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| author | Jeffrey Mitchell <jeffrey.mitchell@starlab.io> | 2020-08-05 20:23:19 +0300 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2020-08-12 16:46:22 +0300 |
| commit | b4487b93545214a9db8cbf32e86411677b0cca21 (patch) | |
| tree | e19a8f9cbb3f0a7540eb9106fe85b6982d07f439 | |
| parent | d474f96104bd4377573526ebae2ee212205a6839 (diff) | |
| download | linux-b4487b93545214a9db8cbf32e86411677b0cca21.tar.xz | |
nfs: Fix getxattr kernel panic and memory overflow
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>
| -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 113e0d6dd3d3..5db240688d4e 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5856,8 +5856,6 @@ 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 388ac520b104..79018938d6b3 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -4166,7 +4166,11 @@ static int decode_attr_security_label(struct xdr_stream *xdr, uint32_t *bitmap, return -EIO; 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; |