@@ -798,6 +798,7 @@ static int z_erofs_decompress_pcluster(struct super_block *sb,
for (i = 0; i < nr_pages; ++i)
pages[i] = NULL;
+ err = 0;
z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS,
cl->pagevec, 0);
@@ -819,8 +820,17 @@ static int z_erofs_decompress_pcluster(struct super_block *sb,
pagenr = z_erofs_onlinepage_index(page);
DBG_BUGON(pagenr >= nr_pages);
- DBG_BUGON(pages[pagenr]);
+ /*
+ * currently EROFS doesn't support multiref(dedup),
+ * so here erroring out one multiref page.
+ */
+ if (unlikely(pages[pagenr])) {
+ DBG_BUGON(1);
+ SetPageError(pages[pagenr]);
+ z_erofs_onlinepage_endio(pages[pagenr]);
+ err = -EFSCORRUPTED;
+ }
pages[pagenr] = page;
}
z_erofs_pagevec_ctor_exit(&ctor, true);
@@ -828,7 +838,6 @@ static int z_erofs_decompress_pcluster(struct super_block *sb,
overlapped = false;
compressed_pages = pcl->compressed_pages;
- err = 0;
for (i = 0; i < clusterpages; ++i) {
unsigned int pagenr;
@@ -852,7 +861,12 @@ static int z_erofs_decompress_pcluster(struct super_block *sb,
pagenr = z_erofs_onlinepage_index(page);
DBG_BUGON(pagenr >= nr_pages);
- DBG_BUGON(pages[pagenr]);
+ if (unlikely(pages[pagenr])) {
+ DBG_BUGON(1);
+ SetPageError(pages[pagenr]);
+ z_erofs_onlinepage_endio(pages[pagenr]);
+ err = -EFSCORRUPTED;
+ }
pages[pagenr] = page;
overlapped = true;
As reported by erofs-utils fuzzer, currently, multiref (ondisk deduplication) hasn't been supported for now, we should forbid it properly. Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support") Cc: <stable@vger.kernel.org> # 4.19+ Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> --- changelog from v1: - change err = -EFSCORRUPTED as well as Chao suggested; [ the difference between adding err or not to [PATCH 5/6] is just whether we error out the whole compressed cluster or partial of them (since some pages could be decompressed successfully), it's an undefined behavior for these corrupted compressed images... ] Hi Chao, Could you kindly review it again? Thanks! Hi Greg, This is [PATCH 5/6] of the original patchset, and I fix as what Chao suggested... But I'm not sure whether it should be merged right now, it is up to you. :) Thanks, Gao Xiang drivers/staging/erofs/zdata.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)