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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Xiaolong Huang <butterflyhuangxx@gmail.com>,
	Arnd Bergmann <arnd@arndb.de>, Jakub Kicinski <kuba@kernel.org>,
	Sasha Levin <sashal@kernel.org>,
	isdn@linux-pingi.de, davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 06/10] isdn: cpai: check ctr->cnr to avoid array index out of bound
Date: Wed, 20 Oct 2021 20:23:01 -0400	[thread overview]
Message-ID: <20211021002305.1129633-6-sashal@kernel.org> (raw)
In-Reply-To: <20211021002305.1129633-1-sashal@kernel.org>

From: Xiaolong Huang <butterflyhuangxx@gmail.com>

[ Upstream commit 1f3e2e97c003f80c4b087092b225c8787ff91e4d ]

The cmtp_add_connection() would add a cmtp session to a controller
and run a kernel thread to process cmtp.

	__module_get(THIS_MODULE);
	session->task = kthread_run(cmtp_session, session, "kcmtpd_ctr_%d",
								session->num);

During this process, the kernel thread would call detach_capi_ctr()
to detach a register controller. if the controller
was not attached yet, detach_capi_ctr() would
trigger an array-index-out-bounds bug.

[   46.866069][ T6479] UBSAN: array-index-out-of-bounds in
drivers/isdn/capi/kcapi.c:483:21
[   46.867196][ T6479] index -1 is out of range for type 'capi_ctr *[32]'
[   46.867982][ T6479] CPU: 1 PID: 6479 Comm: kcmtpd_ctr_0 Not tainted
5.15.0-rc2+ #8
[   46.869002][ T6479] Hardware name: QEMU Standard PC (i440FX + PIIX,
1996), BIOS 1.14.0-2 04/01/2014
[   46.870107][ T6479] Call Trace:
[   46.870473][ T6479]  dump_stack_lvl+0x57/0x7d
[   46.870974][ T6479]  ubsan_epilogue+0x5/0x40
[   46.871458][ T6479]  __ubsan_handle_out_of_bounds.cold+0x43/0x48
[   46.872135][ T6479]  detach_capi_ctr+0x64/0xc0
[   46.872639][ T6479]  cmtp_session+0x5c8/0x5d0
[   46.873131][ T6479]  ? __init_waitqueue_head+0x60/0x60
[   46.873712][ T6479]  ? cmtp_add_msgpart+0x120/0x120
[   46.874256][ T6479]  kthread+0x147/0x170
[   46.874709][ T6479]  ? set_kthread_struct+0x40/0x40
[   46.875248][ T6479]  ret_from_fork+0x1f/0x30
[   46.875773][ T6479]

Signed-off-by: Xiaolong Huang <butterflyhuangxx@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20211008065830.305057-1-butterflyhuangxx@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/isdn/capi/kcapi.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/isdn/capi/kcapi.c b/drivers/isdn/capi/kcapi.c
index 18de41a266eb..aa625b7ddcce 100644
--- a/drivers/isdn/capi/kcapi.c
+++ b/drivers/isdn/capi/kcapi.c
@@ -565,6 +565,11 @@ int detach_capi_ctr(struct capi_ctr *ctr)
 
 	ctr_down(ctr, CAPI_CTR_DETACHED);
 
+	if (ctr->cnr < 1 || ctr->cnr - 1 >= CAPI_MAXCONTR) {
+		err = -EINVAL;
+		goto unlock_out;
+	}
+
 	if (capi_controller[ctr->cnr - 1] != ctr) {
 		err = -EINVAL;
 		goto unlock_out;
-- 
2.33.0


  parent reply	other threads:[~2021-10-21  0:24 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-21  0:22 [PATCH AUTOSEL 4.19 01/10] gcc-plugins/structleak: add makefile var for disabling structleak Sasha Levin
2021-10-21  0:22 ` [PATCH AUTOSEL 4.19 02/10] btrfs: deal with errors when checking if a dir entry exists during log replay Sasha Levin
2021-10-21  0:22 ` [PATCH AUTOSEL 4.19 03/10] net: stmmac: add support for dwmac 3.40a Sasha Levin
2021-10-21  0:22 ` [PATCH AUTOSEL 4.19 04/10] ARM: dts: spear3xx: Fix gmac node Sasha Levin
2021-10-21  0:23 ` [PATCH AUTOSEL 4.19 05/10] nfc: nci: fix the UAF of rf_conn_info object Sasha Levin
2021-10-21  0:23 ` Sasha Levin [this message]
2021-10-21  0:23 ` [PATCH AUTOSEL 4.19 07/10] isdn: mISDN: Fix sleeping function called from invalid context Sasha Levin
2021-10-21  0:23 ` [PATCH AUTOSEL 4.19 08/10] platform/x86: intel_scu_ipc: Update timeout value in comment Sasha Levin
2021-10-21  0:23 ` [PATCH AUTOSEL 4.19 09/10] ALSA: hda: avoid write to STATESTS if controller is in reset Sasha Levin
2021-10-21  0:23 ` [PATCH AUTOSEL 4.19 10/10] Input: xpad - add support for another USB ID of Nacon GC-100 Sasha Levin

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