prctl: Return -EFAULT on auxv fetching failure

PATCH New Cyrill Gorcunov 1 participant 1 message Aug 27, 2014

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Cyrill Gorcunov

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2014-08-27 11:03 UTC #0 lore raw

PATCH 1/1 prctl: Return -EFAULT on auxv fetching failure

Dan reported that returning bytes left if copy_from_user failed is a bad option, return traditional -EFAULT instead.

Reported-by Dan Carpenter <[email protected]>

Cc Andrew Morton <[email protected]>

Signed-off-by Cyrill Gorcunov <[email protected]>

---
Dan, this is not for current linux-next, but for Andrew's -mm queue, since he has prctl code already updated with v4 of the former patch.

 kernel/sys.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

kernel/sys.c +4 -5

Index: linux-2.6.git/kernel/sys.c
===================================================================
@@ -1814,11 +1814,10 @@ static int prctl_set_mm_map(int opt, con
 
 	if (prctl_map.auxv_size) {
 		memset(user_auxv, 0, sizeof(user_auxv));
-		error = copy_from_user(user_auxv,
-				       (const void __user *)prctl_map.auxv,
-				       prctl_map.auxv_size);
-		if (error)
-			return error;
+		if (copy_from_user(user_auxv,
+				   (const void __user *)prctl_map.auxv,
+				   prctl_map.auxv_size))
+			return -EFAULT;
 
 		/* Last entry must be AT_NULL as specification requires */
 		user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;