CVE-2023-53141 in Linux
Summary
by MITRE • 05/02/2025
In the Linux kernel, the following vulnerability has been resolved:
ila: do not generate empty messages in ila_xlat_nl_cmd_get_mapping()
ila_xlat_nl_cmd_get_mapping() generates an empty skb, triggerring a recent sanity check [1].
Instead, return an error code, so that user space can get it.
[1]
skb_assert_len WARNING: CPU: 0 PID: 5923 at include/linux/skbuff.h:2527 skb_assert_len include/linux/skbuff.h:2527 [inline]
WARNING: CPU: 0 PID: 5923 at include/linux/skbuff.h:2527 __dev_queue_xmit+0x1bc0/0x3488 net/core/dev.c:4156 Modules linked in: CPU: 0 PID: 5923 Comm: syz-executor269 Not tainted 6.2.0-syzkaller-18300-g2ebd1fbb946d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : skb_assert_len include/linux/skbuff.h:2527 [inline]
pc : __dev_queue_xmit+0x1bc0/0x3488 net/core/dev.c:4156 lr : skb_assert_len include/linux/skbuff.h:2527 [inline]
lr : __dev_queue_xmit+0x1bc0/0x3488 net/core/dev.c:4156 sp : ffff80001e0d6c40 x29: ffff80001e0d6e60 x28: dfff800000000000 x27: ffff0000c86328c0 x26: dfff800000000000 x25: ffff0000c8632990 x24: ffff0000c8632a00 x23: 0000000000000000 x22: 1fffe000190c6542 x21: ffff0000c8632a10 x20: ffff0000c8632a00 x19: ffff80001856e000 x18: ffff80001e0d5fc0 x17: 0000000000000000 x16: ffff80001235d16c x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000001 x11: ff80800008353a30 x10: 0000000000000000 x9 : 21567eaf25bfb600 x8 : 21567eaf25bfb600 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff80001e0d6558 x4 : ffff800015c74760 x3 : ffff800008596744 x2 : 0000000000000001 x1 : 0000000100000000 x0 : 000000000000000e Call trace: skb_assert_len include/linux/skbuff.h:2527 [inline]
__dev_queue_xmit+0x1bc0/0x3488 net/core/dev.c:4156 dev_queue_xmit include/linux/netdevice.h:3033 [inline]
__netlink_deliver_tap_skb net/netlink/af_netlink.c:307 [inline]
__netlink_deliver_tap+0x45c/0x6f8 net/netlink/af_netlink.c:325 netlink_deliver_tap+0xf4/0x174 net/netlink/af_netlink.c:338 __netlink_sendskb net/netlink/af_netlink.c:1283 [inline]
netlink_sendskb+0x6c/0x154 net/netlink/af_netlink.c:1292 netlink_unicast+0x334/0x8d4 net/netlink/af_netlink.c:1380 nlmsg_unicast include/net/netlink.h:1099 [inline]
genlmsg_unicast include/net/genetlink.h:433 [inline]
genlmsg_reply include/net/genetlink.h:443 [inline]
ila_xlat_nl_cmd_get_mapping+0x620/0x7d0 net/ipv6/ila/ila_xlat.c:493 genl_family_rcv_msg_doit net/netlink/genetlink.c:968 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]
genl_rcv_msg+0x938/0xc1c net/netlink/genetlink.c:1065 netlink_rcv_skb+0x214/0x3c4 net/netlink/af_netlink.c:2574 genl_rcv+0x38/0x50 net/netlink/genetlink.c:1076 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x800/0xae0 net/netlink/af_netlink.c:1942 sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg net/socket.c:734 [inline]
____sys_sendmsg+0x558/0x844 net/socket.c:2479 ___sys_sendmsg net/socket.c:2533 [inline]
__sys_sendmsg+0x26c/0x33c net/socket.c:2562 __do_sys_sendmsg net/socket.c:2571 [inline]
__se_sys_sendmsg net/socket.c:2569 [inline]
__arm64_sys_sendmsg+0x80/0x94 net/socket.c:2569 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 irq event stamp: 136484 hardirqs last enabled at (136483): [<ffff800008350244>] __up_console_sem+0x60/0xb4 kernel/printk/printk.c:345
hardirqs last disabled at (136484): [<ffff800012358d60>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (136418): [<ffff800008020ea8>] softirq_ha
---truncated---
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Analysis
by VulDB Data Team • 01/31/2026
The vulnerability identified as CVE-2023-53141 resides within the Linux kernel's implementation of the ILA (IP Layer Aggregation) module, specifically within the ila_xlat_nl_cmd_get_mapping() function. This flaw manifests as the generation of empty network packets, or skbs, which trigger a recently introduced sanity check mechanism in the kernel. The issue arises from the function's inability to properly handle cases where no valid mapping data is available, leading to the creation of an empty skb that subsequently fails kernel validation routines. The technical root cause lies in the improper error handling logic within the ILA translation module, which fails to return appropriate error codes to user-space applications when mapping information cannot be retrieved or generated.
The operational impact of this vulnerability extends beyond simple kernel crashes or instability, as it represents a potential denial-of-service condition that can be triggered through network-based interactions with the ILA subsystem. When the ila_xlat_nl_cmd_get_mapping() function attempts to send an empty skb through the netlink communication channel, the kernel's skb_assert_len function raises a critical warning, indicating that an invalid packet structure has been generated. This scenario typically occurs when user-space applications query for ILA mappings through the generic netlink interface, and the kernel cannot provide meaningful data, yet still attempts to transmit an empty packet rather than properly signaling the failure condition. The stack trace demonstrates the execution path from user-space socket operations through netlink message handling, ultimately reaching the kernel's network device queueing mechanism where the empty skb fails validation.
This vulnerability aligns with CWE-457, which describes the use of uninitialized or invalid data structures, and potentially relates to CWE-119, concerning improper restriction of operations within a memory buffer. From an ATT&CK perspective, this flaw could be leveraged by adversaries to perform denial-of-service attacks against systems running affected Linux kernels, potentially targeting network services that rely on ILA functionality for IP layer aggregation. The vulnerability also intersects with T1499.004, which covers network disruption techniques, as it could be used to disrupt network communication by causing kernel panics or service unavailability. The improper handling of empty skbs in kernel space represents a classic example of insufficient input validation and error handling, which can lead to system instability and potential information disclosure or privilege escalation depending on the broader context of the kernel attack surface.
Mitigation strategies for CVE-2023-53141 primarily involve applying the kernel patch that modifies the ila_xlat_nl_cmd_get_mapping() function to return appropriate error codes instead of generating empty skbs. System administrators should prioritize updating their kernel versions to include the fix, particularly in environments where ILA functionality is actively used or where systems may be exposed to untrusted network traffic. Additionally, monitoring for kernel warnings related to skb_assert_len and network communication failures can help detect exploitation attempts. Network segmentation and access control measures should be implemented to limit exposure to potentially malicious queries targeting the ILA subsystem. Organizations should also consider disabling ILA functionality if it is not required for their network operations, as this provides an additional layer of defense against potential exploitation of this and similar vulnerabilities.