diff options
| author | Gui-Dong Han <hanguidong02@gmail.com> | 2026-01-14 00:28:43 +0800 |
|---|---|---|
| committer | Danilo Krummrich <dakr@kernel.org> | 2026-01-16 12:40:58 +0100 |
| commit | dc23806a7c47ec5f1293aba407fb69519f976ee0 (patch) | |
| tree | 71edf6fa646dc2cc50a105a1da96598e12b622c4 /drivers/base | |
| parent | a995fe1a3aa78b7d06cc1cc7b6b8436c5e93b07f (diff) | |
driver core: enforce device_lock for driver_match_device()
Currently, driver_match_device() is called from three sites. One site
(__device_attach_driver) holds device_lock(dev), but the other two
(bind_store and __driver_attach) do not. This inconsistency means that
bus match() callbacks are not guaranteed to be called with the lock
held.
Fix this by introducing driver_match_device_locked(), which guarantees
holding the device lock using a scoped guard. Replace the unlocked calls
in bind_store() and __driver_attach() with this new helper. Also add a
lock assertion to driver_match_device() to enforce this guarantee.
This consistency also fixes a known race condition. The driver_override
implementation relies on the device_lock, so the missing lock led to the
use-after-free (UAF) reported in Bugzilla for buses using this field.
Stress testing the two newly locked paths for 24 hours with
CONFIG_PROVE_LOCKING and CONFIG_LOCKDEP enabled showed no UAF recurrence
and no lockdep warnings.
Cc: stable@vger.kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789
Suggested-by: Qiu-ji Chen <chenqiuji666@gmail.com>
Signed-off-by: Gui-Dong Han <hanguidong02@gmail.com>
Fixes: 49b420a13ff9 ("driver core: check bus->match without holding device lock")
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Link: https://patch.msgid.link/20260113162843.12712-1-hanguidong02@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/base.h | 9 | ||||
| -rw-r--r-- | drivers/base/bus.c | 2 | ||||
| -rw-r--r-- | drivers/base/dd.c | 2 |
3 files changed, 11 insertions, 2 deletions
diff --git a/drivers/base/base.h b/drivers/base/base.h index 430cbefbc97f..677320881af1 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -182,9 +182,18 @@ void device_set_deferred_probe_reason(const struct device *dev, struct va_format static inline int driver_match_device(const struct device_driver *drv, struct device *dev) { + device_lock_assert(dev); + return drv->bus->match ? drv->bus->match(dev, drv) : 1; } +static inline int driver_match_device_locked(const struct device_driver *drv, + struct device *dev) +{ + guard(device)(dev); + return driver_match_device(drv, dev); +} + static inline void dev_sync_state(struct device *dev) { if (dev->bus->sync_state) diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 9eb7771706f0..331d750465e2 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -263,7 +263,7 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf, int err = -ENODEV; dev = bus_find_device_by_name(bus, NULL, buf); - if (dev && driver_match_device(drv, dev)) { + if (dev && driver_match_device_locked(drv, dev)) { err = device_driver_attach(drv, dev); if (!err) { /* success */ diff --git a/drivers/base/dd.c b/drivers/base/dd.c index bea8da5f8a3a..ed3a07624816 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -1180,7 +1180,7 @@ static int __driver_attach(struct device *dev, void *data) * is an error. */ - ret = driver_match_device(drv, dev); + ret = driver_match_device_locked(drv, dev); if (ret == 0) { /* no match */ return 0; |