diff options
| author |   Eric Biggers <ebiggers@google.com> | 2020-02-24 10:20:43 -0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-18 13:15:13 +0100 |
| commit | 17329563a97df3ba474eca5037c1336e46e14ff8 (patch) | |
| tree | b03f9e40dd29995f42a4f24bdcb7ff9aced554f4 /drivers/tty/tty_io.c | |
| parent | tty: drop outdated comments about release_tty() locking (diff) | |
| download | linux-dev-17329563a97df3ba474eca5037c1336e46e14ff8.tar.xz linux-dev-17329563a97df3ba474eca5037c1336e46e14ff8.zip | |
tty: fix compat TIOCGSERIAL leaking uninitialized memory
Commit 77654350306a ("take compat TIOC[SG]SERIAL treatment into
tty_compat_ioctl()") changed the compat version of TIOCGSERIAL to start
copying a whole 'serial_struct32' to userspace rather than individual
fields, but failed to initialize all padding and fields -- namely the
hole after the 'iomem_reg_shift' field, and the 'reserved' field.
Fix this by initializing the struct to zero.
[v2: use sizeof, and convert the adjacent line for consistency.]
Reported-by: syzbot+8da9175e28eadcb203ce@syzkaller.appspotmail.com
Fixes: 77654350306a ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()")
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200224182044.234553-2-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to '')
| -rw-r--r-- | drivers/tty/tty_io.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 1fcf7ad83dfa..db4a13bc855e 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2730,7 +2730,9 @@ static int compat_tty_tiocgserial(struct tty_struct *tty, struct serial_struct32 v32; struct serial_struct v; int err; - memset(&v, 0, sizeof(struct serial_struct)); + + memset(&v, 0, sizeof(v)); + memset(&v32, 0, sizeof(v32)); if (!tty->ops->set_serial) return -ENOTTY; |