From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793208801; b=rlswKxQdZUuYAyNG9w4/B97gsrn6RJWoYWJZQSNmQ5RuK++u8Z6ZibBvlUJan6IpaFSa n/hKDVCA4rqnaWg4uQOQgsdR96oxoROFcd8LFhmYT59qQUhayjgqlj4e94HrWn1TQXmrC O+Hw1bx7X0UuMjXBG70H9raHZ6E/DxZOcCekSco3GWPsBywQ2VbIJVqfa5D6allGuSXZg ZqQr1LwhoTIXEj03u7lo3icWIqVVzKTxHs1Zi0WCoYEurTmLZWGHWzpb3Hm85d4nRsb0l OKYsqncL58iZ3aLXxFkMu0WWgDpi+YlvlJs1duMrfQEm7LgdaE98zbCem5LLvISP+qg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793208801; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=7+t7Qi/WPAFxXy7PWbJN4fjRYPB0/TUv+zpSfgkY6KQ=; b=k5DmTPr9KFRY301Mu+a5bG7honKxFxq6ZFruo/J5GZxQRUp8qc8kbeSQFY57Hapv9aI2 MZVyd4VwrkNHGnnCPtJC/ygmFwzsZgQnRAkTynwWmEwSo5XDioTFuUe+y0NW7Zyp1FxUX fKbj5xUYKKEB7afB+PW4i/rmdRFvjPaDjQghtQlAVY+7Y5lCsjnMIwTcptNBGKuUJEyqc Hr3CfDzhXL4b7v5rUOGYebPfNNv5l0thVfVEW5Zz3cxk72kg9x+iuRduWDuwAIuSA+qnE +VHtrd3I2Q59r5EyNCn/67uDyAqZk3Wy1eD5G0F+gmNN8jPq7phqFDJyUCiOeySuNNA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=yX+UuIXZ; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 90DAC606A31A; Wed, 28 Oct 2026 17:33:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=yX+UuIXZ Received: by smtp.kernel.org (Postfix) with ESMTPSA id E26F51F01825; Wed, 28 Oct 2026 17:33:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793208801; bh=7+t7Qi/WPAFxXy7PWbJN4fjRYPB0/TUv+zpSfgkY6KQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=yX+UuIXZf3MFa4f5sfD11nya9dYdA+ZoAZaszLh6mQAxME++wakEeVOW8DV8E67Uo USXtu3ZtNJll36hz0OwypKTvjbQ8vUGMynXOUwDAIlVqnY1lPAs4i+A8cGnOWAv1TS vwRFZbqq5HJwanAqB6hgog5ceIV2GqhZxNoPgRe0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chris Mason , Jeff Layton , Chuck Lever , Sasha Levin Subject: [PATCH 5.10 248/516] SUNRPC: fix gssx_dec_option_array error path bugs Date: Wed, 28 Oct 2026 17:56:40 +0100 Message-ID: <20261028170009.371972172@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170003.522232767@linuxfoundation.org> References: <20261028170003.522232767@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chris Mason [ Upstream commit 5e9a94539b1ec17a89177d952badfd0d844d694a ] Four coupled defects in the gssx XDR option-array decoder make the error paths unsafe: a NULL deref in the caller, a refcount leak on the decoded group_info, and a latent use-after-free that the leak fix would otherwise expose. gssx_dec_option_array() sets oa->count = 1 before allocating oa->data. If that allocation fails, -ENOMEM is returned with oa->count == 1 and oa->data == NULL. All other error paths jump to free_oa: which frees oa->data and NULLs it but also leaves oa->count == 1. The caller trusts the count: gssp_accept_sec_context_upcall() gssx_dec_accept_sec_context() gssx_dec_option_array() /* fails, count=1 data=NULL */ data = res.options.data[0].value /* NULL deref */ Independently, free_creds: releases the partially decoded svc_cred with a bare kfree(creds). gssx_dec_linux_creds() installs a groups_alloc() result into creds->cr_group_info; that object is kvmalloc-backed and refcounted, and only put_group_info() reaches kvfree(). A plain kfree(creds) drops the wrapper and leaks the group_info allocation. The natural fix for the leak is to call free_svc_cred(creds) before kfree(creds), but free_svc_cred() invokes put_group_info() on creds->cr_group_info unconditionally when non-NULL. The existing out_free_groups: path in gssx_dec_linux_creds() already called groups_free() on that pointer without clearing it, so once free_svc_cred() is wired in, the subsequent put_group_info() would touch freed memory. Fix all four together: - Move the oa->count = 1 assignment below the oa->data allocation so it is never set when oa->data is NULL. - Reset oa->count to 0 at free_oa: so count and data stay coherent and the caller sees an empty option array. - Call free_svc_cred(creds) before kfree(creds) at free_creds: so the refcounted cr_group_info is released. free_svc_cred() either NULL-guards each field explicitly (cr_group_info has an if() check) or delegates to a helper that is NULL-safe itself (kfree for the string fields, gss_mech_put() which guards with if(gm) at gss_mech_switch.c:342), so it is safe to call on a partially decoded svc_cred where only cr_uid/cr_gid/cr_group_info have been written and everything else is zero from kzalloc. - In gssx_dec_linux_creds()'s out_free_groups: path, release cr_group_info with put_group_info() rather than groups_free() so the teardown matches free_svc_cred()'s refcount-aware path, and clear the pointer so a later free_svc_cred() on the same creds does not release it a second time. Fixes: 3cfcfc102a5e ("SUNRPC: fix some memleaks in gssx_dec_option_array") Cc: stable@vger.kernel.org Assisted-by: kres (claude-opus-4-7) Signed-off-by: Chris Mason Reviewed-by: Jeff Layton Link: https://patch.msgid.link/20260528-tier2-v1-2-d026a1415e0b@oracle.com Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- net/sunrpc/auth_gss/gss_rpc_xdr.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c index c9268a17ea4ad..1f0bbc3a21c09 100644 --- a/net/sunrpc/auth_gss/gss_rpc_xdr.c +++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c @@ -222,7 +222,8 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr, return 0; out_free_groups: - groups_free(creds->cr_group_info); + put_group_info(creds->cr_group_info); + creds->cr_group_info = NULL; return err; } @@ -242,12 +243,12 @@ static int gssx_dec_option_array(struct xdr_stream *xdr, return 0; /* we recognize only 1 currently: CREDS_VALUE */ - oa->count = 1; - oa->data = kmalloc(sizeof(struct gssx_option), GFP_KERNEL); if (!oa->data) return -ENOMEM; + oa->count = 1; + creds = kzalloc(sizeof(struct svc_cred), GFP_KERNEL); if (!creds) { err = -ENOMEM; @@ -294,8 +295,10 @@ static int gssx_dec_option_array(struct xdr_stream *xdr, return 0; free_creds: + free_svc_cred(creds); kfree(creds); free_oa: + oa->count = 0; kfree(oa->data); oa->data = NULL; return err; -- 2.53.0