| Message ID | 20191203104703.14620-4-mkl@pengutronix.de |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | pull-request: can 2019-12-03 | expand |
On 03/12/2019 11.47, Marc Kleine-Budde wrote: > From: Jouni Hogander <jouni.hogander@unikie.com> > > Slcan_open doesn't clean-up device which registration failed from the > slcan_devs device list. On next open this list is iterated and freed > device is accessed. Fix this by calling slc_free_netdev in error path. > > Driver/net/can/slcan.c is derived from slip.c. Use-after-free error was > identified in slip_open by syzboz. Same bug is in slcan.c. Here is the > trace from the Syzbot slip report: > > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x197/0x210 lib/dump_stack.c:118 > print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 > __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 > kasan_report+0x12/0x20 mm/kasan/common.c:634 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 > sl_sync drivers/net/slip/slip.c:725 [inline] > slip_open+0xecd/0x11b7 drivers/net/slip/slip.c:801 > tty_ldisc_open.isra.0+0xa3/0x110 drivers/tty/tty_ldisc.c:469 > tty_set_ldisc+0x30e/0x6b0 drivers/tty/tty_ldisc.c:596 > tiocsetd drivers/tty/tty_io.c:2334 [inline] > tty_ioctl+0xe8d/0x14f0 drivers/tty/tty_io.c:2594 > vfs_ioctl fs/ioctl.c:46 [inline] > file_ioctl fs/ioctl.c:509 [inline] > do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696 > ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 > __do_sys_ioctl fs/ioctl.c:720 [inline] > __se_sys_ioctl fs/ioctl.c:718 [inline] > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 > do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Fixes: ed50e1600b44 ("slcan: Fix memory leak in error path") > Cc: Wolfgang Grandegger <wg@grandegger.com> > Cc: Marc Kleine-Budde <mkl@pengutronix.de> > Cc: David Miller <davem@davemloft.net> > Cc: Oliver Hartkopp <socketcan@hartkopp.net> > Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> > Signed-off-by: Jouni Hogander <jouni.hogander@unikie.com> > Cc: linux-stable <stable@vger.kernel.org> # >= v5.4 I think this problem existed from the initial commit in 2010 and is not restricted to >= v5.4 Together with commit commit ed50e1600b4483c049 ("slcan: Fix memory leak in error path") from Jouni Hogander. Regards, Oliver > Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> > Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> > --- > drivers/net/can/slcan.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c > index 0a9f42e5fedf..2e57122f02fb 100644 > --- a/drivers/net/can/slcan.c > +++ b/drivers/net/can/slcan.c > @@ -617,6 +617,7 @@ static int slcan_open(struct tty_struct *tty) > sl->tty = NULL; > tty->disc_data = NULL; > clear_bit(SLF_INUSE, &sl->flags); > + slc_free_netdev(sl->dev); > free_netdev(sl->dev); > > err_exit: >
On 12/3/19 12:21 PM, Oliver Hartkopp wrote: > > > On 03/12/2019 11.47, Marc Kleine-Budde wrote: >> From: Jouni Hogander <jouni.hogander@unikie.com> >> >> Slcan_open doesn't clean-up device which registration failed from the >> slcan_devs device list. On next open this list is iterated and freed >> device is accessed. Fix this by calling slc_free_netdev in error path. >> >> Driver/net/can/slcan.c is derived from slip.c. Use-after-free error was >> identified in slip_open by syzboz. Same bug is in slcan.c. Here is the >> trace from the Syzbot slip report: >> >> __dump_stack lib/dump_stack.c:77 [inline] >> dump_stack+0x197/0x210 lib/dump_stack.c:118 >> print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 >> __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 >> kasan_report+0x12/0x20 mm/kasan/common.c:634 >> __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 >> sl_sync drivers/net/slip/slip.c:725 [inline] >> slip_open+0xecd/0x11b7 drivers/net/slip/slip.c:801 >> tty_ldisc_open.isra.0+0xa3/0x110 drivers/tty/tty_ldisc.c:469 >> tty_set_ldisc+0x30e/0x6b0 drivers/tty/tty_ldisc.c:596 >> tiocsetd drivers/tty/tty_io.c:2334 [inline] >> tty_ioctl+0xe8d/0x14f0 drivers/tty/tty_io.c:2594 >> vfs_ioctl fs/ioctl.c:46 [inline] >> file_ioctl fs/ioctl.c:509 [inline] >> do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696 >> ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 >> __do_sys_ioctl fs/ioctl.c:720 [inline] >> __se_sys_ioctl fs/ioctl.c:718 [inline] >> __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 >> do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 >> entry_SYSCALL_64_after_hwframe+0x49/0xbe >> >> Fixes: ed50e1600b44 ("slcan: Fix memory leak in error path") >> Cc: Wolfgang Grandegger <wg@grandegger.com> >> Cc: Marc Kleine-Budde <mkl@pengutronix.de> >> Cc: David Miller <davem@davemloft.net> >> Cc: Oliver Hartkopp <socketcan@hartkopp.net> >> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> >> Signed-off-by: Jouni Hogander <jouni.hogander@unikie.com> >> Cc: linux-stable <stable@vger.kernel.org> # >= v5.4 > > I think this problem existed from the initial commit in 2010 and is not > restricted to >= v5.4 > > Together with commit commit ed50e1600b4483c049 ("slcan: Fix memory leak > in error path") from Jouni Hogander. Yes, both patches shoud be backported: ed50e1600b44 slcan: Fix memory leak in error path 9ebd796e2400 can: slcan: Fix use-after-free Read in slcan_open Marc
diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index 0a9f42e5fedf..2e57122f02fb 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -617,6 +617,7 @@ static int slcan_open(struct tty_struct *tty) sl->tty = NULL; tty->disc_data = NULL; clear_bit(SLF_INUSE, &sl->flags); + slc_free_netdev(sl->dev); free_netdev(sl->dev); err_exit: