[PATCH v2] erofs: fix kvcalloc() misuse with __GFP_NOFAIL

Gao Xiang
2023-01-10T07:49:46Z

As reported by syzbot [1], kvcalloc() cannot work with __GFP_NOFAIL.
Let's use kcalloc() instead.

[1] https://lore.kernel.org/r/0000000000007796bd05f1852ec2@google.com
Reported-by: syzbot+c3729cda01706a04fb98@syzkaller.appspotmail.com
Fixes: fe3e5914e6dc ("erofs: try to leave (de)compressed_pages on stack if possible")
Fixes: 4f05687fd703 ("erofs: introduce struct z_erofs_decompress_backend")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
changes since v1:
- should use kfree() instead of kvfree() as well (Chao);
- add Chao's r-v-b.

fs/erofs/zdata.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index ccf7c55d477f..5200bb86e264 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1032,12 +1032,12 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,

if (!be->decompressed_pages)
be->decompressed_pages =
- kvcalloc(be->nr_pages, sizeof(struct page *),
- GFP_KERNEL | __GFP_NOFAIL);
+ kcalloc(be->nr_pages, sizeof(struct page *),
+ GFP_KERNEL | __GFP_NOFAIL);
if (!be->compressed_pages)
be->compressed_pages =
- kvcalloc(pclusterpages, sizeof(struct page *),
- GFP_KERNEL | __GFP_NOFAIL);
+ kcalloc(pclusterpages, sizeof(struct page *),
+ GFP_KERNEL | __GFP_NOFAIL);

z_erofs_parse_out_bvecs(be);
err2 = z_erofs_parse_in_bvecs(be, &overlapped);
@@ -1085,7 +1085,7 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
}
if (be->compressed_pages < be->onstack_pages ||
be->compressed_pages >= be->onstack_pages + Z_EROFS_ONSTACK_PAGES)
- kvfree(be->compressed_pages);
+ kfree(be->compressed_pages);
z_erofs_fill_other_copies(be, err);

for (i = 0; i < be->nr_pages; ++i) {
@@ -1104,7 +1104,7 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
}

if (be->decompressed_pages != be->onstack_pages)
- kvfree(be->decompressed_pages);
+ kfree(be->decompressed_pages);

pcl->length = 0;
pcl->partial = true;
--
2.24.4