* [PATCH] kernel/dma: Fix panic caused by passing cma to command line
@ 2018-09-17 3:24 ` zhe.he
2018-09-18 9:28 ` Marek Szyprowski
0 siblings, 1 reply; 3+ messages in thread
From: zhe.he @ 2018-09-17 3:24 UTC (permalink / raw)
To: hch, m.szyprowski, robin.murphy, iommu, linux-kernel; +Cc: zhe.he
From: He Zhe <zhe.he@windriver.com>
early_cma does not check input argument before passing it to
simple_strtoull. The argument would be a NULL pointer if "cma", without
its value, is set in command line and thus causes the following panic.
PANIC: early exception 0xe3 IP 10:ffffffffa3e9db8d error 0 cr2 0x0
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-yocto-standard+ #7
[ 0.000000] RIP: 0010:_parse_integer_fixup_radix+0xd/0x70
...
[ 0.000000] Call Trace:
[ 0.000000] simple_strtoull+0x29/0x70
[ 0.000000] memparse+0x26/0x90
[ 0.000000] early_cma+0x17/0x6a
[ 0.000000] do_early_param+0x57/0x8e
[ 0.000000] parse_args+0x208/0x320
[ 0.000000] ? rdinit_setup+0x30/0x30
[ 0.000000] parse_early_options+0x29/0x2d
[ 0.000000] ? rdinit_setup+0x30/0x30
[ 0.000000] parse_early_param+0x36/0x4d
[ 0.000000] setup_arch+0x336/0x99e
[ 0.000000] start_kernel+0x6f/0x4e6
[ 0.000000] x86_64_start_reservations+0x24/0x26
[ 0.000000] x86_64_start_kernel+0x6f/0x72
[ 0.000000] secondary_startup_64+0xa4/0xb0
This patch adds a check to prevent the panic.
Signed-off-by: He Zhe <zhe.he@windriver.com>
Cc: stable@vger.kernel.org
Cc: hch@lst.de
Cc: m.szyprowski@samsung.com
Cc: robin.murphy@arm.com
---
kernel/dma/contiguous.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index 286d823..b2a8790 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -49,7 +49,11 @@ static phys_addr_t limit_cmdline;
static int __init early_cma(char *p)
{
- pr_debug("%s(%s)\n", __func__, p);
+ if (!p) {
+ pr_err("Config string not provided\n");
+ return -EINVAL;
+ }
+
size_cmdline = memparse(p, &p);
if (*p != '@')
return 0;
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] kernel/dma: Fix panic caused by passing cma to command line
2018-09-17 3:24 ` [PATCH] kernel/dma: Fix panic caused by passing cma to command line zhe.he
@ 2018-09-18 9:28 ` Marek Szyprowski
2018-09-20 6:54 ` Christoph Hellwig
0 siblings, 1 reply; 3+ messages in thread
From: Marek Szyprowski @ 2018-09-18 9:28 UTC (permalink / raw)
To: zhe.he, hch, robin.murphy, iommu, linux-kernel
Hi
On 2018-09-17 05:24, zhe.he@windriver.com wrote:
> From: He Zhe <zhe.he@windriver.com>
>
> early_cma does not check input argument before passing it to
> simple_strtoull. The argument would be a NULL pointer if "cma", without
> its value, is set in command line and thus causes the following panic.
>
> PANIC: early exception 0xe3 IP 10:ffffffffa3e9db8d error 0 cr2 0x0
> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-yocto-standard+ #7
> [ 0.000000] RIP: 0010:_parse_integer_fixup_radix+0xd/0x70
> ...
> [ 0.000000] Call Trace:
> [ 0.000000] simple_strtoull+0x29/0x70
> [ 0.000000] memparse+0x26/0x90
> [ 0.000000] early_cma+0x17/0x6a
> [ 0.000000] do_early_param+0x57/0x8e
> [ 0.000000] parse_args+0x208/0x320
> [ 0.000000] ? rdinit_setup+0x30/0x30
> [ 0.000000] parse_early_options+0x29/0x2d
> [ 0.000000] ? rdinit_setup+0x30/0x30
> [ 0.000000] parse_early_param+0x36/0x4d
> [ 0.000000] setup_arch+0x336/0x99e
> [ 0.000000] start_kernel+0x6f/0x4e6
> [ 0.000000] x86_64_start_reservations+0x24/0x26
> [ 0.000000] x86_64_start_kernel+0x6f/0x72
> [ 0.000000] secondary_startup_64+0xa4/0xb0
>
> This patch adds a check to prevent the panic.
>
> Signed-off-by: He Zhe <zhe.he@windriver.com>
> Cc: stable@vger.kernel.org
> Cc: hch@lst.de
> Cc: m.szyprowski@samsung.com
> Cc: robin.murphy@arm.com
Thanks for the fix.
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
> kernel/dma/contiguous.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
> index 286d823..b2a8790 100644
> --- a/kernel/dma/contiguous.c
> +++ b/kernel/dma/contiguous.c
> @@ -49,7 +49,11 @@ static phys_addr_t limit_cmdline;
>
> static int __init early_cma(char *p)
> {
> - pr_debug("%s(%s)\n", __func__, p);
> + if (!p) {
> + pr_err("Config string not provided\n");
> + return -EINVAL;
> + }
> +
> size_cmdline = memparse(p, &p);
> if (*p != '@')
> return 0;
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] kernel/dma: Fix panic caused by passing cma to command line
2018-09-18 9:28 ` Marek Szyprowski
@ 2018-09-20 6:54 ` Christoph Hellwig
0 siblings, 0 replies; 3+ messages in thread
From: Christoph Hellwig @ 2018-09-20 6:54 UTC (permalink / raw)
To: Marek Szyprowski; +Cc: zhe.he, hch, robin.murphy, iommu, linux-kernel
On Tue, Sep 18, 2018 at 11:28:33AM +0200, Marek Szyprowski wrote:
> Hi
>
> On 2018-09-17 05:24, zhe.he@windriver.com wrote:
> > From: He Zhe <zhe.he@windriver.com>
> >
> > early_cma does not check input argument before passing it to
> > simple_strtoull. The argument would be a NULL pointer if "cma", without
> > its value, is set in command line and thus causes the following panic.
> >
> > PANIC: early exception 0xe3 IP 10:ffffffffa3e9db8d error 0 cr2 0x0
> > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-yocto-standard+ #7
> > [ 0.000000] RIP: 0010:_parse_integer_fixup_radix+0xd/0x70
> > ...
> > [ 0.000000] Call Trace:
> > [ 0.000000] simple_strtoull+0x29/0x70
> > [ 0.000000] memparse+0x26/0x90
> > [ 0.000000] early_cma+0x17/0x6a
> > [ 0.000000] do_early_param+0x57/0x8e
> > [ 0.000000] parse_args+0x208/0x320
> > [ 0.000000] ? rdinit_setup+0x30/0x30
> > [ 0.000000] parse_early_options+0x29/0x2d
> > [ 0.000000] ? rdinit_setup+0x30/0x30
> > [ 0.000000] parse_early_param+0x36/0x4d
> > [ 0.000000] setup_arch+0x336/0x99e
> > [ 0.000000] start_kernel+0x6f/0x4e6
> > [ 0.000000] x86_64_start_reservations+0x24/0x26
> > [ 0.000000] x86_64_start_kernel+0x6f/0x72
> > [ 0.000000] secondary_startup_64+0xa4/0xb0
> >
> > This patch adds a check to prevent the panic.
> >
> > Signed-off-by: He Zhe <zhe.he@windriver.com>
> > Cc: stable@vger.kernel.org
> > Cc: hch@lst.de
> > Cc: m.szyprowski@samsung.com
> > Cc: robin.murphy@arm.com
>
> Thanks for the fix.
>
> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Thanks, added to the dma-mapping tree.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2018-09-17 3:24 ` [PATCH] kernel/dma: Fix panic caused by passing cma to command line zhe.he
2018-09-18 9:28 ` Marek Szyprowski
2018-09-20 6:54 ` Christoph Hellwig
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