diff options
| author | Matthias Schwarzott <zzam@gentoo.org> | 2017-08-02 12:46:00 -0400 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2017-08-27 06:33:47 -0400 |
| commit | e59eb4adf0d79fe7692c08c07445ec9efc8ddc1c (patch) | |
| tree | c770a4bdb12f205cc26bb61a1bf7ad88abe4ccf9 /drivers/media | |
| parent | 412b16d623cf4fd794713f314db5aad10c46ad87 (diff) | |
media: cx231xx: fix use-after-free when unregistering the i2c_client for the dvb demod
Calling i2c_unregister_device for a demod driver destroys the frontend object.
Later it is accessed by calling dvb_unregister_frontend and
dvb_frontend_detach.
In some cases this leads to a general protection fault with this
callstack:
dvb_unregister_frontend+0x25/0x50 [dvb_core]
dvb_fini+0xdb/0x160 [cx231xx_dvb]
cx231xx_unregister_extension+0x3d/0xb0 [cx231xx]
cx231xx_dvb_unregister+0x10/0x809 [cx231xx_dvb]
SyS_delete_module+0x18a/0x240
? exit_to_usermode_loop+0x7b/0x80
entry_SYSCALL_64_fastpath+0x17/0x98
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/usb/cx231xx/cx231xx-dvb.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/media/usb/cx231xx/cx231xx-dvb.c b/drivers/media/usb/cx231xx/cx231xx-dvb.c index ee3eeeb600f8..c18bb33e060e 100644 --- a/drivers/media/usb/cx231xx/cx231xx-dvb.c +++ b/drivers/media/usb/cx231xx/cx231xx-dvb.c @@ -585,6 +585,9 @@ static void unregister_dvb(struct cx231xx_dvb *dvb) dvb->demux.dmx.remove_frontend(&dvb->demux.dmx, &dvb->fe_hw); dvb_dmxdev_release(&dvb->dmxdev); dvb_dmx_release(&dvb->demux); + dvb_unregister_frontend(dvb->frontend); + dvb_frontend_detach(dvb->frontend); + dvb_unregister_adapter(&dvb->adapter); /* remove I2C tuner */ client = dvb->i2c_client_tuner; if (client) { @@ -597,9 +600,6 @@ static void unregister_dvb(struct cx231xx_dvb *dvb) module_put(client->dev.driver->owner); i2c_unregister_device(client); } - dvb_unregister_frontend(dvb->frontend); - dvb_frontend_detach(dvb->frontend); - dvb_unregister_adapter(&dvb->adapter); } static int dvb_init(struct cx231xx *dev) |