From: Jan Höppner Date: Mon, 27 Jul 2026 14:28:39 +0000 (+0200) Subject: s390/dasd: Fix potential NULL pointer dereference X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9973026f572db6b67570cadc30942f3014e41079;p=thirdparty%2Flinux.git s390/dasd: Fix potential NULL pointer dereference dasd_release_space() checks the implementation of the is_ese() discipline function before calling it to determine if a given device is an ESE DASD. The current usage of the logical AND operator will lead to a NULL pointer dereference as the function is called even if the function pointer is NULL. Fix this by using the logical OR operator. Fixes: 91dc4a197569 ("s390/dasd: Add new ioctl to release space") Cc: stable@vger.kernel.org # v5.3+ Reported-by: Vasily Gorbik Acked-by: Eduard Shishkin Reviewed-by: Stefan Haberland Signed-off-by: Jan Höppner Signed-off-by: Stefan Haberland Link: https://patch.msgid.link/20260727142840.567286-3-sth@linux.ibm.com Signed-off-by: Jens Axboe --- diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c index c85ee42732a3..e5b8b413f5ab 100644 --- a/drivers/s390/block/dasd_ioctl.c +++ b/drivers/s390/block/dasd_ioctl.c @@ -324,7 +324,7 @@ out_err: static int dasd_release_space(struct dasd_device *device, struct format_data_t *rdata) { - if (!device->discipline->is_ese && !device->discipline->is_ese(device)) + if (!device->discipline->is_ese || !device->discipline->is_ese(device)) return -ENOTSUPP; if (!device->discipline->release_space) return -ENOTSUPP;