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authorGao Xiang <gaoxiang25@huawei.com>2019-08-21 16:01:52 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-08-21 18:12:42 +0200
commite12a0ce2fa69798194f3a8628baf6edfbd5c548f (patch)
tree92ea2026443650c6eee452dccdfbefe6260abf9f /drivers
parentstaging: rts5208: remove redundant assignment to retval (diff)
downloadlinux-e12a0ce2fa69798194f3a8628baf6edfbd5c548f.tar.xz
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staging: erofs: detect potential multiref due to corrupted images
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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/staging/erofs/zdata.c20
1 files changed, 17 insertions, 3 deletions
diff --git a/drivers/staging/erofs/zdata.c b/drivers/staging/erofs/zdata.c
index 4d6faaab04f5..60d7c20db87d 100644
--- a/drivers/staging/erofs/zdata.c
+++ b/drivers/staging/erofs/zdata.c
@@ -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;