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Rocky Linux: CVE-2024-26906: kernel-rt (Multiple Advisories)

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Rocky Linux: CVE-2024-26906: kernel-rt (Multiple Advisories)

Severity
4
CVSS
(AV:L/AC:M/Au:N/C:P/I:P/A:P)
Published
04/17/2024
Created
07/16/2024
Added
07/16/2024
Modified
07/16/2024

Description

In the Linux kernel, the following vulnerability has been resolved: x86/mm: Disallow vsyscall page read for copy_from_kernel_nofault() When trying to use copy_from_kernel_nofault() to read vsyscall page through a bpf program, the following oops was reported: BUG: unable to handle page fault for address: ffffffffff600000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 3231067 P4D 3231067 PUD 3233067 PMD 3235067 PTE 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 20390 Comm: test_progs ...... 6.7.0+ #58 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...... RIP: 0010:copy_from_kernel_nofault+0x6f/0x110 ...... Call Trace: <TASK> ? copy_from_kernel_nofault+0x6f/0x110 bpf_probe_read_kernel+0x1d/0x50 bpf_prog_2061065e56845f08_do_probe_read+0x51/0x8d trace_call_bpf+0xc5/0x1c0 perf_call_bpf_enter.isra.0+0x69/0xb0 perf_syscall_enter+0x13e/0x200 syscall_trace_enter+0x188/0x1c0 do_syscall_64+0xb5/0xe0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 </TASK> ...... ---[ end trace 0000000000000000 ]--- The oops is triggered when: 1) A bpf program uses bpf_probe_read_kernel() to read from the vsyscall page and invokes copy_from_kernel_nofault() which in turn calls __get_user_asm(). 2) Because the vsyscall page address is not readable from kernel space, a page fault exception is triggered accordingly. 3) handle_page_fault() considers the vsyscall page address as a user space address instead of a kernel space address. This results in the fix-up setup by bpf not being applied and a page_fault_oops() is invoked due to SMAP. Considering handle_page_fault() has already considered the vsyscall page address as a userspace address, fix the problem by disallowing vsyscall page read for copy_from_kernel_nofault().

Solution(s)

  • rocky-upgrade-bpftool
  • rocky-upgrade-bpftool-debuginfo
  • rocky-upgrade-kernel
  • rocky-upgrade-kernel-abi-stablelists
  • rocky-upgrade-kernel-core
  • rocky-upgrade-kernel-cross-headers
  • rocky-upgrade-kernel-debug
  • rocky-upgrade-kernel-debug-core
  • rocky-upgrade-kernel-debug-debuginfo
  • rocky-upgrade-kernel-debug-devel
  • rocky-upgrade-kernel-debug-modules
  • rocky-upgrade-kernel-debug-modules-extra
  • rocky-upgrade-kernel-debuginfo
  • rocky-upgrade-kernel-debuginfo-common-aarch64
  • rocky-upgrade-kernel-debuginfo-common-x86_64
  • rocky-upgrade-kernel-devel
  • rocky-upgrade-kernel-doc
  • rocky-upgrade-kernel-headers
  • rocky-upgrade-kernel-modules
  • rocky-upgrade-kernel-modules-extra
  • rocky-upgrade-kernel-rt
  • rocky-upgrade-kernel-rt-core
  • rocky-upgrade-kernel-rt-debug
  • rocky-upgrade-kernel-rt-debug-core
  • rocky-upgrade-kernel-rt-debug-debuginfo
  • rocky-upgrade-kernel-rt-debug-devel
  • rocky-upgrade-kernel-rt-debug-kvm
  • rocky-upgrade-kernel-rt-debug-modules
  • rocky-upgrade-kernel-rt-debug-modules-extra
  • rocky-upgrade-kernel-rt-debuginfo
  • rocky-upgrade-kernel-rt-debuginfo-common-x86_64
  • rocky-upgrade-kernel-rt-devel
  • rocky-upgrade-kernel-rt-kvm
  • rocky-upgrade-kernel-rt-modules
  • rocky-upgrade-kernel-rt-modules-extra
  • rocky-upgrade-kernel-tools
  • rocky-upgrade-kernel-tools-debuginfo
  • rocky-upgrade-kernel-tools-libs
  • rocky-upgrade-kernel-tools-libs-devel
  • rocky-upgrade-perf
  • rocky-upgrade-perf-debuginfo
  • rocky-upgrade-python3-perf
  • rocky-upgrade-python3-perf-debuginfo

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