4.19-stable review patch. If anyone has any objections, please let me know.
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From: Jonas Gorski jonas.gorski@gmail.com
[ 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 --- drivers/char/hw_random/geode-rng.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/char/hw_random/geode-rng.c b/drivers/char/hw_random/geode-rng.c index 207272979f233..2f8289865ec81 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++) {