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authorJonas Gorski <jonas.gorski@gmail.com>2023-09-10 11:34:17 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-11-20 13:59:18 +0300
commitd84a038fa4b3073f5045006ed5b8d8eff30de4dc (patch)
tree3d0724abd353af792df3dc6ddaf7deac88669988
parentd0f3994c6a40bcdcf8a2e3ce9b4653e323a44335 (diff)
downloadlinux-d84a038fa4b3073f5045006ed5b8d8eff30de4dc.tar.xz
hwrng: geode - fix accessing registers
[ Upstream commit 464bd8ec2f06707f3773676a1bd2c64832a3c805 ] When the membase and pci_dev pointer were moved to a new struct in priv, the actual membase users were left untouched, and they started reading out arbitrary memory behind the struct instead of registers. This unfortunately turned the RNG into a constant number generator, depending on the content of what was at that offset. To fix this, update geode_rng_data_{read,present}() to also get the membase via amd_geode_priv, and properly read from the right addresses again. Fixes: 9f6ec8dc574e ("hwrng: geode - Fix PCI device refcount leak") Reported-by: Timur I. Davletshin <timur.davletshin@gmail.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217882 Tested-by: Timur I. Davletshin <timur.davletshin@gmail.com> Suggested-by: Jo-Philipp Wich <jo@mein.io> Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/char/hw_random/geode-rng.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/char/hw_random/geode-rng.c b/drivers/char/hw_random/geode-rng.c
index 12fbe8091831..159baf00a867 100644
--- a/drivers/char/hw_random/geode-rng.c
+++ b/drivers/char/hw_random/geode-rng.c
@@ -58,7 +58,8 @@ struct amd_geode_priv {
static int geode_rng_data_read(struct hwrng *rng, u32 *data)
{
- void __iomem *mem = (void __iomem *)rng->priv;
+ struct amd_geode_priv *priv = (struct amd_geode_priv *)rng->priv;
+ void __iomem *mem = priv->membase;
*data = readl(mem + GEODE_RNG_DATA_REG);
@@ -67,7 +68,8 @@ static int geode_rng_data_read(struct hwrng *rng, u32 *data)
static int geode_rng_data_present(struct hwrng *rng, int wait)
{
- void __iomem *mem = (void __iomem *)rng->priv;
+ struct amd_geode_priv *priv = (struct amd_geode_priv *)rng->priv;
+ void __iomem *mem = priv->membase;
int data, i;
for (i = 0; i < 20; i++) {