CVE-2024-36937 — xdp: use flags field to disambiguate broadcast redirect

Affected: Linux

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

xdp: use flags field to disambiguate broadcast redirect

When redirecting a packet using XDP, the bpf_redirect_map() helper will set up the redirect destination information in struct bpf_redirect_info (using the __bpf_xdp_redirect_map() helper function), and the xdp_do_redirect() function will read this information after the XDP program returns and pass the frame on to the right redirect destination.

When using the BPF_F_BROADCAST flag to do multicast redirect to a whole map, __bpf_xdp_redirect_map() sets the 'map' pointer in struct bpf_redirect_info to point to the destination map to be broadcast. And xdp_do_redirect() reacts to the value of this map pointer to decide whether it's dealing with a broadcast or a single-value redirect. However, if the destination map is being destroyed before xdp_do_redirect() is called, the map pointer will be cleared out (by bpf_clear_redirect_map()) without waiting for any XDP programs to stop running. This causes xdp_do_redirect() to think that the redirect was to a single target, but the target pointer is also NULL (since broadcast redirects don't have a single target), so this causes a crash when a NULL pointer is passed to dev_map_enqueue().

To fix this, change xdp_do_redirect() to react directly to the presence of the BPF_F_BROADCAST flag in the 'flags' value in struct bpf_redirect_info to disambiguate between a single-target and a broadcast redirect. And only read…

USN-6949-1 — linux, linux-aws, linux-gcp, linux-gke, linux-ibm, linux-nvidia, linux-nvidia-6.8 vulnerabilities

Affected: Ubuntu:22.04:LTS: linux-nvidia-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-nvidia

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; - M68K architecture; - OpenRISC architecture; - PowerPC architecture; - RISC-V architecture; - x86 architecture; - Block layer subsystem; - Accessibility subsystem; - Bluetooth drivers; - Clock framework and drivers; - CPU frequency scaling framework; - Hardware crypto device drivers; - DMA engine subsystem; - DPLL subsystem; - FireWire subsystem; - EFI core; - Qualcomm firmware drivers; - GPIO subsystem; - GPU drivers; - Microsoft Hyper-V drivers; - InfiniBand drivers; - IOMMU subsystem; - IRQ chip drivers; - Macintosh device drivers; - Multiple devices driver; - Media drivers; - EEPROM drivers; - MMC subsystem; - Network drivers; - STMicroelectronics network drivers; - Device tree and open firmware driver; - HiSilicon SoC PMU drivers; - PHY drivers; - Pin controllers subsystem; - Remote Processor subsystem; - S/390 drivers; - SCSI drivers; - SPI subsystem; - Media staging drivers; - Thermal drivers; - Userspace I/O drivers; - USB subsystem; - DesignWare USB3 driver; - ACRN Hypervisor Service Module driver; - Virtio drivers; - 9P distributed file system; - BTRFS file system; - eCrypt file system; - EROFS file system; - File systems infrastructure; - GF…

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CVE-2024-36937 — xdp: use flags field to disambiguate broadcast redirect

USN-6949-1 — linux, linux-aws, linux-gcp, linux-gke, linux-ibm, linux-nvidia, linux-nvidia-6.8 vulnerabilities