From: Julia Lawall Date: Wed, 23 Mar 2011 23:42:56 +0000 (-0700) Subject: drivers/tty/bfin_jtag_comm.c: avoid calling put_tty_driver on NULL X-Git-Tag: v2.6.39-rc1~132 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=d9d691f584bd012d235c35279c043a2ccd23d7d7;p=~shefty%2Frdma-dev.git drivers/tty/bfin_jtag_comm.c: avoid calling put_tty_driver on NULL put_tty_driver calls tty_driver_kref_put on its argument, and then tty_driver_kref_put calls kref_put on the address of a field of this argument. kref_put checks for NULL, but in this case the field is likely to have some offset and so the result of taking its address will not be NULL. Labels are added to be able to skip over the call to put_tty_driver when the argument will be NULL. The semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @@ expression *x; @@ *if (x == NULL) { ... * put_tty_driver(x); ... return ...; } // Signed-off-by: Julia Lawall Cc: Torben Hohn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/tty/bfin_jtag_comm.c b/drivers/tty/bfin_jtag_comm.c index 16402445f2b..03c285bb2f1 100644 --- a/drivers/tty/bfin_jtag_comm.c +++ b/drivers/tty/bfin_jtag_comm.c @@ -251,11 +251,11 @@ static int __init bfin_jc_init(void) bfin_jc_write_buf.head = bfin_jc_write_buf.tail = 0; bfin_jc_write_buf.buf = kmalloc(CIRC_SIZE, GFP_KERNEL); if (!bfin_jc_write_buf.buf) - goto err; + goto err_buf; bfin_jc_driver = alloc_tty_driver(1); if (!bfin_jc_driver) - goto err; + goto err_driver; bfin_jc_driver->owner = THIS_MODULE; bfin_jc_driver->driver_name = DRV_NAME; @@ -275,7 +275,9 @@ static int __init bfin_jc_init(void) err: put_tty_driver(bfin_jc_driver); + err_driver: kfree(bfin_jc_write_buf.buf); + err_buf: kthread_stop(bfin_jc_kthread); return ret; }