4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chao Yu <yuchao0@xxxxxxxxxx>
commit 8bce6dcede65139a087ff240127e3f3c01363eed upstream.
erofs_vmap() wrapped vmap() and vm_map_ram() to return virtual
continuous memory, but both of them can failed due to a lot of
reason, previously, erofs_vmap()'s callers didn't handle them,
which can potentially cause NULL pointer access, fix it.
Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support")
Fixes: 0d40d6e399c1 ("staging: erofs: add a generic z_erofs VLE decompressor")
Cc: <stable@xxxxxxxxxxxxxxx> # 4.19+
Signed-off-by: Gao Xiang <gaoxiang25@xxxxxxxxxx>
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/erofs/unzip_vle.c | 4 ++++
drivers/staging/erofs/unzip_vle_lz4.c | 7 +++++--
2 files changed, 9 insertions(+), 2 deletions(-)
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -942,6 +942,10 @@ repeat:
skip_allocpage:
vout = erofs_vmap(pages, nr_pages);
+ if (!vout) {
+ err = -ENOMEM;
+ goto out;
+ }
err = z_erofs_vle_unzip_vmap(compressed_pages,
clusterpages, vout, llen, work->pageofs, overlapped);
--- a/drivers/staging/erofs/unzip_vle_lz4.c
+++ b/drivers/staging/erofs/unzip_vle_lz4.c
@@ -116,10 +116,13 @@ int z_erofs_vle_unzip_fast_percpu(struct
nr_pages = DIV_ROUND_UP(outlen + pageofs, PAGE_SIZE);
- if (clusterpages == 1)
+ if (clusterpages == 1) {
vin = kmap_atomic(compressed_pages[0]);
- else
+ } else {
vin = erofs_vmap(compressed_pages, clusterpages);
+ if (!vin)
+ return -ENOMEM;
+ }
preempt_disable();
vout = erofs_pcpubuf[smp_processor_id()].data;
