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md/raid0: use kvzalloc/kvfree for strip_zone and devlist allocations

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syzbot reported a WARNING at mm/page_alloc.c:__alloc_frozen_pages_noprof()
triggered by create_strip_zones() in the RAID0 driver.

When raid_disks is large, the allocation size exceeds MAX_PAGE_ORDER (4MB
on x86), causing WARN_ON_ONCE_GFP(order > MAX_PAGE_ORDER).

Convert the strip_zone and devlist allocations from kzalloc/kzalloc_objs to
kvzalloc/kvzalloc_objs, which first attempts a contiguous allocation with
__GFP_NOWARN and then falls back to vmalloc for large sizes. Convert the
corresponding kfree calls to kvfree.

Both arrays are pure metadata lookup tables (arrays of pointers and zone
descriptors) accessed only via indexing, so they do not require physically
contiguous memory.

Reported-by: syzbot+924649752adf0d3ac9dd@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/69adaba8.a00a0220.b130.0005.GAE@google.com/
Signed-off-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Yu Kuai <yukuai@fnnas.com>
Reviewed-by: Li Nan <linan122@huawei.com>
Link: https://lore.kernel.org/linux-raid/20260308234202.3118119-1-gourry@gourry.net/
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
This commit is contained in:
Gregory Price
2026-03-08 19:42:02 -04:00
committed by Yu Kuai
parent 2aa72276fa
commit 078d1d8e68
1 changed files with 9 additions and 9 deletions
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18
drivers/md/raid0.c
View File

@@ -143,13 +143,13 @@ static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
}
err = -ENOMEM;
conf->strip_zone = kzalloc_objs(struct strip_zone, conf->nr_strip_zones);
conf->strip_zone = kvzalloc_objs(struct strip_zone, conf->nr_strip_zones);
if (!conf->strip_zone)
goto abort;
conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *),
conf->nr_strip_zones,
mddev->raid_disks),
GFP_KERNEL);
conf->devlist = kvzalloc(array3_size(sizeof(struct md_rdev *),
conf->nr_strip_zones,
mddev->raid_disks),
GFP_KERNEL);
if (!conf->devlist)
goto abort;
@@ -291,8 +291,8 @@ static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
return 0;
abort:
kfree(conf->strip_zone);
kfree(conf->devlist);
kvfree(conf->strip_zone);
kvfree(conf->devlist);
kfree(conf);
*private_conf = ERR_PTR(err);
return err;
@@ -373,8 +373,8 @@ static void raid0_free(struct mddev *mddev, void *priv)
{
struct r0conf *conf = priv;
kfree(conf->strip_zone);
kfree(conf->devlist);
kvfree(conf->strip_zone);
kvfree(conf->devlist);
kfree(conf);
}