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| author | Chao Yu <yuchao0@huawei.com> | 2020-03-23 17:43:04 +0800 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2020-03-30 20:46:25 -0700 |
| commit | 79bbefb19f1359fb2cbd144d5a054649e7e583be (patch) | |
| tree | 26a75c709f304b8ba73f135a0741abf15549b6b0 /fs/f2fs | |
| parent | 23c51bed6f5d21aeebeaf9cdcd63ac3d3cbd0f83 (diff) | |
| download | linux-79bbefb19f1359fb2cbd144d5a054649e7e583be.tar.gz linux-79bbefb19f1359fb2cbd144d5a054649e7e583be.tar.bz2 linux-79bbefb19f1359fb2cbd144d5a054649e7e583be.zip | |
f2fs: fix NULL pointer dereference in f2fs_verity_work()
If both compression and fsverity feature is on, generic/572 will
report below NULL pointer dereference bug.
BUG: kernel NULL pointer dereference, address: 0000000000000018
RIP: 0010:f2fs_verity_work+0x60/0x90 [f2fs]
#PF: supervisor read access in kernel mode
Workqueue: fsverity_read_queue f2fs_verity_work [f2fs]
RIP: 0010:f2fs_verity_work+0x60/0x90 [f2fs]
Call Trace:
process_one_work+0x16c/0x3f0
worker_thread+0x4c/0x440
? rescuer_thread+0x350/0x350
kthread+0xf8/0x130
? kthread_unpark+0x70/0x70
ret_from_fork+0x35/0x40
There are two issue in f2fs_verity_work():
- it needs to traverse and verify all pages in bio.
- if pages in bio belong to non-compressed cluster, accessing
decompress IO context stored in page private will cause NULL
pointer dereference.
Fix them.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
| -rw-r--r-- | fs/f2fs/compress.c | 2 | ||||
| -rw-r--r-- | fs/f2fs/data.c | 35 |
2 files changed, 32 insertions, 5 deletions
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c index d66d372d104d..adac6fcb2830 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -477,6 +477,8 @@ out_vunmap_cbuf: out_vunmap_rbuf: vunmap(dic->rbuf); out_free_dic: + if (verity) + refcount_add(dic->nr_cpages - 1, &dic->ref); if (!verity) f2fs_decompress_end_io(dic->rpages, dic->cluster_size, ret, false); diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index bb66faf09eea..0197b7b80d19 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -187,12 +187,37 @@ static void f2fs_verify_pages(struct page **rpages, unsigned int cluster_size) static void f2fs_verify_bio(struct bio *bio) { - struct page *page = bio_first_page_all(bio); - struct decompress_io_ctx *dic = - (struct decompress_io_ctx *)page_private(page); + struct bio_vec *bv; + struct bvec_iter_all iter_all; + + bio_for_each_segment_all(bv, bio, iter_all) { + struct page *page = bv->bv_page; + struct decompress_io_ctx *dic; + + dic = (struct decompress_io_ctx *)page_private(page); + + if (dic) { + if (refcount_dec_not_one(&dic->ref)) + continue; + f2fs_verify_pages(dic->rpages, + dic->cluster_size); + f2fs_free_dic(dic); + continue; + } + + if (bio->bi_status || PageError(page)) + goto clear_uptodate; - f2fs_verify_pages(dic->rpages, dic->cluster_size); - f2fs_free_dic(dic); + if (fsverity_verify_page(page)) { + SetPageUptodate(page); + goto unlock; + } +clear_uptodate: + ClearPageUptodate(page); + ClearPageError(page); +unlock: + unlock_page(page); + } } #endif |