[PATCH 4.14 02/36] blkdev_report_zones_ioctl(): Use vmalloc() to allocate large buffers

From: Greg Kroah-Hartman
Date: Thu Jun 14 2018 - 10:09:56 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Bart Van Assche <bart.vanassche@xxxxxxx>

commit 327ea4adcfa37194739f1ec7c70568944d292281 upstream.

Avoid that complaints similar to the following appear in the kernel log
if the number of zones is sufficiently large:

fio: page allocation failure: order:9, mode:0x140c0c0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null)
Call Trace:
dump_stack+0x63/0x88
warn_alloc+0xf5/0x190
__alloc_pages_slowpath+0x8f0/0xb0d
__alloc_pages_nodemask+0x242/0x260
alloc_pages_current+0x6a/0xb0
kmalloc_order+0x18/0x50
kmalloc_order_trace+0x26/0xb0
__kmalloc+0x20e/0x220
blkdev_report_zones_ioctl+0xa5/0x1a0
blkdev_ioctl+0x1ba/0x930
block_ioctl+0x41/0x50
do_vfs_ioctl+0xaa/0x610
SyS_ioctl+0x79/0x90
do_syscall_64+0x79/0x1b0
entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Fixes: 3ed05a987e0f ("blk-zoned: implement ioctls")
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Cc: Shaun Tancheff <shaun.tancheff@xxxxxxxxxxx>
Cc: Damien Le Moal <damien.lemoal@xxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
block/blk-zoned.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -286,7 +286,11 @@ int blkdev_report_zones_ioctl(struct blo
if (!rep.nr_zones)
return -EINVAL;

- zones = kcalloc(rep.nr_zones, sizeof(struct blk_zone), GFP_KERNEL);
+ if (rep.nr_zones > INT_MAX / sizeof(struct blk_zone))
+ return -ERANGE;
+
+ zones = kvmalloc(rep.nr_zones * sizeof(struct blk_zone),
+ GFP_KERNEL | __GFP_ZERO);
if (!zones)
return -ENOMEM;

@@ -308,7 +312,7 @@ int blkdev_report_zones_ioctl(struct blo
}

out:
- kfree(zones);
+ kvfree(zones);

return ret;
}