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authorEric Biggers <ebiggers@google.com>2020-02-24 10:20:43 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-03-18 13:15:13 +0100
commit17329563a97df3ba474eca5037c1336e46e14ff8 (patch)
treeb03f9e40dd29995f42a4f24bdcb7ff9aced554f4 /drivers/tty
parented069827ca70af057caf21c395f76c2c0b82d429 (diff)
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 'drivers/tty')
-rw-r--r--drivers/tty/tty_io.c4
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;