From: Mazin Al Haddad mazinalhaddad05@gmail.com
[ Upstream commit 94d90fb06b94a90c176270d38861bcba34ce377d ]
Syzbot reports a memory leak in "dvb_usb_adapter_init()". The leak is due to not accounting for and freeing current iteration's adapter->priv in case of an error. Currently if an error occurs, it will exit before incrementing "num_adapters_initalized", which is used as a reference counter to free all adap->priv in "dvb_usb_adapter_exit()". There are multiple error paths that can exit from before incrementing the counter. Including the error handling paths for "dvb_usb_adapter_stream_init()", "dvb_usb_adapter_dvb_init()" and "dvb_usb_adapter_frontend_init()" within "dvb_usb_adapter_init()".
This means that in case of an error in any of these functions the current iteration is not accounted for and the current iteration's adap->priv is not freed.
Fix this by freeing the current iteration's adap->priv in the "stream_init_err:" label in the error path. The rest of the (accounted for) adap->priv objects are freed in dvb_usb_adapter_exit() as expected using the num_adapters_initalized variable.
Syzbot report:
BUG: memory leak unreferenced object 0xffff8881172f1a00 (size 512): comm "kworker/0:2", pid 139, jiffies 4294994873 (age 10.960s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff844af012>] dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:75 [inline] [<ffffffff844af012>] dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:184 [inline] [<ffffffff844af012>] dvb_usb_device_init.cold+0x4e5/0x79e drivers/media/usb/dvb-usb/dvb-usb-init.c:308 [<ffffffff830db21d>] dib0700_probe+0x8d/0x1b0 drivers/media/usb/dvb-usb/dib0700_core.c:883 [<ffffffff82d3fdc7>] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396 [<ffffffff8274ab37>] call_driver_probe drivers/base/dd.c:542 [inline] [<ffffffff8274ab37>] really_probe.part.0+0xe7/0x310 drivers/base/dd.c:621 [<ffffffff8274ae6c>] really_probe drivers/base/dd.c:583 [inline] [<ffffffff8274ae6c>] __driver_probe_device+0x10c/0x1e0 drivers/base/dd.c:752 [<ffffffff8274af6a>] driver_probe_device+0x2a/0x120 drivers/base/dd.c:782 [<ffffffff8274b786>] __device_attach_driver+0xf6/0x140 drivers/base/dd.c:899 [<ffffffff82747c87>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:427 [<ffffffff8274b352>] __device_attach+0x122/0x260 drivers/base/dd.c:970 [<ffffffff827498f6>] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:487 [<ffffffff82745cdb>] device_add+0x5fb/0xdf0 drivers/base/core.c:3405 [<ffffffff82d3d202>] usb_set_configuration+0x8f2/0xb80 drivers/usb/core/message.c:2170 [<ffffffff82d4dbfc>] usb_generic_driver_probe+0x8c/0xc0 drivers/usb/core/generic.c:238 [<ffffffff82d3f49c>] usb_probe_device+0x5c/0x140 drivers/usb/core/driver.c:293 [<ffffffff8274ab37>] call_driver_probe drivers/base/dd.c:542 [inline] [<ffffffff8274ab37>] really_probe.part.0+0xe7/0x310 drivers/base/dd.c:621 [<ffffffff8274ae6c>] really_probe drivers/base/dd.c:583 [inline] [<ffffffff8274ae6c>] __driver_probe_device+0x10c/0x1e0 drivers/base/dd.c:752
Link: https://syzkaller.appspot.com/bug?extid=f66dd31987e6740657be Reported-and-tested-by: syzbot+f66dd31987e6740657be@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-media/20220824012152.539788-1-mazinalhaddad05@... Signed-off-by: Mazin Al Haddad mazinalhaddad05@gmail.com Signed-off-by: Mauro Carvalho Chehab mchehab@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/usb/dvb-usb/dvb-usb-init.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c index e7720ff11d3d..cb5bf119df9f 100644 --- a/drivers/media/usb/dvb-usb/dvb-usb-init.c +++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c @@ -81,7 +81,7 @@ static int dvb_usb_adapter_init(struct dvb_usb_device *d, short *adapter_nrs)
ret = dvb_usb_adapter_stream_init(adap); if (ret) - return ret; + goto stream_init_err;
ret = dvb_usb_adapter_dvb_init(adap, adapter_nrs); if (ret) @@ -114,6 +114,8 @@ static int dvb_usb_adapter_init(struct dvb_usb_device *d, short *adapter_nrs) dvb_usb_adapter_dvb_exit(adap); dvb_init_err: dvb_usb_adapter_stream_exit(adap); +stream_init_err: + kfree(adap->priv); return ret; }