An update for kernel is now available for openEuler-22.03-LTS-SP3 Security Advisory openeuler-security@openeuler.org openEuler security committee openEuler-SA-2025-2469 Final 1.0 1.0 2025-10-17 Initial 2025-10-17 2025-10-17 openEuler SA Tool V1.0 2025-10-17 kernel security update An update for kernel is now available for openEuler-22.03-LTS-SP3 The Linux Kernel, the operating system core itself. Security Fix(es): In the Linux kernel, the following vulnerability has been resolved: NFSD: Protect against send buffer overflow in NFSv2 READ Since before the git era, NFSD has conserved the number of pages held by each nfsd thread by combining the RPC receive and send buffers into a single array of pages. This works because there are no cases where an operation needs a large RPC Call message and a large RPC Reply at the same time. Once an RPC Call has been received, svc_process() updates svc_rqst::rq_res to describe the part of rq_pages that can be used for constructing the Reply. This means that the send buffer (rq_res) shrinks when the received RPC record containing the RPC Call is large. A client can force this shrinkage on TCP by sending a correctly- formed RPC Call header contained in an RPC record that is excessively large. The full maximum payload size cannot be constructed in that case.(CVE-2022-50410) In the Linux kernel, the following vulnerability has been resolved: media: az6007: Fix null-ptr-deref in az6007_i2c_xfer() In az6007_i2c_xfer, msg is controlled by user. When msg[i].buf is null and msg[i].len is zero, former checks on msg[i].buf would be passed. Malicious data finally reach az6007_i2c_xfer. If accessing msg[i].buf[0] without sanity check, null ptr deref would happen. We add check on msg[i].len to prevent crash. Similar commit: commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")(CVE-2023-53220) In the Linux kernel, the following vulnerability has been resolved: kobject: Add sanity check for kset->kobj.ktype in kset_register() When I register a kset in the following way: static struct kset my_kset; kobject_set_name(&my_kset.kobj, "my_kset"); ret = kset_register(&my_kset); A null pointer dereference exception is occurred: [ 4453.568337] Unable to handle kernel NULL pointer dereference at \ virtual address 0000000000000028 ... ... [ 4453.810361] Call trace: [ 4453.813062] kobject_get_ownership+0xc/0x34 [ 4453.817493] kobject_add_internal+0x98/0x274 [ 4453.822005] kset_register+0x5c/0xb4 [ 4453.825820] my_kobj_init+0x44/0x1000 [my_kset] ... ... Because I didn't initialize my_kset.kobj.ktype. According to the description in Documentation/core-api/kobject.rst: - A ktype is the type of object that embeds a kobject. Every structure that embeds a kobject needs a corresponding ktype. So add sanity check to make sure kset->kobj.ktype is not NULL.(CVE-2023-53480) In the Linux kernel, the following vulnerability has been resolved: virtio-mmio: don't break lifecycle of vm_dev vm_dev has a separate lifecycle because it has a 'struct device' embedded. Thus, having a release callback for it is correct. Allocating the vm_dev struct with devres totally breaks this protection, though. Instead of waiting for the vm_dev release callback, the memory is freed when the platform_device is removed. Resulting in a use-after-free when finally the callback is to be called. To easily see the problem, compile the kernel with CONFIG_DEBUG_KOBJECT_RELEASE and unbind with sysfs. The fix is easy, don't use devres in this case. Found during my research about object lifetime problems.(CVE-2023-53515) In the Linux kernel, the following vulnerability has been resolved: net: usbnet: Fix WARNING in usbnet_start_xmit/usb_submit_urb The syzbot fuzzer identified a problem in the usbnet driver: usb 1-1: BOGUS urb xfer, pipe 3 != type 1 WARNING: CPU: 0 PID: 754 at drivers/usb/core/urb.c:504 usb_submit_urb+0xed6/0x1880 drivers/usb/core/urb.c:504 Modules linked in: CPU: 0 PID: 754 Comm: kworker/0:2 Not tainted 6.4.0-rc7-syzkaller-00014-g692b7dc87ca6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: mld mld_ifc_work RIP: 0010:usb_submit_urb+0xed6/0x1880 drivers/usb/core/urb.c:504 Code: 7c 24 18 e8 2c b4 5b fb 48 8b 7c 24 18 e8 42 07 f0 fe 41 89 d8 44 89 e1 4c 89 ea 48 89 c6 48 c7 c7 a0 c9 fc 8a e8 5a 6f 23 fb <0f> 0b e9 58 f8 ff ff e8 fe b3 5b fb 48 81 c5 c0 05 00 00 e9 84 f7 RSP: 0018:ffffc9000463f568 EFLAGS: 00010086 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff88801eb28000 RSI: ffffffff814c03b7 RDI: 0000000000000001 RBP: ffff8881443b7190 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000003 R13: ffff88802a77cb18 R14: 0000000000000003 R15: ffff888018262500 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556a99c15a18 CR3: 0000000028c71000 CR4: 0000000000350ef0 Call Trace: <TASK> usbnet_start_xmit+0xfe5/0x2190 drivers/net/usb/usbnet.c:1453 __netdev_start_xmit include/linux/netdevice.h:4918 [inline] netdev_start_xmit include/linux/netdevice.h:4932 [inline] xmit_one net/core/dev.c:3578 [inline] dev_hard_start_xmit+0x187/0x700 net/core/dev.c:3594 ... This bug is caused by the fact that usbnet trusts the bulk endpoint addresses its probe routine receives in the driver_info structure, and it does not check to see that these endpoints actually exist and have the expected type and directions. The fix is simply to add such a check.(CVE-2023-53548) In the Linux kernel, the following vulnerability has been resolved: tracing: Limit access to parser->buffer when trace_get_user failed When the length of the string written to set_ftrace_filter exceeds FTRACE_BUFF_MAX, the following KASAN alarm will be triggered: BUG: KASAN: slab-out-of-bounds in strsep+0x18c/0x1b0 Read of size 1 at addr ffff0000d00bd5ba by task ash/165 CPU: 1 UID: 0 PID: 165 Comm: ash Not tainted 6.16.0-g6bcdbd62bd56-dirty Hardware name: linux,dummy-virt (DT) Call trace: show_stack+0x34/0x50 (C) dump_stack_lvl+0xa0/0x158 print_address_description.constprop.0+0x88/0x398 print_report+0xb0/0x280 kasan_report+0xa4/0xf0 __asan_report_load1_noabort+0x20/0x30 strsep+0x18c/0x1b0 ftrace_process_regex.isra.0+0x100/0x2d8 ftrace_regex_release+0x484/0x618 __fput+0x364/0xa58 ____fput+0x28/0x40 task_work_run+0x154/0x278 do_notify_resume+0x1f0/0x220 el0_svc+0xec/0xf0 el0t_64_sync_handler+0xa0/0xe8 el0t_64_sync+0x1ac/0x1b0 The reason is that trace_get_user will fail when processing a string longer than FTRACE_BUFF_MAX, but not set the end of parser->buffer to 0. Then an OOB access will be triggered in ftrace_regex_release-> ftrace_process_regex->strsep->strpbrk. We can solve this problem by limiting access to parser->buffer when trace_get_user failed.(CVE-2025-39683) In the Linux kernel, the following vulnerability has been resolved: vxlan: Fix NPD in {arp,neigh}_reduce() when using nexthop objects When the "proxy" option is enabled on a VXLAN device, the device will suppress ARP requests and IPv6 Neighbor Solicitation messages if it is able to reply on behalf of the remote host. That is, if a matching and valid neighbor entry is configured on the VXLAN device whose MAC address is not behind the "any" remote (0.0.0.0 / ::). The code currently assumes that the FDB entry for the neighbor's MAC address points to a valid remote destination, but this is incorrect if the entry is associated with an FDB nexthop group. This can result in a NPD [1][3] which can be reproduced using [2][4]. Fix by checking that the remote destination exists before dereferencing it. [1] BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] CPU: 4 UID: 0 PID: 365 Comm: arping Not tainted 6.17.0-rc2-virtme-g2a89cb21162c #2 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014 RIP: 0010:vxlan_xmit+0xb58/0x15f0 [...] Call Trace: <TASK> dev_hard_start_xmit+0x5d/0x1c0 __dev_queue_xmit+0x246/0xfd0 packet_sendmsg+0x113a/0x1850 __sock_sendmsg+0x38/0x70 __sys_sendto+0x126/0x180 __x64_sys_sendto+0x24/0x30 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x4b/0x53 [2] #!/bin/bash ip address add 192.0.2.1/32 dev lo ip nexthop add id 1 via 192.0.2.2 fdb ip nexthop add id 10 group 1 fdb ip link add name vx0 up type vxlan id 10010 local 192.0.2.1 dstport 4789 proxy ip neigh add 192.0.2.3 lladdr 00:11:22:33:44:55 nud perm dev vx0 bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10 arping -b -c 1 -s 192.0.2.1 -I vx0 192.0.2.3 [3] BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] CPU: 13 UID: 0 PID: 372 Comm: ndisc6 Not tainted 6.17.0-rc2-virtmne-g6ee90cb26014 #3 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1v996), BIOS 1.17.0-4.fc41 04/01/2x014 RIP: 0010:vxlan_xmit+0x803/0x1600 [...] Call Trace: <TASK> dev_hard_start_xmit+0x5d/0x1c0 __dev_queue_xmit+0x246/0xfd0 ip6_finish_output2+0x210/0x6c0 ip6_finish_output+0x1af/0x2b0 ip6_mr_output+0x92/0x3e0 ip6_send_skb+0x30/0x90 rawv6_sendmsg+0xe6e/0x12e0 __sock_sendmsg+0x38/0x70 __sys_sendto+0x126/0x180 __x64_sys_sendto+0x24/0x30 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f383422ec77 [4] #!/bin/bash ip address add 2001:db8:1::1/128 dev lo ip nexthop add id 1 via 2001:db8:1::1 fdb ip nexthop add id 10 group 1 fdb ip link add name vx0 up type vxlan id 10010 local 2001:db8:1::1 dstport 4789 proxy ip neigh add 2001:db8:1::3 lladdr 00:11:22:33:44:55 nud perm dev vx0 bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10 ndisc6 -r 1 -s 2001:db8:1::1 -w 1 2001:db8:1::3 vx0(CVE-2025-39850) An update for kernel is now available for openEuler-22.03-LTS-SP3. openEuler Security has rated this update as having a security impact of high. A Common Vunlnerability Scoring System(CVSS)base score,which gives a detailed severity rating, is available for each vulnerability from the CVElink(s) in the References section. High kernel https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2025-2469 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2022-50410 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2023-53220 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2023-53480 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2023-53515 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2023-53548 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2025-39683 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2025-39850 https://nvd.nist.gov/vuln/detail/CVE-2022-50410 https://nvd.nist.gov/vuln/detail/CVE-2023-53220 https://nvd.nist.gov/vuln/detail/CVE-2023-53480 https://nvd.nist.gov/vuln/detail/CVE-2023-53515 https://nvd.nist.gov/vuln/detail/CVE-2023-53548 https://nvd.nist.gov/vuln/detail/CVE-2025-39683 https://nvd.nist.gov/vuln/detail/CVE-2025-39850 openEuler-22.03-LTS-SP3 kernel-5.10.0-285.0.0.187.oe2203sp3.src.rpm kernel-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm kernel-debuginfo-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm kernel-debugsource-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm kernel-devel-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm kernel-headers-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm kernel-source-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm kernel-tools-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm kernel-tools-debuginfo-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm kernel-tools-devel-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm perf-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm perf-debuginfo-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm python3-perf-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm python3-perf-debuginfo-5.10.0-285.0.0.187.oe2203sp3.x86_64.rpm kernel-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm kernel-debuginfo-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm kernel-debugsource-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm kernel-devel-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm kernel-headers-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm kernel-source-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm kernel-tools-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm kernel-tools-debuginfo-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm kernel-tools-devel-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm perf-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm perf-debuginfo-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm python3-perf-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm python3-perf-debuginfo-5.10.0-285.0.0.187.oe2203sp3.aarch64.rpm In the Linux kernel, the following vulnerability has been resolved: NFSD: Protect against send buffer overflow in NFSv2 READ Since before the git era, NFSD has conserved the number of pages held by each nfsd thread by combining the RPC receive and send buffers into a single array of pages. This works because there are no cases where an operation needs a large RPC Call message and a large RPC Reply at the same time. Once an RPC Call has been received, svc_process() updates svc_rqst::rq_res to describe the part of rq_pages that can be used for constructing the Reply. This means that the send buffer (rq_res) shrinks when the received RPC record containing the RPC Call is large. A client can force this shrinkage on TCP by sending a correctly- formed RPC Call header contained in an RPC record that is excessively large. The full maximum payload size cannot be constructed in that case. 2025-10-17 CVE-2022-50410 openEuler-22.03-LTS-SP3 High 7.1 AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:H kernel security update 2025-10-17 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2025-2469 In the Linux kernel, the following vulnerability has been resolved: media: az6007: Fix null-ptr-deref in az6007_i2c_xfer() In az6007_i2c_xfer, msg is controlled by user. When msg[i].buf is null and msg[i].len is zero, former checks on msg[i].buf would be passed. Malicious data finally reach az6007_i2c_xfer. If accessing msg[i].buf[0] without sanity check, null ptr deref would happen. We add check on msg[i].len to prevent crash. Similar commit: commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()") 2025-10-17 CVE-2023-53220 openEuler-22.03-LTS-SP3 Medium 5.5 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H kernel security update 2025-10-17 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2025-2469 In the Linux kernel, the following vulnerability has been resolved: kobject: Add sanity check for kset->kobj.ktype in kset_register() When I register a kset in the following way: static struct kset my_kset; kobject_set_name(&my_kset.kobj, "my_kset"); ret = kset_register(&my_kset); A null pointer dereference exception is occurred: [ 4453.568337] Unable to handle kernel NULL pointer dereference at \ virtual address 0000000000000028 ... ... [ 4453.810361] Call trace: [ 4453.813062] kobject_get_ownership+0xc/0x34 [ 4453.817493] kobject_add_internal+0x98/0x274 [ 4453.822005] kset_register+0x5c/0xb4 [ 4453.825820] my_kobj_init+0x44/0x1000 [my_kset] ... ... Because I didn't initialize my_kset.kobj.ktype. According to the description in Documentation/core-api/kobject.rst: - A ktype is the type of object that embeds a kobject. Every structure that embeds a kobject needs a corresponding ktype. So add sanity check to make sure kset->kobj.ktype is not NULL. 2025-10-17 CVE-2023-53480 openEuler-22.03-LTS-SP3 High 7.0 AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H kernel security update 2025-10-17 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2025-2469 In the Linux kernel, the following vulnerability has been resolved: virtio-mmio: don't break lifecycle of vm_dev vm_dev has a separate lifecycle because it has a 'struct device' embedded. Thus, having a release callback for it is correct. Allocating the vm_dev struct with devres totally breaks this protection, though. Instead of waiting for the vm_dev release callback, the memory is freed when the platform_device is removed. Resulting in a use-after-free when finally the callback is to be called. To easily see the problem, compile the kernel with CONFIG_DEBUG_KOBJECT_RELEASE and unbind with sysfs. The fix is easy, don't use devres in this case. Found during my research about object lifetime problems. 2025-10-17 CVE-2023-53515 openEuler-22.03-LTS-SP3 Medium 4.4 AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H kernel security update 2025-10-17 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2025-2469 In the Linux kernel, the following vulnerability has been resolved: net: usbnet: Fix WARNING in usbnet_start_xmit/usb_submit_urb The syzbot fuzzer identified a problem in the usbnet driver: usb 1-1: BOGUS urb xfer, pipe 3 != type 1 WARNING: CPU: 0 PID: 754 at drivers/usb/core/urb.c:504 usb_submit_urb+0xed6/0x1880 drivers/usb/core/urb.c:504 Modules linked in: CPU: 0 PID: 754 Comm: kworker/0:2 Not tainted 6.4.0-rc7-syzkaller-00014-g692b7dc87ca6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: mld mld_ifc_work RIP: 0010:usb_submit_urb+0xed6/0x1880 drivers/usb/core/urb.c:504 Code: 7c 24 18 e8 2c b4 5b fb 48 8b 7c 24 18 e8 42 07 f0 fe 41 89 d8 44 89 e1 4c 89 ea 48 89 c6 48 c7 c7 a0 c9 fc 8a e8 5a 6f 23 fb <0f> 0b e9 58 f8 ff ff e8 fe b3 5b fb 48 81 c5 c0 05 00 00 e9 84 f7 RSP: 0018:ffffc9000463f568 EFLAGS: 00010086 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff88801eb28000 RSI: ffffffff814c03b7 RDI: 0000000000000001 RBP: ffff8881443b7190 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000003 R13: ffff88802a77cb18 R14: 0000000000000003 R15: ffff888018262500 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556a99c15a18 CR3: 0000000028c71000 CR4: 0000000000350ef0 Call Trace: <TASK> usbnet_start_xmit+0xfe5/0x2190 drivers/net/usb/usbnet.c:1453 __netdev_start_xmit include/linux/netdevice.h:4918 [inline] netdev_start_xmit include/linux/netdevice.h:4932 [inline] xmit_one net/core/dev.c:3578 [inline] dev_hard_start_xmit+0x187/0x700 net/core/dev.c:3594 ... This bug is caused by the fact that usbnet trusts the bulk endpoint addresses its probe routine receives in the driver_info structure, and it does not check to see that these endpoints actually exist and have the expected type and directions. The fix is simply to add such a check. 2025-10-17 CVE-2023-53548 openEuler-22.03-LTS-SP3 Medium 4.3 AV:P/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H kernel security update 2025-10-17 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2025-2469 In the Linux kernel, the following vulnerability has been resolved: tracing: Limit access to parser->buffer when trace_get_user failed When the length of the string written to set_ftrace_filter exceeds FTRACE_BUFF_MAX, the following KASAN alarm will be triggered: BUG: KASAN: slab-out-of-bounds in strsep+0x18c/0x1b0 Read of size 1 at addr ffff0000d00bd5ba by task ash/165 CPU: 1 UID: 0 PID: 165 Comm: ash Not tainted 6.16.0-g6bcdbd62bd56-dirty Hardware name: linux,dummy-virt (DT) Call trace: show_stack+0x34/0x50 (C) dump_stack_lvl+0xa0/0x158 print_address_description.constprop.0+0x88/0x398 print_report+0xb0/0x280 kasan_report+0xa4/0xf0 __asan_report_load1_noabort+0x20/0x30 strsep+0x18c/0x1b0 ftrace_process_regex.isra.0+0x100/0x2d8 ftrace_regex_release+0x484/0x618 __fput+0x364/0xa58 ____fput+0x28/0x40 task_work_run+0x154/0x278 do_notify_resume+0x1f0/0x220 el0_svc+0xec/0xf0 el0t_64_sync_handler+0xa0/0xe8 el0t_64_sync+0x1ac/0x1b0 The reason is that trace_get_user will fail when processing a string longer than FTRACE_BUFF_MAX, but not set the end of parser->buffer to 0. Then an OOB access will be triggered in ftrace_regex_release-> ftrace_process_regex->strsep->strpbrk. We can solve this problem by limiting access to parser->buffer when trace_get_user failed. 2025-10-17 CVE-2025-39683 openEuler-22.03-LTS-SP3 Medium 4.4 AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H kernel security update 2025-10-17 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2025-2469 In the Linux kernel, the following vulnerability has been resolved: vxlan: Fix NPD in {arp,neigh}_reduce() when using nexthop objects When the "proxy" option is enabled on a VXLAN device, the device will suppress ARP requests and IPv6 Neighbor Solicitation messages if it is able to reply on behalf of the remote host. That is, if a matching and valid neighbor entry is configured on the VXLAN device whose MAC address is not behind the "any" remote (0.0.0.0 / ::). The code currently assumes that the FDB entry for the neighbor's MAC address points to a valid remote destination, but this is incorrect if the entry is associated with an FDB nexthop group. This can result in a NPD [1][3] which can be reproduced using [2][4]. Fix by checking that the remote destination exists before dereferencing it. [1] BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] CPU: 4 UID: 0 PID: 365 Comm: arping Not tainted 6.17.0-rc2-virtme-g2a89cb21162c #2 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014 RIP: 0010:vxlan_xmit+0xb58/0x15f0 [...] Call Trace: <TASK> dev_hard_start_xmit+0x5d/0x1c0 __dev_queue_xmit+0x246/0xfd0 packet_sendmsg+0x113a/0x1850 __sock_sendmsg+0x38/0x70 __sys_sendto+0x126/0x180 __x64_sys_sendto+0x24/0x30 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x4b/0x53 [2] #!/bin/bash ip address add 192.0.2.1/32 dev lo ip nexthop add id 1 via 192.0.2.2 fdb ip nexthop add id 10 group 1 fdb ip link add name vx0 up type vxlan id 10010 local 192.0.2.1 dstport 4789 proxy ip neigh add 192.0.2.3 lladdr 00:11:22:33:44:55 nud perm dev vx0 bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10 arping -b -c 1 -s 192.0.2.1 -I vx0 192.0.2.3 [3] BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] CPU: 13 UID: 0 PID: 372 Comm: ndisc6 Not tainted 6.17.0-rc2-virtmne-g6ee90cb26014 #3 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1v996), BIOS 1.17.0-4.fc41 04/01/2x014 RIP: 0010:vxlan_xmit+0x803/0x1600 [...] Call Trace: <TASK> dev_hard_start_xmit+0x5d/0x1c0 __dev_queue_xmit+0x246/0xfd0 ip6_finish_output2+0x210/0x6c0 ip6_finish_output+0x1af/0x2b0 ip6_mr_output+0x92/0x3e0 ip6_send_skb+0x30/0x90 rawv6_sendmsg+0xe6e/0x12e0 __sock_sendmsg+0x38/0x70 __sys_sendto+0x126/0x180 __x64_sys_sendto+0x24/0x30 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f383422ec77 [4] #!/bin/bash ip address add 2001:db8:1::1/128 dev lo ip nexthop add id 1 via 2001:db8:1::1 fdb ip nexthop add id 10 group 1 fdb ip link add name vx0 up type vxlan id 10010 local 2001:db8:1::1 dstport 4789 proxy ip neigh add 2001:db8:1::3 lladdr 00:11:22:33:44:55 nud perm dev vx0 bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10 ndisc6 -r 1 -s 2001:db8:1::1 -w 1 2001:db8:1::3 vx0 2025-10-17 CVE-2025-39850 openEuler-22.03-LTS-SP3 Medium 5.5 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H kernel security update 2025-10-17 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2025-2469