5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
commit dc270d7159699ad6d11decadfce9633f0f71c1db upstream.
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().
Cc: stable@xxxxxxxxxxxxxxx # v3.5.x
Fixes: 88034c3d88c2 ("NFSv4.1 mdsthreshold attribute xdr")
Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
Signed-off-by: Anna Schumaker <anna.schumaker@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfs/inode.c | 1 +
1 file changed, 1 insertion(+)
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1494,6 +1494,7 @@ void nfs_fattr_init(struct nfs_fattr *fa
fattr->gencount = nfs_inc_attr_generation_counter();
fattr->owner_name = NULL;
fattr->group_name = NULL;
+ fattr->mdsthreshold = NULL;
}
EXPORT_SYMBOL_GPL(nfs_fattr_init);
