[PATCH] Fix keyctl usage of strnlen_user()

In the small window between strnlen_user() and copy_from_user() userspace
could alter the terminating `\0' character.

Signed-off-by: Davi Arnaut <davi.arnaut@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Davi Arnaut 2006-02-03 03:04:46 -08:00 committed by Linus Torvalds
parent 353368dffb
commit 6d94074f08

View file

@ -67,9 +67,10 @@ asmlinkage long sys_add_key(const char __user *_type,
description = kmalloc(dlen + 1, GFP_KERNEL);
if (!description)
goto error;
description[dlen] = '\0';
ret = -EFAULT;
if (copy_from_user(description, _description, dlen + 1) != 0)
if (copy_from_user(description, _description, dlen) != 0)
goto error2;
/* pull the payload in if one was supplied */
@ -161,9 +162,10 @@ asmlinkage long sys_request_key(const char __user *_type,
description = kmalloc(dlen + 1, GFP_KERNEL);
if (!description)
goto error;
description[dlen] = '\0';
ret = -EFAULT;
if (copy_from_user(description, _description, dlen + 1) != 0)
if (copy_from_user(description, _description, dlen) != 0)
goto error2;
/* pull the callout info into kernel space */
@ -182,9 +184,10 @@ asmlinkage long sys_request_key(const char __user *_type,
callout_info = kmalloc(dlen + 1, GFP_KERNEL);
if (!callout_info)
goto error2;
callout_info[dlen] = '\0';
ret = -EFAULT;
if (copy_from_user(callout_info, _callout_info, dlen + 1) != 0)
if (copy_from_user(callout_info, _callout_info, dlen) != 0)
goto error3;
}
@ -279,9 +282,10 @@ long keyctl_join_session_keyring(const char __user *_name)
name = kmalloc(nlen + 1, GFP_KERNEL);
if (!name)
goto error;
name[nlen] = '\0';
ret = -EFAULT;
if (copy_from_user(name, _name, nlen + 1) != 0)
if (copy_from_user(name, _name, nlen) != 0)
goto error2;
}
@ -583,9 +587,10 @@ long keyctl_keyring_search(key_serial_t ringid,
description = kmalloc(dlen + 1, GFP_KERNEL);
if (!description)
goto error;
description[dlen] = '\0';
ret = -EFAULT;
if (copy_from_user(description, _description, dlen + 1) != 0)
if (copy_from_user(description, _description, dlen) != 0)
goto error2;
/* get the keyring at which to begin the search */