From mboxrd@z Thu Jan 1 00:00:00 1970 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 1B7423D47D9; Wed, 30 Sep 2026 19:18:33 +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=1790795914; cv=none; b=OQdDOmlO3VBFQciV/f4VaMqjbCbn/JAEBurUPBXbYu8Ln1xPCFwhzwev+NsqZIzZIvhUXvy5ZweGP/+DIPxCyH/Oyor0xsm7oyPoVf6SXGTKoZNblfMzQkfRIfQczqsuvJHZKpowEOM/GaQb4M2PKygak+mqsYcpyJX2eDvxBoo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790795914; c=relaxed/simple; bh=wMrPqBOCwsJ6S1/h3NGfYyhO1WcYjj6w3bfh3sdfapQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aU2r4qBBGPoy7mLb4vuEi0pDEYeKusyPWvAT9SUGRpyvnOO/CYkhbiRT1v+6R6G2w8CQfxiirw37/93ZjaDjLsRxDVTQ9jsK7Z6bhRaCfuTCobs5bdagF/JLaaSaSkkzUcd77Qft7QKa8259CgialTvmP6LEhragVleUvSktvVs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1iefcilg; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1iefcilg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 757D21F000FF; Wed, 30 Sep 2026 19:18:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790795913; bh=kwnCF74JMsizgnaFnpt2PsoChdM1dhzvZQYo3rrvTNU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1iefcilg7/2aFMrShGS6XYskwinNS1yhk+ROvWhHkcdKJd0zka6vvsbt+rmMVFgEz emR/505wIPHpv60ZmtvqWAd0T6A2fa98+DW0Dmstu9jDUGcSAp8eZNFsJtysUJnay/ gOLE0iv2dzZlnEAjFDuXwAljnaztjKyCAPCSKOcQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Norbert Szetei , Zhu Yanjun , Leon Romanovsky , Sasha Levin Subject: [PATCH 6.6 0728/1193] RDMA/rxe: validate access flags before swapping the MRs PD Date: Wed, 30 Sep 2026 17:23:32 +0200 Message-ID: <20260930152450.428126611@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152434.301151190@linuxfoundation.org> References: <20260930152434.301151190@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Norbert Szetei [ Upstream commit ae36a5b609ae79f4de966328b78d2584be9719a4 ] rxe_rereg_user_mr() reassigns mr->ibmr.pd first and only then validates the IB_MR_REREG_ACCESS argument: if (flags & IB_MR_REREG_PD) { rxe_put(old_pd); rxe_get(pd); mr->ibmr.pd = ibpd; } if (flags & IB_MR_REREG_ACCESS) { if (access & ~RXE_ACCESS_SUPPORTED_MR) return ERR_PTR(-EOPNOTSUPP); mr->access = access; } Both flags pass the entry check because RXE_MR_REREG_SUPPORTED is IB_MR_REREG_PD | IB_MR_REREG_ACCESS, so a caller can reach the access check with mr->ibmr.pd already reassigned. mr->ibmr.pd is owned by the core, which adjusts pd->usecnt only on the success path: ib_uverbs_rereg_mr() jumps to put_new_uobj on a driver error without undoing the reassignment, so mr->pd == new_pd while the usecnts still charge the MR to orig_pd. ib_dereg_mr_user() then decrements new_pd, whose count can reach zero while a memory window still references it; uverbs_free_pd() frees the PD on that count alone and rxe_mw_cleanup() writes to freed memory: BUG: KASAN: slab-use-after-free in __rxe_put+0x31/0xa0 Write of size 4 at addr ffff8881301dd690 by task rxe_poc/591 __rxe_put+0x31/0xa0 rxe_mw_cleanup+0x42/0x200 __rxe_cleanup+0x115/0x370 rxe_dealloc_mw+0x4c/0x80 Allocated by task 591: ib_uverbs_alloc_pd+0x258/0x540 Freed by task 591: ib_dealloc_pd_user+0x174/0x210 uverbs_free_pd+0x8d/0xc0 ib_uverbs_dealloc_pd+0x18e/0x1d0 Validate the access flags before mutating any state so the callback either applies every requested change or none. Fixes: 544c7f62cf32 ("RDMA/rxe: Implement rereg_user_mr") Signed-off-by: Norbert Szetei Link: https://patch.msgid.link/46E1D5C0-24BE-4D01-BDB3-634FE09B22C5@doyensec.com Reviewed-by: Zhu Yanjun Signed-off-by: Leon Romanovsky Signed-off-by: Sasha Levin --- drivers/infiniband/sw/rxe/rxe_verbs.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c index 5a9826de59d4c..a7bfa9532d697 100644 --- a/drivers/infiniband/sw/rxe/rxe_verbs.c +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c @@ -1330,19 +1330,20 @@ static struct ib_mr *rxe_rereg_user_mr(struct ib_mr *ibmr, int flags, if (err) return ERR_PTR(err); + if ((flags & IB_MR_REREG_ACCESS) && + (access & ~RXE_ACCESS_SUPPORTED_MR)) { + rxe_err_mr(mr, "access = %#x not supported\n", access); + return ERR_PTR(-EOPNOTSUPP); + } + if (flags & IB_MR_REREG_PD) { rxe_put(old_pd); rxe_get(pd); mr->ibmr.pd = ibpd; } - if (flags & IB_MR_REREG_ACCESS) { - if (access & ~RXE_ACCESS_SUPPORTED_MR) { - rxe_err_mr(mr, "access = %#x not supported\n", access); - return ERR_PTR(-EOPNOTSUPP); - } + if (flags & IB_MR_REREG_ACCESS) mr->access = access; - } return NULL; } -- 2.53.0