ghsa-8799-vgxh-gh75
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
NFSD: fix race between nfsd registration and exports_proc
As of now nfsd calls create_proc_exports_entry() at start of init_nfsd and cleanup by remove_proc_entry() at last of exit_nfsd.
Which causes kernel OOPs if there is race between below 2 operations: (i) exportfs -r (ii) mount -t nfsd none /proc/fs/nfsd
for 5.4 kernel ARM64:
CPU 1: el1_irq+0xbc/0x180 arch_counter_get_cntvct+0x14/0x18 running_clock+0xc/0x18 preempt_count_add+0x88/0x110 prep_new_page+0xb0/0x220 get_page_from_freelist+0x2d8/0x1778 __alloc_pages_nodemask+0x15c/0xef0 __vmalloc_node_range+0x28c/0x478 __vmalloc_node_flags_caller+0x8c/0xb0 kvmalloc_node+0x88/0xe0 nfsd_init_net+0x6c/0x108 [nfsd] ops_init+0x44/0x170 register_pernet_operations+0x114/0x270 register_pernet_subsys+0x34/0x50 init_nfsd+0xa8/0x718 [nfsd] do_one_initcall+0x54/0x2e0
CPU 2 : Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
PC is at : exports_net_open+0x50/0x68 [nfsd]
Call trace: exports_net_open+0x50/0x68 [nfsd] exports_proc_open+0x2c/0x38 [nfsd] proc_reg_open+0xb8/0x198 do_dentry_open+0x1c4/0x418 vfs_open+0x38/0x48 path_openat+0x28c/0xf18 do_filp_open+0x70/0xe8 do_sys_open+0x154/0x248
Sometimes it crashes at exports_net_open() and sometimes cache_seq_next_rcu().
and same is happening on latest 6.14 kernel as well:
[ 0.000000] Linux version 6.14.0-rc5-next-20250304-dirty ... [ 285.455918] Unable to handle kernel paging request at virtual address 00001f4800001f48 ... [ 285.464902] pc : cache_seq_next_rcu+0x78/0xa4 ... [ 285.469695] Call trace: [ 285.470083] cache_seq_next_rcu+0x78/0xa4 (P) [ 285.470488] seq_read+0xe0/0x11c [ 285.470675] proc_reg_read+0x9c/0xf0 [ 285.470874] vfs_read+0xc4/0x2fc [ 285.471057] ksys_read+0x6c/0xf4 [ 285.471231] __arm64_sys_read+0x1c/0x28 [ 285.471428] invoke_syscall+0x44/0x100 [ 285.471633] el0_svc_common.constprop.0+0x40/0xe0 [ 285.471870] do_el0_svc_compat+0x1c/0x34 [ 285.472073] el0_svc_compat+0x2c/0x80 [ 285.472265] el0t_32_sync_handler+0x90/0x140 [ 285.472473] el0t_32_sync+0x19c/0x1a0 [ 285.472887] Code: f9400885 93407c23 937d7c27 11000421 (f86378a3) [ 285.473422] ---[ end trace 0000000000000000 ]---
It reproduced simply with below script: while [ 1 ] do /exportfs -r done &
while [ 1 ] do insmod /nfsd.ko mount -t nfsd none /proc/fs/nfsd umount /proc/fs/nfsd rmmod nfsd done &
So exporting interfaces to user space shall be done at last and cleanup at first place.
With change there is no Kernel OOPs.
{
"affected": [],
"aliases": [
"CVE-2025-38232"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-07-04T14:15:32Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: fix race between nfsd registration and exports_proc\n\nAs of now nfsd calls create_proc_exports_entry() at start of init_nfsd\nand cleanup by remove_proc_entry() at last of exit_nfsd.\n\nWhich causes kernel OOPs if there is race between below 2 operations:\n(i) exportfs -r\n(ii) mount -t nfsd none /proc/fs/nfsd\n\nfor 5.4 kernel ARM64:\n\nCPU 1:\nel1_irq+0xbc/0x180\narch_counter_get_cntvct+0x14/0x18\nrunning_clock+0xc/0x18\npreempt_count_add+0x88/0x110\nprep_new_page+0xb0/0x220\nget_page_from_freelist+0x2d8/0x1778\n__alloc_pages_nodemask+0x15c/0xef0\n__vmalloc_node_range+0x28c/0x478\n__vmalloc_node_flags_caller+0x8c/0xb0\nkvmalloc_node+0x88/0xe0\nnfsd_init_net+0x6c/0x108 [nfsd]\nops_init+0x44/0x170\nregister_pernet_operations+0x114/0x270\nregister_pernet_subsys+0x34/0x50\ninit_nfsd+0xa8/0x718 [nfsd]\ndo_one_initcall+0x54/0x2e0\n\nCPU 2 :\nUnable to handle kernel NULL pointer dereference at virtual address 0000000000000010\n\nPC is at : exports_net_open+0x50/0x68 [nfsd]\n\nCall trace:\nexports_net_open+0x50/0x68 [nfsd]\nexports_proc_open+0x2c/0x38 [nfsd]\nproc_reg_open+0xb8/0x198\ndo_dentry_open+0x1c4/0x418\nvfs_open+0x38/0x48\npath_openat+0x28c/0xf18\ndo_filp_open+0x70/0xe8\ndo_sys_open+0x154/0x248\n\nSometimes it crashes at exports_net_open() and sometimes cache_seq_next_rcu().\n\nand same is happening on latest 6.14 kernel as well:\n\n[ 0.000000] Linux version 6.14.0-rc5-next-20250304-dirty\n...\n[ 285.455918] Unable to handle kernel paging request at virtual address 00001f4800001f48\n...\n[ 285.464902] pc : cache_seq_next_rcu+0x78/0xa4\n...\n[ 285.469695] Call trace:\n[ 285.470083] cache_seq_next_rcu+0x78/0xa4 (P)\n[ 285.470488] seq_read+0xe0/0x11c\n[ 285.470675] proc_reg_read+0x9c/0xf0\n[ 285.470874] vfs_read+0xc4/0x2fc\n[ 285.471057] ksys_read+0x6c/0xf4\n[ 285.471231] __arm64_sys_read+0x1c/0x28\n[ 285.471428] invoke_syscall+0x44/0x100\n[ 285.471633] el0_svc_common.constprop.0+0x40/0xe0\n[ 285.471870] do_el0_svc_compat+0x1c/0x34\n[ 285.472073] el0_svc_compat+0x2c/0x80\n[ 285.472265] el0t_32_sync_handler+0x90/0x140\n[ 285.472473] el0t_32_sync+0x19c/0x1a0\n[ 285.472887] Code: f9400885 93407c23 937d7c27 11000421 (f86378a3)\n[ 285.473422] ---[ end trace 0000000000000000 ]---\n\nIt reproduced simply with below script:\nwhile [ 1 ]\ndo\n/exportfs -r\ndone \u0026\n\nwhile [ 1 ]\ndo\ninsmod /nfsd.ko\nmount -t nfsd none /proc/fs/nfsd\numount /proc/fs/nfsd\nrmmod nfsd\ndone \u0026\n\nSo exporting interfaces to user space shall be done at last and\ncleanup at first place.\n\nWith change there is no Kernel OOPs.",
"id": "GHSA-8799-vgxh-gh75",
"modified": "2025-07-04T15:31:10Z",
"published": "2025-07-04T15:31:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38232"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2029ca75cdfa6a25716a5a76b751486cce7e3822"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/327011a2bb4f7de9c72b891a96ce8d902828bddf"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f7fb730cac9aafda8b9813b55d04e28a9664d17c"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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