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| author | Chuck Lever <chuck.lever@oracle.com> | 2022-01-31 13:01:53 -0500 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2022-02-09 09:22:48 -0500 |
| commit | e6faac3f58c7c4176b66f63def17a34232a17b0e (patch) | |
| tree | 858960b30b99c269b728075ea860bc8d77abfc81 | |
| parent | 0cb4d23ae08c48f6bf3c29a8e5c4a74b8388b960 (diff) | |
NFSD: Fix ia_size underflow
iattr::ia_size is a loff_t, which is a signed 64-bit type. NFSv3 and
NFSv4 both define file size as an unsigned 64-bit type. Thus there
is a range of valid file size values an NFS client can send that is
already larger than Linux can handle.
Currently decode_fattr4() dumps a full u64 value into ia_size. If
that value happens to be larger than S64_MAX, then ia_size
underflows. I'm about to fix up the NFSv3 behavior as well, so let's
catch the underflow in the common code path: nfsd_setattr().
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
| -rw-r--r-- | fs/nfsd/vfs.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 99c2b9dfbb10..0cccceb105e7 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -435,6 +435,10 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, .ia_size = iap->ia_size, }; + host_err = -EFBIG; + if (iap->ia_size < 0) + goto out_unlock; + host_err = notify_change(&init_user_ns, dentry, &size_attr, NULL); if (host_err) goto out_unlock; |