On 10/14/2019 3:16 PM, Colin King wrote:
From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Shifting a u8 left will cause the value to be promoted to an integer. If
the top bit of the u8 is set then the following conversion to a 64 bit
resource_size_t will sign extend the value causing the upper 32 bits
to be set in the result.
Fix this by casting the u8 value to a resource_size_t before the shift.
Original commit is pre-git history.
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Please resend this with a Cc to linux-acpi@xxxxxxxxxxxxxxx for easier
handling.
---
drivers/pnp/isapnp/core.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/pnp/isapnp/core.c b/drivers/pnp/isapnp/core.c
index 179b737280e1..c947b1673041 100644
--- a/drivers/pnp/isapnp/core.c
+++ b/drivers/pnp/isapnp/core.c
@@ -511,10 +511,14 @@ static void __init isapnp_parse_mem32_resource(struct pnp_dev *dev,
unsigned char flags;
isapnp_peek(tmp, size);
- min = (tmp[4] << 24) | (tmp[3] << 16) | (tmp[2] << 8) | tmp[1];
- max = (tmp[8] << 24) | (tmp[7] << 16) | (tmp[6] << 8) | tmp[5];
- align = (tmp[12] << 24) | (tmp[11] << 16) | (tmp[10] << 8) | tmp[9];
- len = (tmp[16] << 24) | (tmp[15] << 16) | (tmp[14] << 8) | tmp[13];
+ min = ((resource_size_t)tmp[4] << 24) | (tmp[3] << 16) |
+ (tmp[2] << 8) | tmp[1];
+ max = ((resource_size_t)tmp[8] << 24) | (tmp[7] << 16) |
+ (tmp[6] << 8) | tmp[5];
+ align = ((resource_size_t)tmp[12] << 24) | (tmp[11] << 16) |
+ (tmp[10] << 8) | tmp[9];
+ len = ((resource_size_t)tmp[16] << 24) | (tmp[15] << 16) |
+ (tmp[14] << 8) | tmp[13];
flags = tmp[0];
pnp_register_mem_resource(dev, option_flags,
min, max, align, len, flags);
@@ -532,8 +536,10 @@ static void __init isapnp_parse_fixed_mem32_resource(struct pnp_dev *dev,
unsigned char flags;
isapnp_peek(tmp, size);
- base = (tmp[4] << 24) | (tmp[3] << 16) | (tmp[2] << 8) | tmp[1];
- len = (tmp[8] << 24) | (tmp[7] << 16) | (tmp[6] << 8) | tmp[5];
+ base = ((resource_size_t)tmp[4] << 24) | (tmp[3] << 16) |
+ (tmp[2] << 8) | tmp[1];
+ len = ((resource_size_t)tmp[8] << 24) | (tmp[7] << 16) |
+ (tmp[6] << 8) | tmp[5];
flags = tmp[0];
pnp_register_mem_resource(dev, option_flags, base, base, 0, len, flags);
}
