On 11/27/19 7:40 AM, jouni.hogander@xxxxxxxxxx wrote:
> From: Jouni Hogander <jouni.hogander@xxxxxxxxxx>
>
> 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@xxxxxxxxxxxxxx>
> Cc: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> Cc: David Miller <davem@xxxxxxxxxxxxx>
> Cc: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
> Cc: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>
> Signed-off-by: Jouni Hogander <jouni.hogander@xxxxxxxxxx>
> ---
Added to linux-can.
tnx,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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