nfsd: fix potential lease memory leak in nfs4_setlease (415b96c5) · Commits · 戴 / test

It's unlikely to ever occur, but if there were already a lease set on the file then we could end up getting back a different pointer on a successful setlease attempt than the one we allocated. If that happens, the one we allocated could leak. In practice, I don't think this will happen due to the fact that we only try to set up the lease once per nfs4_file, but this error handling is a bit more correct given the current lease API. Cc: J. Bruce Fields <bfields@fieldses.org> Signed-off-by:

Jeff Layton <jlayton@primarydata.com> Reviewed-by:

Christoph Hellwig <hch@lst.de>

fs/nfsd/nfs4state.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -3781,7 +3781,7 @@ static struct file_lock nfs4_alloc_init_lease(struct nfs4_file fp, int flag)
		static int nfs4_setlease(struct nfs4_delegation *dp)
		{
		struct nfs4_file *fp = dp->dl_stid.sc_file;
		struct file_lock *fl;
		struct file_lock fl, ret;
		struct file *filp;
		int status = 0;

		@@ -3795,11 +3795,14 @@ static int nfs4_setlease(struct nfs4_delegation *dp)
		return -EBADF;
		}
		fl->fl_file = filp;
		status = vfs_setlease(filp, fl->fl_type, &fl);
		ret = fl;
		status = vfs_setlease(filp, fl->fl_type, &ret);
		if (status) {
		locks_free_lock(fl);
		goto out_fput;
		}
		if (ret != fl)
		locks_free_lock(fl);
		spin_lock(&state_lock);
		spin_lock(&fp->fi_lock);
		/* Did the lease get broken before we took the lock? */

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