releases/6.6.26/dma-buf-fix-null-pointer-dereference-in-sanitycheck.patch

   1 From 5926e9c05d611bdbc57686f05f37f0ba9591f831 Mon Sep 17 00:00:00 2001
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Wed, 20 Mar 2024 04:15:23 +0500
   4 Subject: dma-buf: Fix NULL pointer dereference in sanitycheck()
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 From: Pavel Sakharov <p.sakharov@ispras.ru>
  10
  11 [ Upstream commit 2295bd846765c766701e666ed2e4b35396be25e6 ]
  12
  13 If due to a memory allocation failure mock_chain() returns NULL, it is
  14 passed to dma_fence_enable_sw_signaling() resulting in NULL pointer
  15 dereference there.
  16
  17 Call dma_fence_enable_sw_signaling() only if mock_chain() succeeds.
  18
  19 Found by Linux Verification Center (linuxtesting.org) with SVACE.
  20
  21 Fixes: d62c43a953ce ("dma-buf: Enable signaling on fence for selftests")
  22 Signed-off-by: Pavel Sakharov <p.sakharov@ispras.ru>
  23 Reviewed-by: Christian König <christian.koenig@amd.com>
  24 Signed-off-by: Christian König <christian.koenig@amd.com>
  25 Link: https://patchwork.freedesktop.org/patch/msgid/20240319231527.1821372-1-p.sakharov@ispras.ru
  26 Signed-off-by: Sasha Levin <sashal@kernel.org>
  27 ---
  28  drivers/dma-buf/st-dma-fence-chain.c | 6 +++---
  29  1 file changed, 3 insertions(+), 3 deletions(-)
  30
  31 diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c
  32 index c0979c8049b5a..661de4add4c72 100644
  33 --- a/drivers/dma-buf/st-dma-fence-chain.c
  34 +++ b/drivers/dma-buf/st-dma-fence-chain.c
  35 @@ -84,11 +84,11 @@ static int sanitycheck(void *arg)
  36                 return -ENOMEM;
  37
  38         chain = mock_chain(NULL, f, 1);
  39 -       if (!chain)
  40 +       if (chain)
  41 +               dma_fence_enable_sw_signaling(chain);
  42 +       else
  43                 err = -ENOMEM;
  44
  45 -       dma_fence_enable_sw_signaling(chain);
  46 -
  47         dma_fence_signal(f);
  48         dma_fence_put(f);
  49
  50 --
  51 2.43.0
  52