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From: Greg KH on 30 Mar 2010 20:40
2.6.27-stable review patch. If anyone has any objections, please let us know.

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

From: Michael Buesch <mb(a)bu3sch.de>

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(a)bu3sch.de>
Signed-off-by: Helge Deller <deller(a)gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de>

---
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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