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Date:   Tue, 13 Sep 2022 19:00:01 -0700
Message-Id: <20220914020001.2846018-1-pcc@google.com>
Mime-Version: 1.0
Subject: [PATCH] kasan: call kasan_malloc() from __kmalloc_*track_caller()
From:   Peter Collingbourne <pcc@google.com>
To:     Andrey Konovalov <andreyknvl@gmail.com>,
        Hyeonggon Yoo <42.hyeyoo@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     Peter Collingbourne <pcc@google.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

We were failing to call kasan_malloc() from __kmalloc_*track_caller()
which was causing us to sometimes fail to produce KASAN error reports
for allocations made using e.g. devm_kcalloc(), as the KASAN poison was
not being initialized. Fix it.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Cc: <stable@vger.kernel.org> # 5.15
---
The same problem is being fixed upstream in:
https://lore.kernel.org/all/20220817101826.236819-6-42.hyeyoo@gmail.com/
as part of a larger patch series, but this more targeted fix seems
more suitable for the stable kernel. Hyeonggon, maybe you can add
this patch to the start of your series and it can be picked up
by the stable maintainers.

 mm/slub.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mm/slub.c b/mm/slub.c
index 862dbd9af4f5..875c569c5cbe 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4926,6 +4926,8 @@ void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
 	/* Honor the call site pointer we received. */
 	trace_kmalloc(caller, ret, s, size, s->size, gfpflags);
 
+	ret = kasan_kmalloc(s, ret, size, gfpflags);
+
 	return ret;
 }
 EXPORT_SYMBOL(__kmalloc_track_caller);
@@ -4957,6 +4959,8 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
 	/* Honor the call site pointer we received. */
 	trace_kmalloc_node(caller, ret, s, size, s->size, gfpflags, node);
 
+	ret = kasan_kmalloc(s, ret, size, gfpflags);
+
 	return ret;
 }
 EXPORT_SYMBOL(__kmalloc_node_track_caller);
-- 
2.37.2.789.g6183377224-goog