lkml.org 
[lkml]   [2019]   [May]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 1/2] hwtracing: stm: fix vfree() nonexistent vm_area
From
Date
sorry, send wrong version,  please ignore.

On 2019/5/20 17:13, Kefeng Wang wrote:
> If device_add() in stm_register_device() fails, stm_device_release()
> is called to free stm, free stm again on err_device path will trigger
> following warning,
>
> Trying to vfree() nonexistent vm area (0000000054b5e7bc)
> WARNING: CPU: 0 PID: 6004 at mm/vmalloc.c:1595 __vunmap+0x72/0x480 mm/vmalloc.c:1594
> Kernel panic - not syncing: panic_on_warn set ...
> CPU: 0 PID: 6004 Comm: syz-executor.0 Tainted: G C 5.1.0+ #28
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
> Call Trace:
> __vfree+0x2a/0x80 mm/vmalloc.c:1658
> _vfree+0x49/0x70 mm/vmalloc.c:1688
> stm_register_device+0x295/0x330 [stm_core]
> dummy_stm_init+0xfe/0x1e0 [dummy_stm]
> do_one_initcall+0xb9/0x3b5 init/main.c:914
> do_init_module+0xe0/0x330 kernel/module.c:3468
> load_module+0x38eb/0x4270 kernel/module.c:3819
> __do_sys_finit_module+0x162/0x190 kernel/module.c:3909
> do_syscall_64+0x72/0x2a0 arch/x86/entry/common.c:298
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> Only free stm once if device_add() fails to fix it.
>
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
> drivers/hwtracing/stm/core.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
> index e55b902560de..7b2ab7b2cc4d 100644
> --- a/drivers/hwtracing/stm/core.c
> +++ b/drivers/hwtracing/stm/core.c
> @@ -864,6 +864,7 @@ static void stm_device_release(struct device *dev)
> struct stm_device *stm = to_stm_device(dev);
>
> vfree(stm);
> + stm->data->stm = NULL;
> }
>
> int stm_register_device(struct device *parent, struct stm_data *stm_data,
> @@ -933,7 +934,8 @@ int stm_register_device(struct device *parent, struct stm_data *stm_data,
> /* matches device_initialize() above */
> put_device(&stm->dev);
> err_free:
> - vfree(stm);
> + if (stm->data->stm)
> + vfree(stm);
>
> return err;
> }

\
 
 \ /
  Last update: 2019-05-20 11:22    [W:0.032 / U:0.268 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site