Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3880C3CF942 for ; Sun, 6 Sep 2026 13:34:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788701698; cv=none; b=RSWu4KrH3pP401dbc8ODcV5AwjN9d7/1JcZOXhBw4vTnA6LdnhgHPr78PLozE090kmH3xTKrnS07jtF1AnVpO0ducAnHJTWtTPvf7TKAhm2LZjFMN41Q1Ei+owpzP4ngV6T6wxgGa+cOLApg0ZXnTwuW5JKNXWu0q58vU1uKPPc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788701698; c=relaxed/simple; bh=U+EgqV7lsWcOfI6ORZEM4hfPb6ESHwqo8z2/IcapdzE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XBvUL/hbM64KBo17Pv421moN3bwsc0Hd9/Z2PzHNkjWNiNxaQVfsrzKNpq1IK/uuobfmnEgN/5p2YseLDW577Xf8LWQ5b8sM+NISzgrZmuCSkbNyiZhXZ//npDzLtSKAEqpEqLKF2TZFz493Yeto2PhgP1Zo1MyI9nXx8HoJKu8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TOjM8Lzf; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TOjM8Lzf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D9B81F00A3D; Sun, 6 Sep 2026 13:34:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788701697; bh=30nND69hmPNaD+qlUjTVj7FKwbGT6mDmRe7i1QgrRfI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TOjM8LzfZx1+zpL6BgUbFm94Sgxvq8z5iN5FcllR9Vu8IobUh2rOaSxiffwR3K1Gy iI27e275ZIFb/5DNF+4hZqUAThavh556ESQI4YOT3ywMdRxL6op3m+QK3PBWDY/G0o oQsApIXUvKMJflDxTw11vIElvBz7mIrlksJ3Iep6+UbKHyGWNSIBQe4AfsaKofS/P3 w0akRqlW+YEsFx+Ve8X8ZSgPoz50V2PgedT4Q8bhNqO0KaJM0dkFV5QgzSLPyOpIVd 8OkdMystkymJsU2e5epYFCPbrCCANvXxVo2X8+QSWGQCoSjGaA7y/Ra94YF2OnVFsV c9abJWyqRujHg== From: Sasha Levin To: stable@vger.kernel.org Cc: Jeff Layton , Chuck Lever , Sasha Levin Subject: [PATCH 5.10.y 2/2] nfsd: fix stale s2s_cp_stateids IDR entry for async COPY Date: Sun, 6 Sep 2026 09:34:54 -0400 Message-ID: <20260906133454.899083-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260906133454.899083-1-sashal@kernel.org> References: <2026090322-excavate-aside-0c00@gregkh> <20260906133454.899083-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jeff Layton [ Upstream commit d0beaee498e11880e72826026db0e9c9890fc114 ] For an async COPY, nfsd4_copy() called nfs4_init_copy_state() before dup_copy_fields(), so the s2s_cp_stateids IDR was pointed at &u->copy->cp_stateid -- memory in the per-rqstp COMPOUND buffer that is reused by the next request. dup_copy_fields() copies only the value into async_copy, so the IDR slot dangled at the transient buffer for the whole background copy. Any IDR walker then dereferences reused request memory: the laundromat reads cs_type from it and, if the bytes look like an expired NFS4_COPYNOTIFY_STID, follows into refcount_dec()/idr_remove()/kfree() on garbage; manage_cpntf_state() has the same exposure via idr_find(). Duplicate the fields first, then register the stateid on the stable async_copy. result->cb_stateid is unchanged. Fixes: e0639dc5805a ("NFSD introduce async copy feature") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260710-nfsd-testing-v3-3-a0ff7db6aa3e@kernel.org Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- fs/nfsd/nfs4proc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 63a4825dd15f3..2652e60f0f5a7 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1800,11 +1800,12 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, async_copy->cp_src = kmalloc(sizeof(*async_copy->cp_src), GFP_KERNEL); if (!async_copy->cp_src) goto out_dec_async_copy_err; - if (!nfs4_init_copy_state(nn, copy)) + dup_copy_fields(copy, async_copy); + + if (!nfs4_init_copy_state(nn, async_copy)) goto out_dec_async_copy_err; - memcpy(&result->cb_stateid, ©->cp_stateid.cs_stid, + memcpy(&result->cb_stateid, &async_copy->cp_stateid.cs_stid, sizeof(result->cb_stateid)); - dup_copy_fields(copy, async_copy); if ((READ_ONCE(copy->nf_dst->nf_file->f_mode) & FMODE_NOCMTIME) != 0) async_copy->attr_update = true; -- 2.53.0