From 9701a8a0dd9421f7788792958c66c46eb0c067f6 Mon Sep 17 00:00:00 2001
From: Sergey Senozhatsky <senozhatsky@chromium.org>
Date: Fri, 12 Jul 2024 14:18:14 +0900
Subject: [PATCH] lib: zstd: fix null-deref in ZSTD_createCDict_advanced2()

ZSTD_createCDict_advanced2() must ensure that
ZSTD_createCDict_advanced_internal() has successfully
allocated cdict.  customMalloc() may be called under
low memory condition and may be unable to allocate
workspace for cdict.

Link: https://lkml.kernel.org/r/20240712051850.484318-4-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 lib/zstd/compress/zstd_compress.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/zstd/compress/zstd_compress.c b/lib/zstd/compress/zstd_compress.c
index f620cafca633..16bb995bc6c4 100644
--- a/lib/zstd/compress/zstd_compress.c
+++ b/lib/zstd/compress/zstd_compress.c
@@ -4810,6 +4810,8 @@ ZSTD_CDict* ZSTD_createCDict_advanced2(
                         dictLoadMethod, cctxParams.cParams,
                         cctxParams.useRowMatchFinder, cctxParams.enableDedicatedDictSearch,
                         customMem);
+    if (!cdict)
+        return NULL;
 
     if (ZSTD_isError( ZSTD_initCDict_internal(cdict,
                                     dict, dictSize,
-- 
2.50.1