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authorJouni Hogander <jouni.hogander@unikie.com>2019-11-25 15:23:43 +0300
committerDavid S. Miller <davem@davemloft.net>2019-11-25 22:02:52 +0300
commite58c1912418980f57ba2060017583067f5f71e52 (patch)
treed5e801095e709d00fa37917c03d1b2a2f7630c05 /drivers/net/slip
parent9bca3a0a923fc3f0fb9e41391be1d0f291e86858 (diff)
downloadlinux-e58c1912418980f57ba2060017583067f5f71e52.tar.xz
slip: Fix use-after-free Read in slip_open
Slip_open doesn't clean-up device which registration failed from the slip_devs device list. On next open after failure this list is iterated and freed device is accessed. Fix this by calling sl_free_netdev in error path. Here is the trace from the Syzbot: __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: 3b5a39979daf ("slip: Fix memory leak in slip_open error path") Reported-by: syzbot+4d5170758f3762109542@syzkaller.appspotmail.com 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> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/slip')
-rw-r--r--drivers/net/slip/slip.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/net/slip/slip.c b/drivers/net/slip/slip.c
index 4d479e3c817d..2a91c192659f 100644
--- a/drivers/net/slip/slip.c
+++ b/drivers/net/slip/slip.c
@@ -855,6 +855,7 @@ err_free_chan:
sl->tty = NULL;
tty->disc_data = NULL;
clear_bit(SLF_INUSE, &sl->flags);
+ sl_free_netdev(sl->dev);
free_netdev(sl->dev);
err_exit: