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 [...
4.10.0-14.16~16.04.14.10.0-19.21~16.04.14.10.0-20.22~16.04.14.10.0-21.23~16.04.14.10.0-22.24~16.04.14.10.0-24.28~16.04.14.10.0-26.30~16.04.14.11.0-13.19~16.04.14.11.0-14.20~16.04.14.13.0-16.19~16.04.3+13 more5.0.0-1021.24~18.04.15.0.0-1022.25~18.04.15.0.0-1023.26~18.04.15.0.0-1024.27~18.04.15.0.0-1025.285.0.0-1027.305.3.0-1016.17~18.04.15.3.0-1017.18~18.04.15.3.0-1019.21~18.04.15.3.0-1023.25~18.04.15.3.0-1028.30~18.04.15.3.0-1030.32~18.04.15.3.0-1032.34~18.04.25.3.0-1033.355.3.0-1034.365.3.0-1035.374.15.0-1002.24.15.0-1003.34.15.0-1004.44.15.0-1008.84.15.0-1009.94.15.0-1012.124.15.0-1013.134.15.0-1014.144.15.0-1018.184.15.0-1019.19+34 more5.3.0-1007.8~18.04.15.3.0-1008.9~18.04.15.3.0-1009.10~18.04.15.3.0-1010.11~18.04.15.3.0-1012.13~18.04.15.3.0-1013.14~18.04.15.3.0-1016.17~18.04.15.3.0-1018.19~18.04.15.3.0-1019.20~18.04.15.3.0-1020.21~18.04.1+6 more4.18.0-1006.6~18.04.14.18.0-1007.7~18.04.14.18.0-1008.8~18.04.15.0.0-1012.12~18.04.24.15.0-1001.14.15.0-1003.34.15.0-1005.54.15.0-1006.64.15.0-1008.84.15.0-1009.94.15.0-1010.104.15.0-1014.144.15.0-1015.154.15.0-1017.18+28 more5.3.0-1008.9~18.04.15.3.0-1009.10~18.04.15.3.0-1010.11~18.04.15.3.0-1012.13~18.04.15.3.0-1014.15~18.04.15.3.0-1016.17~18.04.15.3.0-1017.18~18.04.15.3.0-1018.19~18.04.15.3.0-1020.22~18.04.15.3.0-1026.28~18.04.1+3 more4.15.0-1030.324.15.0-1032.344.15.0-1033.354.15.0-1034.364.15.0-1036.384.15.0-1037.394.15.0-1040.424.15.0-1041.434.15.0-1042.444.15.0-1044.46+23 more5.4.0-1025.25~18.04.15.4.0-1027.28~18.04.15.4.0-1029.31~18.04.15.4.0-1030.32~18.04.15.4.0-1032.34~18.04.15.4.0-1033.35~18.04.15.4.0-1035.37~18.04.15.4.0-1036.38~18.04.15.4.0-1037.39~18.04.15.4.0-1039.41~18.04.1+27 moreExploitability
AV:LAC:HPR:LUI:NScope
S:UImpact
C:NI:NA:HCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H