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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Petr Malat <oss@malat.biz>,
        Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH 5.4 20/85] sctp: Fix COMM_LOST/CANT_STR_ASSOC err reporting on big-endian platforms
Date:   Mon,  9 Nov 2020 13:55:17 +0100
Message-Id: <20201109125023.555225859@linuxfoundation.org>
In-Reply-To: <20201109125022.614792961@linuxfoundation.org>
References: <20201109125022.614792961@linuxfoundation.org>
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From: Petr Malat <oss@malat.biz>

[ Upstream commit b6df8c81412190fbd5eaa3cec7f642142d9c16cd ]

Commit 978aa0474115 ("sctp: fix some type cast warnings introduced since
very beginning")' broke err reading from sctp_arg, because it reads the
value as 32-bit integer, although the value is stored as 16-bit integer.
Later this value is passed to the userspace in 16-bit variable, thus the
user always gets 0 on big-endian platforms. Fix it by reading the __u16
field of sctp_arg union, as reading err field would produce a sparse
warning.

Fixes: 978aa0474115 ("sctp: fix some type cast warnings introduced since very beginning")
Signed-off-by: Petr Malat <oss@malat.biz>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Link: https://lore.kernel.org/r/20201030132633.7045-1-oss@malat.biz
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/sctp/sm_sideeffect.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/sctp/sm_sideeffect.c
+++ b/net/sctp/sm_sideeffect.c
@@ -1600,12 +1600,12 @@ static int sctp_cmd_interpreter(enum sct
 			break;
 
 		case SCTP_CMD_INIT_FAILED:
-			sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
+			sctp_cmd_init_failed(commands, asoc, cmd->obj.u16);
 			break;
 
 		case SCTP_CMD_ASSOC_FAILED:
 			sctp_cmd_assoc_failed(commands, asoc, event_type,
-					      subtype, chunk, cmd->obj.u32);
+					      subtype, chunk, cmd->obj.u16);
 			break;
 
 		case SCTP_CMD_INIT_COUNTER_INC: