Hello stable kernel maintainers,

Please backport patch 327ea4adcfa3 ("blkdev_report_zones_ioctl(): Use vmalloc() to allocate large buffers") to at least the v4.17.x and v4.14.y stable kernel series. That patch fixes a bug introduced in kernel v4.10. The entire patch is shown below.

Thanks,

Bart.

commit cf0110698846fc5a93df89eb20ac7cc70a860c17 Author: Bart Van Assche bart.vanassche@wdc.com Date: Tue May 22 08:27:22 2018 -0700

blkdev_report_zones_ioctl(): Use vmalloc() to allocate large buffers

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@wdc.com Cc: Shaun Tancheff shaun.tancheff@seagate.com Cc: Damien Le Moal damien.lemoal@hgst.com Cc: Christoph Hellwig hch@lst.de Cc: Martin K. Petersen martin.petersen@oracle.com Cc: Hannes Reinecke hare@suse.com Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe axboe@kernel.dk

diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 08e84ef2bc05..3d08dc84db16 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -328,7 +328,11 @@ int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode, 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;

@@ -350,7 +354,7 @@ int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode, }

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

return ret; }