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| author | Jeffrey Mitchell <jeffrey.mitchell@starlab.io> | 2020-08-05 12:23:19 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-21 11:05:38 +0200 |
| commit | a906b868953a9c9bba44649a8fe760e818dd7224 (patch) | |
| tree | 2d8477d2658b63811ad68d368a89baac3e8ed973 | |
| parent | c08be09b2c1c5389f1d24677b595822ac7a75a21 (diff) | |
| download | linux-stable-a906b868953a9c9bba44649a8fe760e818dd7224.tar.gz linux-stable-a906b868953a9c9bba44649a8fe760e818dd7224.tar.bz2 linux-stable-a906b868953a9c9bba44649a8fe760e818dd7224.zip | |
nfs: Fix getxattr kernel panic and memory overflow
[ Upstream commit b4487b93545214a9db8cbf32e86411677b0cca21 ]
Move the buffer size check to decode_attr_security_label() before memcpy()
Only call memcpy() if the buffer is large enough
Fixes: aa9c2669626c ("NFS: Client implementation of Labeled-NFS")
Signed-off-by: Jeffrey Mitchell <jeffrey.mitchell@starlab.io>
[Trond: clean up duplicate test of label->len != 0]
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/nfs/nfs4proc.c | 2 | ||||
| -rw-r--r-- | fs/nfs/nfs4xdr.c | 6 |
2 files changed, 5 insertions, 3 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 05cb68ca1ba1..1ef75b1deffa 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5603,8 +5603,6 @@ static int _nfs4_get_security_label(struct inode *inode, void *buf, return ret; if (!(fattr.valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL)) return -ENOENT; - if (buflen < label.len) - return -ERANGE; return 0; } diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index c4cf0192d7bb..0a5cae8f8aff 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -4280,7 +4280,11 @@ static int decode_attr_security_label(struct xdr_stream *xdr, uint32_t *bitmap, goto out_overflow; if (len < NFS4_MAXLABELLEN) { if (label) { - memcpy(label->label, p, len); + if (label->len) { + if (label->len < len) + return -ERANGE; + memcpy(label->label, p, len); + } label->len = len; label->pi = pi; label->lfs = lfs; |