Hírolvasó

A Gmail-felhasználók számára a Dark Web is monitorozhatóvá válik

2 év 3 hónap óta

A Google bejelentette, hogy minden amerikai Gmail felhasználó számára elérhetővé tenné azt a funkciót, amellyel rákereshetnek az e-mail címükre a dark weben. A Gmail címek dark webes vizsgálata korábban csak az egyesült államokbeli Google One előfizetőknek volt elérhető, viszont a Google az Amerikán túli terjeszkedést is fontolgatja. Miután egy e-mail címet felfedeznek valamely dark webes […]

The post A Gmail-felhasználók számára a Dark Web is monitorozhatóvá válik first appeared on Nemzeti Kibervédelmi Intézet.

NKI

Security updates for Wednesday

2 év 3 hónap óta
Security updates have been issued by Debian (netatalk), Mageia (connman, firefox/nss/rootcerts, freeimage, golang, indent, kernel, python-django, python-pillow, and thunderbird), Red Hat (apr-util, firefox, java-1.8.0-ibm, libreswan, and thunderbird), SUSE (conmon, curl, java-11-openjdk, and libheif), and Ubuntu (libwebp, linux, linux-aws, linux-aws-5.15, linux-azure, linux-azure-5.15, linux-azure-fde, linux-azure-fde-5.15, linux-hwe-5.15, linux-ibm, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-oracle, linux, linux-aws, linux-aws-hwe, linux-kvm, linux, linux-aws, linux-azure, linux-azure-5.19, linux-kvm, linux-lowlatency, linux-raspi, node-eventsource, and openjdk-8, openjdk-lts, openjdk-17, openjdk-20).
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Dave Airlie (blogspot): lavapipe and sparse memory bindings

2 év 3 hónap óta

Mike nerdsniped me into wondering how hard sparse memory support would be in lavapipe.

The answer is unfortunately extremely.

Sparse binding essentially allows creating a vulkan buffer/image of a certain size, then plugging in chunks of memory to back it in page-size multiple chunks.

This works great with GPU APIs where we've designed this, but it's actually hard to pull off on the CPU.

Currently lavapipe allocates memory with an aligned malloc. It allocates objects with no backing and non-sparse bindings connect objects to the malloced memory.

However with sparse objects, the object creation should allocate a chunk of virtual memory space, then sparse binding should bind allocated device memory into the virtual memory space. Except Linux has no interfaces for doing this without using a file descriptor.

You can't mmap a chunk of anonymous memory that you allocated with malloc to another location. So if I malloc backing memory A at 0x1234000, but the virtual memory I've used for the object is at 0x4321000, there's no nice way to get the memory from the malloc to be available at the new location (unless I missed an API).

However you can do it with file descriptors. You can mmap a PROT_NONE area for the sparse object, then allocate the backing memory into file descriptors, then mmap areas from those file descriptors into the correct places.

But there are limits on file descriptors, you get 1024 soft, or 4096 hard limits by default, which is woefully low for this. Also *all* device memory allocations would need to be fd backed, not just ones going to be used in sparse allocations.

Vulkan has a limit maxMemoryAllocationCount that could be used for this, but setting it to the fd limit is a problem because some fd's are being used by the application and just in general by normal operations, so reporting 4096 for it, is probably going to explode if you only have 3900 of them left.

Also the sparse CTS tests don't respect the maxMemoryAllocationCount anyways :-)

I shall think on this a bit more, please let me know if anyone has any good ideas!

[$] Peer-to-peer DMA

2 év 3 hónap óta
In a plenary session on the first day of the 2023 Linux Storage, Filesystem, Memory-Management and BPF Summit, Stephen Bates led a discussion about peer-to-peer DMA (P2PDMA). The idea is to remove the host system's participation in a transfer of data from one PCIe-connected device to another. The feature was originally aimed at NVMe SSDs so that data could simply be copied directly to and from the storage device without needing to move it to system memory and then from there to somewhere else.
jake

Security updates for Tuesday

2 év 3 hónap óta
Security updates have been issued by Debian (epiphany-browser, python-ipaddress, and sqlparse), Fedora (python-django3 and qemu), Red Hat (apr-util, autotrace, bind, bind9.16, container-tools:4.0, container-tools:rhel8, ctags, curl, device-mapper-multipath, dhcp, edk2, emacs, freeradius:3.0, freerdp, frr, gcc-toolset-12-binutils, git, git-lfs, go-toolset:rhel8, grafana, grafana-pcp, gssntlmssp, Image Builder, kernel, kernel-rt, libarchive, libreswan, libtar, libtiff, mingw-expat, mysql:8.0, net-snmp, pcs, php:7.4, poppler, postgresql-jdbc, python-mako, python27:2.7, python38:3.8 and python38-devel:3.8, python39:3.9 and python39-devel:3.9, samba, sysstat, tigervnc, unbound, virt:rhel and virt-devel:rhel, wayland, webkit2gtk3, xorg-x11-server, and xorg-x11-server-Xwayland), SUSE (dmidecode, postgresql13, prometheus-sap_host_exporter, python-cryptography, rekor, and thunderbird), and Ubuntu (firefox, matrix-synapse, and mysql-8.0).
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Súlyos sebezhetőségeket fedeztek fel a Netgear RAX30 routerekben

2 év 3 hónap óta

A Netgear RAX30 routereket érintően 5 biztonsági hiba került nyilvánosságra, amelyek együttes kihasználásával hitelesítés nélküli távoli kódfuttatás érhető el. “A sikeres kihasználások lehetővé teszik a támadók számára, hogy megfigyeljék az áldozatok internetes tevékenységét, eltérítsék az internetkapcsolatokat, és átirányítsák a forgalmat rosszindulatú webhelyekre, vagy rosszindulatú szoftvereket juttassanak a hálózati forgalomba” – nyilatkozta Uri Katz, a Claroty […]

The post Súlyos sebezhetőségeket fedeztek fel a Netgear RAX30 routerekben first appeared on Nemzeti Kibervédelmi Intézet.

NKI

Az Egyesült Királyság új csalás elleni stratégiát tett közzé

2 év 3 hónap óta

Az Egyesült Királyság kormánya egy új online platformot tervez a – többek között a kibertérben történő – csalások bejelentésére, ezzel megerősítve a Nemzeti Kiberbiztonsági Központ (NCSC) csalások elleni fellépését. Az intézkedések a brit belügyminisztérium által közzétett Csalási Stratégiában olvashatóak, amelyek bevezetésének kezdeti célja, hogy a csalások 2019-es szintjét 2025-ig 10%-al csökkenteni tudják. Az Egyesült Királyságban […]

The post Az Egyesült Királyság új csalás elleni stratégiát tett közzé first appeared on Nemzeti Kibervédelmi Intézet.

NKI

[$] User-space control of memory management

2 év 3 hónap óta
In a remotely presented, memory-management-track session at the 2023 Linux Storage, Filesystem, Memory-Management and BPF Summit, Frank van der Linden pointed out that the line dividing resources controlled by the kernel from those managed by user space has moved back and forth over the years. He is currently interested in making it possible for user space to take more control over the management of memory resources. A proposal was discussed in general terms, but it will require some real scrutiny on its way toward the mainline, if it ever gets there.
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Sourceware becomes an SFC member project

2 év 3 hónap óta
Sourceware.org, which has long played host to many important projects, has announced that it has become a member project of the Software Freedom Conservancy — a move that has been in the works for some time.

Recent discussions have inspired the Sourceware volunteers to think carefully about the future and succession of the leadership for this important hosting project. By joining SFC, Sourceware gains access to strategic advice and governance expertise to recruit new volunteers and raise funds to support work on Sourceware infrastructure.

See this article for more background on those recent discussions.

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[$] Memory overcommit in containerized environments

2 év 3 hónap óta
Overcommitting memory is a longstanding tradition in the Linux world (and beyond); it is rare that an application uses all of the memory allocated to it, so overcommitting can help to improve overall memory utilization. In situations where memory has been overcommitted, though, it may be necessary to respond quickly to ensure that applications have the memory they actually need, even when those needs change. At the 2023 Linux Storage, Filesystem, Memory-Management and BPF Summit, T.J. Alumbaugh (in the room) and Yuanchu Xie (remotely) presented a new mechanism intended to help hosts provide containerized guests with the memory resources they need.
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[$] Live migration of virtual machines over CXL

2 év 3 hónap óta
Virtual-machine hosting can be a fickle business; once a virtual machine has been placed on a physical host, there may arise a desire to move it to a different host. The problem with migrating virtual machines, though, is that there is a period during which the machine is not running; that can be disruptive even if it is brief. At the 2023 Linux Storage, Filesystem, Memory-Management and BPF Summit, Dragan Stancevic, presenting remotely, showed how CXL shared memory can be used to migrate virtual machines with no offline time.
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Security updates for Monday

2 év 3 hónap óta
Security updates have been issued by Debian (golang-websocket, kernel, postgresql-11, and thunderbird), Fedora (firefox, kernel, libreswan, libssh, tcpreplay, and thunderbird), SUSE (dcmtk, gradle, libraw, postgresql12, postgresql13, postgresql14, and postgresql15), and Ubuntu (firefox, nova, and thunderbird).
jake

Figyelem: Aktív kihasználás alatt egy WordPress bővítmény sérülékenysége!

2 év 3 hónap óta

A kihasználási demonstráció (Proof-of-Concept - PoC) nyilvánosságra kerülése után közel 24 órán belül megindultak a WordPress Advanced Custom Fields nevű pluginjának sérülékenységét célzó támadások.

The post Figyelem: Aktív kihasználás alatt egy WordPress bővítmény sérülékenysége! first appeared on Nemzeti Kibervédelmi Intézet.

NKI

[$] 1½ Topics: realtime throttling and user-space adaptive spinning

2 év 3 hónap óta
The Linux CPU scheduler will let realtime tasks hog the CPU to the exclusion of everything else — except when it doesn't. At the 2023 Open Source Summit North America, Joel Fernandes covered the problems with the kernel's realtime throttling mechanism and a couple of potential solutions. As a bonus, since the room was unscheduled for the following slot, attendees were treated to a spontaneous session on adaptive spinning in user space run by André Almeida.
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[$] The future of memory tiering

2 év 3 hónap óta
Memory tiering is the practice of dividing physical memory into separate levels according to its performance characteristics, then allocating that memory in a (hopefully) optimal manner for the workload the system is running. The subject came up repeatedly during the 2023 Linux Storage, Filesystem, Memory-Management and BPF Summit. One session, led by David Rientjes, focused directly on tiering and how it might be better supported by the Linux kernel.
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[$] Memory-management changes for CXL

2 év 3 hónap óta
Kyungsan Kim began his talk at the 2023 Linux Storage, Filesystem, Memory-Management and BPF Summit with a claim that the Compute Express Link (CXL) technology is leading to fundamental changes in computer architecture. The kernel will have to respond with changes of its own, including in its memory-management layer. Drawing on some experience gained at Samsung, Kim had a few suggestions on the form those changes should take — suggestions that ran into some disagreement from other memory-management developers.
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