[PATCH] phy: ti: Fix "BUG: KASAN: global-out-of-bounds in _get_maxdiv" issue

From: Kishon Vijay Abraham I
Date: Mon Jan 17 2022 - 06:01:25 EST


_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@xxxxxxxxxxxxxxx # v5.10+
Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
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