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| author | Jouni Hogander <jouni.hogander@unikie.com> | 2019-11-27 09:40:26 +0300 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2019-12-03 13:15:08 +0300 |
| commit | 9ebd796e24008f33f06ebea5a5e6aceb68b51794 (patch) | |
| tree | 52764bbf5b3da2e2e838e713db37d59f9a31dcdc | |
| parent | 8c2a58568d6d952f7c7f1dac125b33dc8414627b (diff) | |
| download | linux-9ebd796e24008f33f06ebea5a5e6aceb68b51794.tar.xz | |
can: slcan: Fix use-after-free Read in slcan_open
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
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
| -rw-r--r-- | drivers/net/can/slcan.c | 1 |
1 files changed, 1 insertions, 0 deletions
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 @@ err_free_chan: sl->tty = NULL; tty->disc_data = NULL; clear_bit(SLF_INUSE, &sl->flags); + slc_free_netdev(sl->dev); free_netdev(sl->dev); err_exit: |