From: Marek Szyprowski <m.szyprowski@samsung.com>
To: linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: Marek Szyprowski <m.szyprowski@samsung.com>,
Russell King <linux@armlinux.org.uk>,
Michael Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@kernel.org>
Subject: [PATCH] clkdev: fix potential NULL pointer dereference
Date: Tue, 7 May 2024 08:44:34 +0200 [thread overview]
Message-ID: <20240507064434.3213933-1-m.szyprowski@samsung.com> (raw)
In-Reply-To: CGME20240507064445eucas1p1bfc17da4f824ef46567774634482f12f@eucas1p1.samsung.com
dev_fmt argument is optional, so avoid dereferencing it unconditionally.
Fixes: 4d11c62ca8d7 ("clkdev: report over-sized strings when creating clkdev entries")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
This fixes the following kernel panic observed on Samsung Exynos542x
SoCs family:
8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read
[00000000] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.8.0-00001-g4d11c62ca8d7 #14975
Hardware name: Samsung Exynos (Flattened Device Tree)
PC is at vsnprintf+0x4c/0x3c8
LR is at init_stack+0x1dd6/0x2000
pc : [<c0c09d3c>] lr : [<c1301dd6>] psr: 800000d3
...
Flags: Nzcv IRQs off FIQs off Mode SVC_32 ISA ARM Segment none
Control: 10c5387d Table: 4000406a DAC: 00000051
...
Process swapper/0 (pid: 0, stack limit = 0x(ptrval))
Stack: (0xc1301c70 to 0xc1302000)
...
vsnprintf from va_format.constprop.0+0x70/0x160
va_format.constprop.0 from pointer+0x454/0x670
pointer from vsnprintf+0x228/0x3c8
vsnprintf from vprintk_store+0x100/0x428
vprintk_store from vprintk_emit+0x6c/0x328
vprintk_emit from vprintk_default+0x24/0x2c
vprintk_default from _printk+0x28/0x4c
_printk from vclkdev_alloc+0xf0/0x110
vclkdev_alloc from clkdev_hw_create+0x28/0x88
clkdev_hw_create from clk_hw_register_clkdev+0x38/0x3c
clk_hw_register_clkdev from samsung_clk_register_fixed_rate+0xa4/0xd4
samsung_clk_register_fixed_rate from exynos5x_clk_init+0xf0/0x2b0
exynos5x_clk_init from of_clk_init+0x15c/0x228
of_clk_init from time_init+0x24/0x30
time_init from start_kernel+0x4b8/0x620
start_kernel from 0x0
Code: e09e9001 e1a05002 e28da01c 2a000086 (e5d50000)
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Attempted to kill the idle task!
---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---
Best regards
Marek Szyprowski, PhD
Samsung R&D Institute Poland
---
drivers/clk/clkdev.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index ddacab7863d0..d2801ae70e34 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -194,10 +194,12 @@ vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
return &cla->cl;
fail:
- fmt.fmt = dev_fmt;
- fmt.va = &ap_copy;
- pr_err("%pV:%s: %s ID is greater than %zu\n",
- &fmt, con_id, failure, max_size);
+ if (dev_fmt) {
+ fmt.fmt = dev_fmt;
+ fmt.va = &ap_copy;
+ pr_err("%pV:%s: %s ID is greater than %zu\n",
+ &fmt, con_id, failure, max_size);
+ }
va_end(ap_copy);
kfree(cla);
return NULL;
--
2.34.1
next parent reply other threads:[~2024-05-07 6:44 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20240507064445eucas1p1bfc17da4f824ef46567774634482f12f@eucas1p1.samsung.com>
2024-05-07 6:44 ` Marek Szyprowski [this message]
2024-05-07 9:34 ` [PATCH] clkdev: fix potential NULL pointer dereference Russell King (Oracle)
2024-05-07 16:42 ` André Draszik
2024-05-07 17:58 ` Russell King (Oracle)
2024-05-08 20:52 ` Sam Protsenko
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