to have 512MB page cache in the huge memory's collapsing path on ARM64 system whose base page size is 64KB. 512MB page cache is breaking the limitation and a warning is raised when the xarray entry is split as shown in the following example.

[root@dhcp-10-26-1-207 ~]# cat /proc/1/smaps | grep KernelPageSize KernelPageSize: 64 kB [root@dhcp-10-26-1-207 ~]# cat /tmp/test.c : int main(int argc, char **argv) { const char *filename = TEST_XFS_FILENAME; int fd = 0; void *buf = (void *)-1, *p; int pgsize = getpagesize(); int ret = 0;

if (pgsize != 0x10000) { fprintf(stdout, "System with 64KB base page size is required!\n"); return -EPERM; }

system("echo 0 > /sys/devices/virtual/bdi/253:0/read_ahead_kb"); system("echo 1 > /proc/sys/vm/drop_caches");

/* Open the xfs file */ fd = open(filename, O_RDONLY); assert(fd > 0);

/* Create VMA */ buf = mmap(NULL, TEST_MEM_SIZE, PROT_READ, MAP_SHARED, fd, 0); assert(buf != (void *)-1); fprintf(stdout, "mapped buffer at 0x%p\n", buf);

/* Populate VMA */ ret = madvise(buf, TEST_MEM_SIZE, MADV_NOHUGEPAGE); assert(ret == 0); ret = madvise(buf, TEST_MEM_SIZE,…

USN-7154-1 — linux, linux-aws, linux-aws-6.8, linux-gcp, linux-gcp-6.8, linux-gke, linux-ibm, linux-lowlatency, linux-lowlatency-hwe…

Affected: Ubuntu:22.04:LTS: linux-aws-6.8, Ubuntu:22.04:LTS: linux-gcp-6.8, Ubuntu:22.04:LTS: linux-lowlatency-hwe-6.8, Ubuntu:22.04:LTS: linux-oracle-6.8, Ubuntu:24.04:LTS: linux, Ubuntu:24.04:LTS: linux-aws, Ubuntu:24.04:LTS: linux-gcp, Ubuntu:24.04:LTS: linux-gke, Ubuntu:24.04:LTS: linux-ibm, Ubuntu:24.04:LTS: linux-lowlatency and 3 more

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; - MIPS architecture; - PowerPC architecture; - RISC-V architecture; - S390 architecture; - User-Mode Linux (UML); - x86 architecture; - Block layer subsystem; - Android drivers; - ATM drivers; - Drivers core; - Ublk userspace block driver; - Bluetooth drivers; - Character device driver; - Hardware crypto device drivers; - Buffer Sharing and Synchronization framework; - DMA engine subsystem; - Qualcomm firmware drivers; - GPIO subsystem; - GPU drivers; - HID subsystem; - Hardware monitoring drivers; - I2C subsystem; - I3C subsystem; - IIO subsystem; - InfiniBand drivers; - Input Device core drivers; - Input Device (Miscellaneous) drivers; - IOMMU subsystem; - IRQ chip drivers; - LED subsystem; - Mailbox framework; - Multiple devices driver; - Media drivers; - Fastrpc Driver; - VMware VMCI Driver; - MMC subsystem; - Ethernet bonding driver; - Network drivers; - Mellanox network drivers; - Microsoft Azure Network Adapter (MANA) driver; - Near Field Communication (NFC) drivers; - NVME drivers; - Device tree and open firmware driver; - Parport drivers; - PCI subsystem; - Pin controllers subsystem; - x86 platform drivers; - Power supply drivers; - Remote Processor subsystem; - S/390…

Most recent entries from all

CVE-2024-42317 — mm/huge_memory: avoid PMD-size page cache if needed

USN-7154-1 — linux, linux-aws, linux-aws-6.8, linux-gcp, linux-gcp-6.8, linux-gke, linux-ibm, linux-lowlatency, linux-lowlatency-hwe…