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Vulnerability · Published Mar 12, 2025 · Assigned by Linux

CVE-2025-21852net: Add rx_skb of kfree_skb to raw_tp_null_args[].

Medium 5.5

In plain English

A medium-severity null pointer dereference in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.5Medium
Exploit odds (30 days)0.2%top 87.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: net: Add rx_skb of kfree_skb to raw_tp_null_args[]. Yan Zhai reported a BPF prog could trigger a null-ptr-deref [0] in trace_kfree_skb if the prog does not check if rx_sk is NULL. Commit c53795d48ee8 ("net: add rx_sk to trace_kfree_skb") added rx_sk to trace_kfree_skb, but rx_sk is optional and could be NULL. Let's add kfree_skb to raw_tp_null_args[] to let the BPF verifier validate such a prog and prevent the issue. Now we fail to load such a prog: libbpf: prog 'drop': -- BEGIN PROG LOAD LOG -- 0: R1=ctx() R10=fp0 ; int BPF_PROG(drop, struct sk_buff *skb, void *location, @ kfree_skb_sk_null.bpf.c:21 0: (79) r3 = *(u64 *)(r1 +24) func 'kfree_skb' arg3 has btf_id 5253 type STRUCT 'sock' 1: R1=ctx() R3_w=trusted_ptr_or_null_sock(id=1) ; bpf_printk("sk: %d, %d\n", sk, sk->__sk_common.skc_family); @ kfree_skb_sk_null.bpf.c:24 1: (69) r4 = *(u16 *)(r3 +16) R3 invalid mem access 'trusted_ptr_or_null_' processed 2 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 -- END PROG LOAD LOG -- Note this fix requires commit 838a10bd2ebf ("bpf: Augment raw_tp arguments with PTR_MAYBE_NULL"). [0]: BUG: kernel NULL pointer dereference, address: 0000000000000010 PF: supervisor read access in kernel mode PF: error_code(0x0000) - not-present page PGD 0 P4D 0 PREEMPT SMP RIP: 0010:bpf_prog_5e21a6db8fcff1aa_drop+0x10/0x2d Call Trace: <TASK> ? __die+0x1f/0x60 ? page_fault_oops+0x148/0x420 ? search_bpf_extables+0x5b/0x70 ? fixup_exception+0x27/0x2c0 ? exc_page_fault+0x75/0x170 ? asm_exc_page_fault+0x22/0x30 ? bpf_prog_5e21a6db8fcff1aa_drop+0x10/0x2d bpf_trace_run4+0x68/0xd0 ? unix_stream_connect+0x1f4/0x6f0 sk_skb_reason_drop+0x90/0x120 unix_stream_connect+0x1f4/0x6f0 __sys_connect+0x7f/0xb0 __x64_sys_connect+0x14/0x20 do_syscall_64+0x47/0xc30 entry_SYSCALL_64_after_hwframe+0x4b/0x53

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:13linux6.12.17-1DEBIAN-CVE-2025-21852
Debian:14linux6.12.17-1DEBIAN-CVE-2025-21852
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2025-21852
Ubuntu:24.04:LTSlinux-azure-6.116.11.0-1015.15~24.04.1UBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2025-21852
Ubuntu:24.04:LTSlinux-gcp-6.116.11.0-1015.15~24.04.1UBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2025-21852
Ubuntu:24.04:LTSlinux-hwe-6.116.11.0-26.26~24.04.1UBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2025-21852
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.116.11.0-1014.15~24.04.1UBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2025-21852
Ubuntu:24.04:LTSlinux-nvidia-6.116.11.0-1010.10UBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2025-21852
Ubuntu:24.04:LTSlinux-oem-6.116.11.0-1022.22UBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2025-21852
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-21852
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2025-21852
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2025-21852

Affected products (as reported)

VendorProductVersions
Linux Linux c53795d48ee8f385c6a9e394651e7ee914baaeba – before f579afacd0a66971fc8481f30d2d377e230a8342c53795d48ee8f385c6a9e394651e7ee914baaeba – before 4dba79c1e7aad6620bbb707b6c4459380fd90860c53795d48ee8f385c6a9e394651e7ee914baaeba – before 5da7e15fb5a12e78de974d8908f348e279922ce9
Linux Linux 6.11

Weakness: CWE-476 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References