CVE-2024-57982 — xfrm: state: fix out-of-bounds read during lookup

Affected: Linux

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

xfrm: state: fix out-of-bounds read during lookup

lookup and resize can run in parallel.

The xfrm_state_hash_generation seqlock ensures a retry, but the hash functions can observe a hmask value that is too large for the new hlist array.

rehash does: rcu_assign_pointer(net->xfrm.state_bydst, ndst) [..] net->xfrm.state_hmask = nhashmask;

While state lookup does: h = xfrm_dst_hash(net, daddr, saddr, tmpl->reqid, encap_family); hlist_for_each_entry_rcu(x, net->xfrm.state_bydst + h, bydst) {

This is only safe in case the update to state_bydst is larger than net->xfrm.xfrm_state_hmask (or if the lookup function gets serialized via state spinlock again).

Fix this by prefetching state_hmask and the associated pointers. The xfrm_state_hash_generation seqlock retry will ensure that the pointer and the hmask will be consistent.

The existing helpers, like xfrm_dst_hash(), are now unsafe for RCU side, add lockdep assertions to document that they are only safe for insert side.

xfrm_state_lookup_byaddr() uses the spinlock rather than RCU. AFAICS this is an oversight from back when state lookup was converted to RCU, this lock should be replaced with RCU in a future patch.

USN-7521-1 — linux, linux-azure, linux-azure-6.11, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-oem-6.11, linux-raspi, linux-rea…

Affected: Ubuntu:24.04:LTS: linux-azure-6.11, Ubuntu:24.04:LTS: linux-gcp-6.11, Ubuntu:24.04:LTS: linux-hwe-6.11, Ubuntu:24.04:LTS: linux-oem-6.11

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; - x86 architecture; - Block layer subsystem; - Serial ATA and Parallel ATA drivers; - Drivers core; - Network block device driver; - Bluetooth drivers; - Character device driver; - TPM device driver; - Clock framework and drivers; - Hardware crypto device drivers; - FireWire subsystem; - EFI core; - Qualcomm firmware drivers; - GPIO subsystem; - GPU drivers; - HID subsystem; - I2C subsystem; - I3C subsystem; - InfiniBand drivers; - Input Device (Mouse) drivers; - IOMMU subsystem; - Multiple devices driver; - Media drivers; - NVIDIA Tegra memory controller driver; - Fastrpc Driver; - Network drivers; - Operating Performance Points (OPP) driver; - PCI subsystem; - x86 platform drivers; - PPS (Pulse Per Second) driver; - PTP clock framework; - Remote Processor subsystem; - Real Time Clock drivers; - S/390 drivers; - SCSI subsystem; - QCOM SoC drivers; - SPI subsystem; - Media staging drivers; - Trusted Execution Environment drivers; - TTY drivers; - UFS subsystem; - USB Device Class drivers; - USB core drivers; - USB Gadget drivers; - USB Host Controller drivers; - Framebuffer layer; - File systems infrastructure; - BTRFS file system; - Ceph distributed fi…

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CVE-2024-57982 — xfrm: state: fix out-of-bounds read during lookup

USN-7521-1 — linux, linux-azure, linux-azure-6.11, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-oem-6.11, linux-raspi, linux-rea…