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authorChuck Lever <chuck.lever@oracle.com>2022-01-31 19:01:53 +0100
committerChuck Lever <chuck.lever@oracle.com>2022-02-09 15:22:48 +0100
commite6faac3f58c7c4176b66f63def17a34232a17b0e (patch)
tree858960b30b99c269b728075ea860bc8d77abfc81 /fs
parentNFSD: Fix the behavior of READ near OFFSET_MAX (diff)
downloadlinux-e6faac3f58c7c4176b66f63def17a34232a17b0e.tar.xz
linux-e6faac3f58c7c4176b66f63def17a34232a17b0e.zip
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/nfsd/vfs.c4
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;