[patch 32/74] parisc: isa-eeprom - Fix loff_t usage

[Greg KH]

2.6.30-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Michael Buesch <mb@xxxxxxxxx>

commit 6b4dbcd86a9d464057fcc7abe4d0574093071fcc upstream.

loff_t is a signed type. If userspace passes a negative ppos, the "count"
range check is weakened. "count"s bigger than HPEE_MAX_LENGTH will pass the check.
Also, if ppos is negative, the readb(eisa_eeprom_addr + *ppos) will poke in random
memory.

Signed-off-by: Michael Buesch <mb@xxxxxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/parisc/eisa_eeprom.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/parisc/eisa_eeprom.c
+++ b/drivers/parisc/eisa_eeprom.c
@@ -55,7 +55,7 @@ static ssize_t eisa_eeprom_read(struct f
 	ssize_t ret;
 	int i;
 	
-	if (*ppos >= HPEE_MAX_LENGTH)
+	if (*ppos < 0 || *ppos >= HPEE_MAX_LENGTH)
 		return 0;
 	
 	count = *ppos + count < HPEE_MAX_LENGTH ? count : HPEE_MAX_LENGTH - *ppos;


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