Описание
In the Linux kernel, the following vulnerability has been resolved: nfs: Fix KMSAN warning in decode_getfattr_attrs() Fix the following KMSAN warning: CPU: 1 UID: 0 PID: 7651 Comm: cp Tainted: G B Tainted: [B]=BAD_PAGE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009)
=====================================================
BUG: KMSAN: uninit-value in decode_getfattr_attrs+0x2d6d/0x2f90
decode_getfattr_attrs+0x2d6d/0x2f90
decode_getfattr_generic+0x806/0xb00
nfs4_xdr_dec_getattr+0x1de/0x240
rpcauth_unwrap_resp_decode+0xab/0x100
rpcauth_unwrap_resp+0x95/0xc0
call_decode+0x4ff/0xb50
__rpc_execute+0x57b/0x19d0
rpc_execute+0x368/0x5e0
rpc_run_task+0xcfe/0xee0
nfs4_proc_getattr+0x5b5/0x990
__nfs_revalidate_inode+0x477/0xd00
nfs_access_get_cached+0x1021/0x1cc0
nfs_do_access+0x9f/0xae0
nfs_permission+0x1e4/0x8c0
inode_permission+0x356/0x6c0
link_path_walk+0x958/0x1330
path_lookupat+0xce/0x6b0
filename_lookup+0x23e/0x770
vfs_statx+0xe7/0x970
vfs_fstatat+0x1f2/0x2c0
__se_sys_newfstatat+0x67/0x880
__x64_sys_newfstatat+0xbd/0x120
x64_sys_call+0x1826/0x3cf0
do_syscall_64+0xd0/0x1b0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The KMSAN warning is triggered in decode_getfattr_attrs(), when calling
decode_attr_mdsthreshold(). It appears that fattr->mdsthreshold is not
initialized.
Fix the issue by initializing fattr->mdsthreshold to NULL in
nfs_fattr_init().
A flaw was found in the Linux kernel's NFS (Network File System) implementation. When querying file attributes, the kernel fails to properly initialize internal attribute data structures before parsing server responses. A local user can exploit this flaw by interacting with files on an NFS mount, triggering an uninitialized memory access that may lead to a kernel crash and a Denial of Service (DoS).
Меры по смягчению последствий
To reduce exposure on systems where NFS file sharing is not required, prevent autoloading of the NFS client kernel modules:
- Create a configuration file in
/etc/modprobe.d/to disable loading of the modules:
echo "install nfs /bin/true" > /etc/modprobe.d/disable-nfs.conf
echo "install nfsv4 /bin/true" >> /etc/modprobe.d/disable-nfs.conf
- If the modules are currently loaded in the running kernel, attempt to unload them:
modprobe -r nfsv4 nfs
Caveats: Blacklisting these modules prevents the system from mounting NFS shares. If filesystems are actively mounted or services are utilizing NFS, a system reboot will be required for the configuration to take effect.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Out of support scope | ||
| Red Hat Enterprise Linux 8 | kernel | Will not fix | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Will not fix | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred |
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Дополнительная информация
Статус:
EPSS
3.3 Low
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: nfs: Fix KMSAN warning in decode_getfattr_attrs() Fix the following KMSAN warning: CPU: 1 UID: 0 PID: 7651 Comm: cp Tainted: G B Tainted: [B]=BAD_PAGE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009) ===================================================== ===================================================== BUG: KMSAN: uninit-value in decode_getfattr_attrs+0x2d6d/0x2f90 decode_getfattr_attrs+0x2d6d/0x2f90 decode_getfattr_generic+0x806/0xb00 nfs4_xdr_dec_getattr+0x1de/0x240 rpcauth_unwrap_resp_decode+0xab/0x100 rpcauth_unwrap_resp+0x95/0xc0 call_decode+0x4ff/0xb50 __rpc_execute+0x57b/0x19d0 rpc_execute+0x368/0x5e0 rpc_run_task+0xcfe/0xee0 nfs4_proc_getattr+0x5b5/0x990 __nfs_revalidate_inode+0x477/0xd00 nfs_access_get_cached+0x1021/0x1cc0 nfs_do_access+0x9f/0xae0 nfs_permission+0x1e4/0x8c0 inode_permission+0x356/0x6c0 link_path_walk+0x958/0x1330 path_lookupat+0xce/0x6b0 filename_lookup+0x23e/0x770 vfs_statx+0xe7/0...
In the Linux kernel, the following vulnerability has been resolved: nfs: Fix KMSAN warning in decode_getfattr_attrs() Fix the following KMSAN warning: CPU: 1 UID: 0 PID: 7651 Comm: cp Tainted: G B Tainted: [B]=BAD_PAGE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009) ===================================================== ===================================================== BUG: KMSAN: uninit-value in decode_getfattr_attrs+0x2d6d/0x2f90 decode_getfattr_attrs+0x2d6d/0x2f90 decode_getfattr_generic+0x806/0xb00 nfs4_xdr_dec_getattr+0x1de/0x240 rpcauth_unwrap_resp_decode+0xab/0x100 rpcauth_unwrap_resp+0x95/0xc0 call_decode+0x4ff/0xb50 __rpc_execute+0x57b/0x19d0 rpc_execute+0x368/0x5e0 rpc_run_task+0xcfe/0xee0 nfs4_proc_getattr+0x5b5/0x990 __nfs_revalidate_inode+0x477/0xd00 nfs_access_get_cached+0x1021/0x1cc0 nfs_do_access+0x9f/0xae0 nfs_permission+0x1e4/0x8c0 inode_permission+0x356/0x6c0 link_path_walk+0x958/0x1330 path_lookupat+0xce/0x6b0 filename_lookup+0x23e/0x77
In the Linux kernel, the following vulnerability has been resolved: n ...
In the Linux kernel, the following vulnerability has been resolved: nfs: Fix KMSAN warning in decode_getfattr_attrs() Fix the following KMSAN warning: CPU: 1 UID: 0 PID: 7651 Comm: cp Tainted: G B Tainted: [B]=BAD_PAGE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009) ===================================================== ===================================================== BUG: KMSAN: uninit-value in decode_getfattr_attrs+0x2d6d/0x2f90 decode_getfattr_attrs+0x2d6d/0x2f90 decode_getfattr_generic+0x806/0xb00 nfs4_xdr_dec_getattr+0x1de/0x240 rpcauth_unwrap_resp_decode+0xab/0x100 rpcauth_unwrap_resp+0x95/0xc0 call_decode+0x4ff/0xb50 __rpc_execute+0x57b/0x19d0 rpc_execute+0x368/0x5e0 rpc_run_task+0xcfe/0xee0 nfs4_proc_getattr+0x5b5/0x990 __nfs_revalidate_inode+0x477/0xd00 nfs_access_get_cached+0x1021/0x1cc0 nfs_do_access+0x9f/0xae0 nfs_permission+0x1e4/0x8c0 inode_permission+0x356/0x6c0 link_path_walk+0x958/0x1330 path_lookupat+0xce/0x6b0 filename_lookup+0x23e/0...
EPSS
3.3 Low
CVSS3