[PATCH] bcachefs: add check NULL return of bio_kmalloc in journal_read_bucket

[Pei Xiao]

bio_kmalloc may return NULL, will cause NULL pointer dereference.
Add check NULL return for bio_kmalloc in journal_read_bucket.

Signed-off-by: Pei Xiao <xiaopei01@xxxxxxxxxx>
Fixes: ac10a9611d87 ("bcachefs: Some fixes for building in userspace")
---
 fs/bcachefs/errcode.h    | 1 +
 fs/bcachefs/journal_io.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/fs/bcachefs/errcode.h b/fs/bcachefs/errcode.h
index f2736e830007..ae75cb0a842c 100644
--- a/fs/bcachefs/errcode.h
+++ b/fs/bcachefs/errcode.h
@@ -83,6 +83,7 @@
 	x(ENOMEM,			ENOMEM_fs_other_alloc)			\
 	x(ENOMEM,			ENOMEM_dev_alloc)			\
 	x(ENOMEM,			ENOMEM_disk_accounting)			\
+	x(ENOMEM,                       ENOMEM_journal_read_bucket)             \
 	x(ENOSPC,			ENOSPC_disk_reservation)		\
 	x(ENOSPC,			ENOSPC_bucket_alloc)			\
 	x(ENOSPC,			ENOSPC_disk_label_add)			\
diff --git a/fs/bcachefs/journal_io.c b/fs/bcachefs/journal_io.c
index fcb68f111079..667a2bb9e20b 100644
--- a/fs/bcachefs/journal_io.c
+++ b/fs/bcachefs/journal_io.c
@@ -1014,6 +1014,8 @@ static int journal_read_bucket(struct bch_dev *ca,
 			nr_bvecs = buf_pages(buf->data, sectors_read << 9);
 
 			bio = bio_kmalloc(nr_bvecs, GFP_KERNEL);
+			if (!bio)
+				return -BCH_ERR_ENOMEM_journal_read_bucket;
 			bio_init(bio, ca->disk_sb.bdev, bio->bi_inline_vecs, nr_bvecs, REQ_OP_READ);
 
 			bio->bi_iter.bi_sector = offset;
-- 
2.34.1