linux/drivers/s390
Jan Höppner db46cd1e04 s390/dasd: protect device queue against concurrent access
In dasd_profile_start() the amount of requests on the device queue are
counted. The access to the device queue is unprotected against
concurrent access. With a lot of parallel I/O, especially with alias
devices enabled, the device queue can change while dasd_profile_start()
is accessing the queue. In the worst case this leads to a kernel panic
due to incorrect pointer accesses.

Fix this by taking the device lock before accessing the queue and
counting the requests. Additionally the check for a valid profile data
pointer can be done earlier to avoid unnecessary locking in a hot path.

Cc:  <stable@vger.kernel.org>
Fixes: 4fa52aa7a8 ("[S390] dasd: add enhanced DASD statistics interface")
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Link: https://lore.kernel.org/r/20231025132437.1223363-3-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-20 11:50:54 -07:00
..
block s390/dasd: protect device queue against concurrent access 2023-11-20 11:50:54 -07:00
char s390/sclp: replace deprecated strncpy with strtomem 2023-10-25 15:08:30 +02:00
cio s390 updates for the 6.7 merge window 2023-11-03 10:17:22 -10:00
crypto s390/ap: fix vanishing crypto cards in SE environment 2023-11-05 22:34:57 +01:00
net s390/qeth: Fix typo 'weed' in comment 2023-11-07 22:17:20 +00:00
scsi scsi: zfcp: Fix a double put in zfcp_port_enqueue() 2023-09-27 11:31:20 -04:00
virtio s390/airq: remove lsi_mask from airq_struct 2023-08-30 11:03:28 +02:00
Makefile