Messages in this thread | | | Subject | Re: [PATCH 1/2] hwtracing: stm: fix vfree() nonexistent vm_area | From | Kefeng Wang <> | Date | Mon, 20 May 2019 17:19:49 +0800 |
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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; > }
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