From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 17:05:56 -0700 Subject: bpf: mark a NULL kfunc argument precise check_kfunc_arg() allows bpf_register_is_null() for nullable arguments w/o marking the underlying scalar register precise. Hence a checkpoint created on such a path would prune against arbitrary scalar value. Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)") Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/tty/tty_mutex.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 drivers/tty/tty_mutex.c (limited to 'drivers/tty/tty_mutex.c') diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c new file mode 100644 index 000000000..784e46a0a --- /dev/null +++ b/drivers/tty/tty_mutex.c @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include "tty.h" + +/* Legacy tty mutex glue */ + +/* + * Getting the big tty mutex. + */ + +void tty_lock(struct tty_struct *tty) +{ + tty_kref_get(tty); + mutex_lock(&tty->legacy_mutex); +} +EXPORT_SYMBOL(tty_lock); + +int tty_lock_interruptible(struct tty_struct *tty) +{ + int ret; + + tty_kref_get(tty); + ret = mutex_lock_interruptible(&tty->legacy_mutex); + if (ret) + tty_kref_put(tty); + return ret; +} + +void tty_unlock(struct tty_struct *tty) +{ + mutex_unlock(&tty->legacy_mutex); + tty_kref_put(tty); +} +EXPORT_SYMBOL(tty_unlock); + +void tty_lock_slave(struct tty_struct *tty) +{ + if (tty && tty != tty->link) + tty_lock(tty); +} + +void tty_unlock_slave(struct tty_struct *tty) +{ + if (tty && tty != tty->link) + tty_unlock(tty); +} + +void tty_set_lock_subclass(struct tty_struct *tty) +{ + lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE); +} -- cgit v1.3.1