In the Linux kernel, the following vulnerability has been resolved:

nfs: Fix KMSAN warning in decodegetfattrattrs()

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 decodegetfattrattrs+0x2d6d/0x2f90 decodegetfattrattrs+0x2d6d/0x2f90 decodegetfattrgeneric+0x806/0xb00 nfs4xdrdecgetattr+0x1de/0x240 rpcauthunwraprespdecode+0xab/0x100 rpcauthunwrapresp+0x95/0xc0 calldecode+0x4ff/0xb50 _rpcexecute+0x57b/0x19d0 rpcexecute+0x368/0x5e0 rpcruntask+0xcfe/0xee0 nfs4procgetattr+0x5b5/0x990 _nfsrevalidateinode+0x477/0xd00 nfsaccessgetcached+0x1021/0x1cc0 nfsdoaccess+0x9f/0xae0 nfspermission+0x1e4/0x8c0 inodepermission+0x356/0x6c0 linkpathwalk+0x958/0x1330 pathlookupat+0xce/0x6b0 filenamelookup+0x23e/0x770 vfsstatx+0xe7/0x970 vfsfstatat+0x1f2/0x2c0 _sesysnewfstatat+0x67/0x880 _x64sysnewfstatat+0xbd/0x120 x64syscall+0x1826/0x3cf0 dosyscall64+0xd0/0x1b0 entrySYSCALL64afterhwframe+0x77/0x7f

The KMSAN warning is triggered in decodegetfattrattrs(), when calling decodeattrmdsthreshold(). It appears that fattr->mdsthreshold is not initialized.

Fix the issue by initializing fattr->mdsthreshold to NULL in nfsfattrinit().