From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8F664218AC4 for ; Wed, 31 Dec 2025 14:43:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767192185; cv=none; b=ARtJYQ1kuM/G04v5TDh1HfvOX3wxaRV22GrTctIrjwVxio0YNMH1ZH4DyoYnaDFeNab9iHD11hewjEDuWHVbFwPAX5A/BPC37uggNFae1Z75S306ax+dwUSvLpZuXU8aAAiIMT+rfQ11LOuygR1p9pS8xBMKYz8P1aTJzRpMXas= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767192185; c=relaxed/simple; bh=Wf4YHd+dxhB2if65y4eFcIKp7ok1VMy+QPjGD0PNhjg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MHCOzxbseqhzRRHPmkSHSzqPgfLl0AhCYoaTU7mW5pNp94UkehEh3GxwvVY8KsP1f7Vrpmzsnr7npe/nLQ5vLWUtkxhXSmtiUs0EkKBeecgQitDmKKtDaID/U2Ibaww/inEg95AMv8ifJAKw28WoHzKpxJczGKgHFeeR+olWSNI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NoZyYCNB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NoZyYCNB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E5D4C113D0; Wed, 31 Dec 2025 14:43:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767192185; bh=Wf4YHd+dxhB2if65y4eFcIKp7ok1VMy+QPjGD0PNhjg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NoZyYCNBKJKIYz/wSgtRSpMvWW1bSjijuscMY7FFzOLYjmteTQ8vnfdHNGxJGsdrb f/Df/zhUFRYRDX8lpm+K7Vfk+MpJC//Jt0l4K4ny9trs2nsbntOAhFO4u1TpKpdpPd ljlsS4kiDSu9RhvujrjSWf1DGhP74UR3cjomlhJYGPmVNagwrn268xD14F+z5aUOMG Fa08J4t0ABJQetycpbyG/gfaGhB6rrMHYBZtE+B0w9IqUE+EvDzcJH/0W9FghLLuDb nDlJgC3he3Yakr2uVVGbCquw9w7ErO6zmfayklIq/gY6dgX3CfH5bguZCJz/u58AS9 1HCe6E7hjpvHA== From: Sasha Levin To: stable@vger.kernel.org Cc: Joshua Rogers , Chuck Lever , Sasha Levin Subject: [PATCH 5.10.y] SUNRPC: svcauth_gss: avoid NULL deref on zero length gss_token in gss_read_proxy_verf Date: Wed, 31 Dec 2025 09:43:03 -0500 Message-ID: <20251231144303.3088891-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2025122941-pupil-strongly-abe3@gregkh> References: <2025122941-pupil-strongly-abe3@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Joshua Rogers [ Upstream commit d4b69a6186b215d2dc1ebcab965ed88e8d41768d ] A zero length gss_token results in pages == 0 and in_token->pages[0] is NULL. The code unconditionally evaluates page_address(in_token->pages[0]) for the initial memcpy, which can dereference NULL even when the copy length is 0. Guard the first memcpy so it only runs when length > 0. Fixes: 5866efa8cbfb ("SUNRPC: Fix svcauth_gss_proxy_init()") Cc: stable@vger.kernel.org Signed-off-by: Joshua Rogers Signed-off-by: Chuck Lever [ adapted xdr buffer pointer API to older argv iov_base/iov_len API ] Signed-off-by: Sasha Levin --- net/sunrpc/auth_gss/svcauth_gss.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index 329eac782cc5..fe85762dbd96 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -1177,7 +1177,8 @@ static int gss_read_proxy_verf(struct svc_rqst *rqstp, } length = min_t(unsigned int, inlen, argv->iov_len); - memcpy(page_address(in_token->pages[0]), argv->iov_base, length); + if (length) + memcpy(page_address(in_token->pages[0]), argv->iov_base, length); inlen -= length; to_offs = length; -- 2.51.0