diff options
| author | Adrian Ambrozewicz <aambrozewicz@nvidia.com> | 2026-10-22 11:33:44 +0300 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com> | 2026-10-23 09:48:36 +0200 |
| commit | dae739137441667d67fbfcc4d303a0ecc6618662 (patch) | |
| tree | 9146df5f4646e593e92a19b84c64f267b59df436 | |
| parent | 15665047024e30f9c2227563d03034061c99ac2c (diff) | |
gpiolib: don't report -ENOMEM for a requested line without a label
gpiod_request_commit() sets GPIOD_FLAG_REQUESTED, calls ->request() and
only then sets the label. A line in between has no label, so
gpiochip_dup_line_label() passes NULL to kstrdup() and returns
ERR_PTR(-ENOMEM), which for_each_hwgpio() then passes to kfree():
BUG: unable to handle page fault for address: ffcc73074355ffc8
Call Trace:
gpio_sim_dbg_show
gpiolib_seq_show
seq_read_iter
Return NULL for such a line, as for an unrequested one.
Reproduced with gpio-sim: reading /sys/kernel/debug/gpio in a loop while
lines are requested and released oopses within seconds; with this
change, 100000 cycles pass.
Fixes: 35b545332b80 ("gpio: remove gpio_lock")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20261020-gpiolib-chip-removal-v3-0-aambrozewicz@nvidia.com?part=2
Assisted-by: LLM
Signed-off-by: Adrian Ambrozewicz <aambrozewicz@nvidia.com>
Link: https://patch.msgid.link/20261022083343.3905973-3-aambrozewicz@nvidia.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
| -rw-r--r-- | drivers/gpio/gpiolib.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 9decee5a95c7..90731a547ed6 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2721,6 +2721,7 @@ void gpiod_free(struct gpio_desc *desc) char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset) { struct gpio_desc *desc; + const char *name; char *label; desc = gpiochip_get_desc(gc, offset); @@ -2732,7 +2733,11 @@ char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset) guard(srcu)(&desc->gdev->desc_srcu); - label = kstrdup(gpiod_get_label(desc), GFP_KERNEL); + name = gpiod_get_label(desc); + if (!name) + return NULL; + + label = kstrdup(name, GFP_KERNEL); if (!label) return ERR_PTR(-ENOMEM); |