--- id: CVE-2025-38727 title: |- In the Linux kernel, the following vulnerability has been resolved: netlink: avoid infinite retry looping in netlink_unicast() netlink_attachskb() checks for the socket's read memory allocation constraints summary: |- In the Linux kernel, the following vulnerability has been resolved: netlink: avoid infinite retry looping in netlink_unicast() netlink_attachskb() checks for the socket's read memory allocation constraints. Firstly, it has: rmem < R… severity: medium cvss: 5.5 cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H' cwe: - CWE-835 vendor: linux product: linux_kernel affected: - 'linux_kernel >= 6.1.146, < 6.1.149' - 'linux_kernel >= 6.6.99, < 6.6.103' - 'linux_kernel >= 6.12.39, < 6.12.43' - 'linux_kernel >= 6.15.7, < 6.15.11' - 'linux_kernel >= 6.16.1, < 6.16.2' - linux_kernel = 5.4.296 - linux_kernel = 5.10.240 - linux_kernel = 5.15.189 - linux_kernel = 6.16 - debian_linux = 11.0 patched: - linux_kernel 6.16.2 published: '2025-09-04' updated: '2026-10-15' sourceUpdated: '2026-10-15T02:17:57.843' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-38727' references: - url: 'https://git.kernel.org/stable/c/346c820ef5135cf062fa3473da955ef8c5fb6929' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/44ddd7b1ae0b7edb2c832eb16798c827a05e58f0' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/47d49fd07f86d1f55ea1083287303d237e9e0922' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/6bee383ff83352a693d03efdf27cdd80742f71b2' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/759dfc7d04bab1b0b86113f1164dc1fec192b859' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/78fcd69d55c5f11d7694c547eca767a1cfd38ec4' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/d42b71a34f6b8a2d5c53df81169b03b8d8b5cf4e' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/e8edc7de688791a337c068693f22e8d8b869df71' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/f324959ad47e62e3cadaffa65d3cff790fb48529' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://cert-portal.siemens.com/productcert/html/ssa-019113.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e - url: 'https://cert-portal.siemens.com/productcert/html/ssa-032379.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e - url: 'https://cert-portal.siemens.com/productcert/html/ssa-082556.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e - url: 'https://cert-portal.siemens.com/productcert/html/ssa-457936.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e tags: - nvd - cve.org epss: 0.00171 epssPercentile: 0.06426 ingestedAt: '2026-09-08T15:33:26.997Z' --- ## Overview In the Linux kernel, the following vulnerability has been resolved: netlink: avoid infinite retry looping in netlink_unicast() netlink_attachskb() checks for the socket's read memory allocation constraints. Firstly, it has: rmem < READ_ONCE(sk->sk_rcvbuf) to check if the just increased rmem value fits into the socket's receive buffer. If not, it proceeds and tries to wait for the memory under: rmem + skb->truesize > READ_ONCE(sk->sk_rcvbuf) The checks don't cover the case when skb->truesize + sk->sk_rmem_alloc is equal to sk->sk_rcvbuf. Thus the function neither successfully accepts these conditions, nor manages to reschedule the task - and is called in retry loop for indefinite time which is caught as: rcu: INFO: rcu_sched self-detected stall on CPU rcu: 0-....: (25999 ticks this GP) idle=ef2/1/0x4000000000000000 softirq=262269/262269 fqs=6212 (t=26000 jiffies g=230833 q=259957) NMI backtrace for cpu 0 CPU: 0 PID: 22 Comm: kauditd Not tainted 5.10.240 #68 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc42 04/01/2014 Call Trace: dump_stack lib/dump_stack.c:120 nmi_cpu_backtrace.cold lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace lib/nmi_backtrace.c:62 rcu_dump_cpu_stacks kernel/rcu/tree_stall.h:335 rcu_sched_clock_irq.cold kernel/rcu/tree.c:2590 update_process_times kernel/time/timer.c:1953 tick_sched_handle kernel/time/tick-sched.c:227 tick_sched_timer kernel/time/tick-sched.c:1399 __hrtimer_run_queues kernel/time/hrtimer.c:1652 hrtimer_interrupt kernel/time/hrtimer.c:1717 __sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113 asm_call_irq_on_stack arch/x86/entry/entry_64.S:808 netlink_attachskb net/netlink/af_netlink.c:1234 netlink_unicast net/netlink/af_netlink.c:1349 kauditd_send_queue kernel/audit.c:776 kauditd_thread kernel/audit.c:897 kthread kernel/kthread.c:328 ret_from_fork arch/x86/entry/entry_64.S:304 Restore the original behavior of the check which commit in Fixes accidentally missed when restructuring the code. Found by Linux Verification Center (linuxtesting.org). ## Affected - `linux_kernel >= 6.1.146, < 6.1.149` - `linux_kernel >= 6.6.99, < 6.6.103` - `linux_kernel >= 6.12.39, < 6.12.43` - `linux_kernel >= 6.15.7, < 6.15.11` - `linux_kernel >= 6.16.1, < 6.16.2` - `linux_kernel = 5.4.296` - `linux_kernel = 5.10.240` - `linux_kernel = 5.15.189` - `linux_kernel = 6.16` - `debian_linux = 11.0` ## Remediation Upgrade past the affected range: - `linux_kernel 6.16.2`