[PATCH 6.4 484/800] powerpc/powernv/sriov: perform null check on iov before dereferencing iov

Greg Kroah-Hartman
2023-07-16T20:15:32Z

From: Colin Ian King <colin.i.king@gmail.com>

[ Upstream commit f4f913c980bc6abe0ccfe88fe3909c125afe4a2d ]

Currently pointer iov is being dereferenced before the null check of iov
which can lead to null pointer dereference errors. Fix this by moving the
iov null check before the dereferencing.

Detected using cppcheck static analysis:
linux/arch/powerpc/platforms/powernv/pci-sriov.c:597:12: warning: Either
the condition '!iov' is redundant or there is possible null pointer
dereference: iov. [nullPointerRedundantCheck]
num_vfs = iov->num_vfs;
^

Fixes: 052da31d45fc ("powerpc/powernv/sriov: De-indent setup and teardown")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230608095849.1147969-1-colin.i.king@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/platforms/powernv/pci-sriov.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-sriov.c b/arch/powerpc/platforms/powernv/pci-sriov.c
index 7195133b26bb9..59882da3e7425 100644
--- a/arch/powerpc/platforms/powernv/pci-sriov.c
+++ b/arch/powerpc/platforms/powernv/pci-sriov.c
@@ -594,12 +594,12 @@ static void pnv_pci_sriov_disable(struct pci_dev *pdev)
struct pnv_iov_data *iov;

iov = pnv_iov_get(pdev);
- num_vfs = iov->num_vfs;
- base_pe = iov->vf_pe_arr[0].pe_number;
-
if (WARN_ON(!iov))
return;

+ num_vfs = iov->num_vfs;
+ base_pe = iov->vf_pe_arr[0].pe_number;
+
/* Release VF PEs */
pnv_ioda_release_vf_PE(pdev);

--
2.39.2