cbcvebase.
CVE-2024-56703
published 2024-12-28

CVE-2024-56703: In the Linux kernel, the following vulnerability has been resolved: ipv6: Fix soft lockups in fib6_select_path under high next hop churn Soft lockups have been…

PriorityP422medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.21%
11.0th percentile
In the Linux kernel, the following vulnerability has been resolved: ipv6: Fix soft lockups in fib6_select_path under high next hop churn Soft lockups have been observed on a cluster of Linux-based edge routers located in a highly dynamic environment. Using the `bird` service, these routers continuously update BGP-advertised routes due to frequently changing nexthop destinations, while also managing significant IPv6 traffic. The lockups occur during the traversal of the multipath circular linked-list in the `fib6_select_path` function, particularly while iterating through the siblings in the list. The issue typically arises when the nodes of the linked list are unexpectedly deleted concurrently on a different core—indicated by their 'next' and 'previous' elements pointing back to the node itself and their reference count dropping to zero. This results in an infinite loop, leading to a soft lockup that triggers a system panic via the watchdog timer. Apply RCU primitives in the problematic code sections to resolve the issue. Where necessary, update the references to fib6_siblings to annotate or use the RCU APIs. Include a test script that reproduces the issue. The script periodically updates the routing table while generating a heavy load of outgoing IPv6 traffic through multiple iperf3 clients. It consistently induces infinite soft lockups within a couple of minutes. Kernel log: 0 [ffffbd13003e8d30] machine_kexec at ffffffff8ceaf3eb 1 [ffffbd13003e8d90] __crash_kexec at ffffffff8d0120e3 2 [ffffbd13003e8e58] panic at ffffffff8cef65d4 3 [ffffbd13003e8ed8] watchdog_timer_fn at ffffffff8d05cb03 4 [ffffbd13003e8f08] __hrtimer_run_queues at ffffffff8cfec62f 5 [ffffbd13003e8f70] hrtimer_interrupt at ffffffff8cfed756 6 [ffffbd13003e8fd0] __sysvec_apic_timer_interrupt at ffffffff8cea01af 7 [ffffbd13003e8ff0] sysvec_apic_timer_interrupt at ffffffff8df1b83d -- -- 8 [ffffbd13003d3708] asm_sysvec_apic_timer_interrupt at ffffffff8e000ecb [exception RIP: fib6_select_path+299]

Affected

22 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.128-1 (bookworm)linux 6.1.128-1 (bookworm)
debianlinux-6.1< linux 6.1.128-1 (bookworm)linux 6.1.128-1 (bookworm)
linuxlinux
linuxlinux>= 66f5d6ce53e665477d2a33e8f539d4fa4ca81c83 < d0ec61c9f3583b76aebdbb271f5c0d3fcccd48b2d0ec61c9f3583b76aebdbb271f5c0d3fcccd48b2
linuxlinux>= 66f5d6ce53e665477d2a33e8f539d4fa4ca81c83 < 52da02521ede55fb86546c3fffd9377b3261b91f52da02521ede55fb86546c3fffd9377b3261b91f
linuxlinux>= 66f5d6ce53e665477d2a33e8f539d4fa4ca81c83 < 11edcd026012ac18acee0f1514db3ed1b160fc6f11edcd026012ac18acee0f1514db3ed1b160fc6f
linuxlinux>= 66f5d6ce53e665477d2a33e8f539d4fa4ca81c83 < 34a949e7a0869dfa31a40416d2a56973fae1807b34a949e7a0869dfa31a40416d2a56973fae1807b
linuxlinux>= 66f5d6ce53e665477d2a33e8f539d4fa4ca81c83 < d9ccb18f83ea2bb654289b6ecf014fd267cc988bd9ccb18f83ea2bb654289b6ecf014fd267cc988b
linuxlinux_kernel>= 0 < 6.1.128-16.1.128-1
linuxlinux_kernel>= 0 < 6.12.3-16.12.3-1
linuxlinux_kernel>= 0 < 6.12.3-16.12.3-1
linuxlinux_kernel>= 0 < 6.8.0-58.606.8.0-58.60
linuxlinux_kernel>= 0 < 6.11.0-18.186.11.0-18.18
linuxlinux_kernel>= 4.15 < 6.1.1286.1.128
linuxlinux_kernel>= 6.12 < 6.12.26.12.2
linuxlinux_kernel>= 6.2 < 6.6.756.6.75
linuxlinux_kernel>= 6.7 < 6.11.116.11.11
msrcazl3_kernel_6.6.64.2-9_on_azure_linux_3.0
msrcazl3_kernel_6.6.78.1-3_on_azure_linux_3.0
msrccbl2_kernel_5.15.186.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.200.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.202.1-1_on_cbl_mariner_2.0

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv8.8HIGH
vendor_ubuntu8.8HIGH
vendor_debian5.5MEDIUM
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
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