linux-kernel - [PATCH 8/8] nvmem: properly handle returned value nvmem_reg

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 11 May 2018 12:07:03 +0100
From:   Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
To:     gregkh@...uxfoundation.org
Cc:     linux-kernel@...r.kernel.org, srinivas.kandagatla@...aro.org,
        Mathieu Malaterre <malat@...ian.org>
Subject: [PATCH 8/8] nvmem: properly handle returned value nvmem_reg_read

From: Mathieu Malaterre <malat@...ian.org>

Function nvmem_reg_read can return a non zero value indicating an error.
This returned value must be read and error propagated to
nvmem_cell_prepare_write_buffer. Silence the following gcc warning (W=1):

drivers/nvmem/core.c:1093:9: warning: variable 'rc' set but
 not used [-Wunused-but-set-variable]

Signed-off-by: Mathieu Malaterre <malat@...ian.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
---
 drivers/nvmem/core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 36361044ddbe..b5b0cdc21d01 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -1119,6 +1119,8 @@ static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell,
 
 		/* setup the first byte with lsb bits from nvmem */
 		rc = nvmem_reg_read(nvmem, cell->offset, &v, 1);
+		if (rc)
+			goto err;
 		*b++ |= GENMASK(bit_offset - 1, 0) & v;
 
 		/* setup rest of the byte if any */
@@ -1137,11 +1139,16 @@ static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell,
 		/* setup the last byte with msb bits from nvmem */
 		rc = nvmem_reg_read(nvmem,
 				    cell->offset + cell->bytes - 1, &v, 1);
+		if (rc)
+			goto err;
 		*p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v;
 
 	}
 
 	return buf;
+err:
+	kfree(buf);
+	return ERR_PTR(rc);
 }
 
 /**
-- 
2.16.2