From: Gao Xiang gaoxiang25@huawei.com
commit e12a0ce2fa69798194f3a8628baf6edfbd5c548f upstream.
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 Reviewed-by: Chao Yu yuchao0@huawei.com Link: https://lore.kernel.org/r/20190821140152.229648-1-gaoxiang25@huawei.com [ Gao Xiang: Since earlier kernels don't define EFSCORRUPTED, let's use EIO instead. ] Signed-off-by: Gao Xiang gaoxiang25@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/erofs/unzip_vle.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)
--- a/drivers/staging/erofs/unzip_vle.c +++ b/drivers/staging/erofs/unzip_vle.c @@ -943,6 +943,7 @@ repeat: for (i = 0; i < nr_pages; ++i) pages[i] = NULL;
+ err = 0; z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS, work->pagevec, 0);
@@ -964,8 +965,17 @@ repeat: 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 (pages[pagenr]) { + DBG_BUGON(1); + SetPageError(pages[pagenr]); + z_erofs_onlinepage_endio(pages[pagenr]); + err = -EIO; + } pages[pagenr] = page; } sparsemem_pages = i; @@ -975,7 +985,6 @@ repeat: overlapped = false; compressed_pages = grp->compressed_pages;
- err = 0; for (i = 0; i < clusterpages; ++i) { unsigned int pagenr;
@@ -999,7 +1008,12 @@ repeat: pagenr = z_erofs_onlinepage_index(page);
DBG_BUGON(pagenr >= nr_pages); - DBG_BUGON(pages[pagenr]); + if (pages[pagenr]) { + DBG_BUGON(1); + SetPageError(pages[pagenr]); + z_erofs_onlinepage_endio(pages[pagenr]); + err = -EIO; + } ++sparsemem_pages; pages[pagenr] = page;