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From:   Kishon Vijay Abraham I <kishon@ti.com>
To:     Kishon Vijay Abraham I <kishon@ti.com>,
        Vinod Koul <vkoul@kernel.org>
CC:     Swapnil Jakhade <sjakhade@cadence.com>,
        <linux-phy@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
        <stable@vger.kernel.org>
Subject: [PATCH] phy: ti: Fix "BUG: KASAN: global-out-of-bounds in _get_maxdiv" issue
Date:   Mon, 17 Jan 2022 16:31:08 +0530
Message-ID: <20220117110108.4117-1-kishon@ti.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

_get_table_maxdiv() tries to access "clk_div_table" array out of bound
defined in phy-j721e-wiz.c. Add a sentinel entry to prevent
the following global-out-of-bounds error reported by enabling KASAN.

[    9.552392] BUG: KASAN: global-out-of-bounds in _get_maxdiv+0xc0/0x148
[    9.558948] Read of size 4 at addr ffff8000095b25a4 by task kworker/u4:1/38
[    9.565926]
[    9.567441] CPU: 1 PID: 38 Comm: kworker/u4:1 Not tainted 5.16.0-116492-gdaadb3bd0e8d-dirty #360
[    9.576242] Hardware name: Texas Instruments J721e EVM (DT)
[    9.581832] Workqueue: events_unbound deferred_probe_work_func
[    9.587708] Call trace:
[    9.590174]  dump_backtrace+0x20c/0x218
[    9.594038]  show_stack+0x18/0x68
[    9.597375]  dump_stack_lvl+0x9c/0xd8
[    9.601062]  print_address_description.constprop.0+0x78/0x334
[    9.606830]  kasan_report+0x1f0/0x260
[    9.610517]  __asan_load4+0x9c/0xd8
[    9.614030]  _get_maxdiv+0xc0/0x148
[    9.617540]  divider_determine_rate+0x88/0x488
[    9.622005]  divider_round_rate_parent+0xc8/0x124
[    9.626729]  wiz_clk_div_round_rate+0x54/0x68
[    9.631113]  clk_core_determine_round_nolock+0x124/0x158
[    9.636448]  clk_core_round_rate_nolock+0x68/0x138
[    9.641260]  clk_core_set_rate_nolock+0x268/0x3a8
[    9.645987]  clk_set_rate+0x50/0xa8
[    9.649499]  cdns_sierra_phy_init+0x88/0x248
[    9.653794]  phy_init+0x98/0x108
[    9.657046]  cdns_pcie_enable_phy+0xa0/0x170
[    9.661340]  cdns_pcie_init_phy+0x250/0x2b0
[    9.665546]  j721e_pcie_probe+0x4b8/0x798
[    9.669579]  platform_probe+0x8c/0x108
[    9.673350]  really_probe+0x114/0x630
[    9.677037]  __driver_probe_device+0x18c/0x220
[    9.681505]  driver_probe_device+0xac/0x150
[    9.685712]  __device_attach_driver+0xec/0x170
[    9.690178]  bus_for_each_drv+0xf0/0x158
[    9.694124]  __device_attach+0x184/0x210
[    9.698070]  device_initial_probe+0x14/0x20
[    9.702277]  bus_probe_device+0xec/0x100
[    9.706223]  deferred_probe_work_func+0x124/0x180
[    9.710951]  process_one_work+0x4b0/0xbc0
[    9.714983]  worker_thread+0x74/0x5d0
[    9.718668]  kthread+0x214/0x230
[    9.721919]  ret_from_fork+0x10/0x20
[    9.725520]
[    9.727032] The buggy address belongs to the variable:
[    9.732183]  clk_div_table+0x24/0x440

Fixes: 091876cc35 ("phy: ti: j721e-wiz: Add support for WIZ module present in TI J721E SoC")
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/phy/ti/phy-j721e-wiz.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/phy/ti/phy-j721e-wiz.c b/drivers/phy/ti/phy-j721e-wiz.c
index b3384c31637a..da546c35d1d5 100644
--- a/drivers/phy/ti/phy-j721e-wiz.c
+++ b/drivers/phy/ti/phy-j721e-wiz.c
@@ -233,6 +233,7 @@ static const struct clk_div_table clk_div_table[] = {
 	{ .val = 1, .div = 2, },
 	{ .val = 2, .div = 4, },
 	{ .val = 3, .div = 8, },
+	{ /* sentinel */ },
 };
 
 static const struct wiz_clk_div_sel clk_div_sel[] = {
-- 
2.17.1