commit
7ef4c19d245f3dc233fd4be5acea436edd1d83d8 upstream.
syzbot found WARNINGs in several smackfs write operations where
bytes count is passed to memdup_user_nul which exceeds
GFP MAX_ORDER. Check count size if bigger than PAGE_SIZE.
Per smackfs doc, smk_write_net4addr accepts any label or -CIPSO,
smk_write_net6addr accepts any label or -DELETE. I couldn't find
any general rule for other label lengths except SMK_LABELLEN,
SMK_LONGLABEL, SMK_CIPSOMAX which are documented.
Let's constrain, in general, smackfs label lengths for PAGE_SIZE.
Although fuzzer crashes write to smackfs/netlabel on 0x400000 length.
Here is a quick way to reproduce the WARNING:
python -c "print('A' * 0x400000)" > /sys/fs/smackfs/netlabel
Reported-by: syzbot+a71a442385a0b2815497@syzkaller.appspotmail.com
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
return -EPERM;
if (*ppos != 0)
return -EINVAL;
return -EPERM;
if (*ppos != 0)
return -EINVAL;
- if (count < SMK_NETLBLADDRMIN)
+ if (count < SMK_NETLBLADDRMIN || count > PAGE_SIZE - 1)
return -EINVAL;
data = memdup_user_nul(buf, count);
return -EINVAL;
data = memdup_user_nul(buf, count);
return -EPERM;
if (*ppos != 0)
return -EINVAL;
return -EPERM;
if (*ppos != 0)
return -EINVAL;
- if (count < SMK_NETLBLADDRMIN)
+ if (count < SMK_NETLBLADDRMIN || count > PAGE_SIZE - 1)
return -EINVAL;
data = memdup_user_nul(buf, count);
return -EINVAL;
data = memdup_user_nul(buf, count);
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
+ /* Enough data must be present */
+ if (count == 0 || count > PAGE_SIZE)
+ return -EINVAL;
+
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
+ if (count > PAGE_SIZE)
+ return -EINVAL;
+
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
+ if (count > PAGE_SIZE)
+ return -EINVAL;
+
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
+ /* Enough data must be present */
+ if (count == 0 || count > PAGE_SIZE)
+ return -EINVAL;
+
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
* Enough data must be present.
*/
if (*ppos != 0)
return -EINVAL;
* Enough data must be present.
*/
if (*ppos != 0)
return -EINVAL;
+ if (count == 0 || count > PAGE_SIZE)
+ return -EINVAL;
data = memdup_user_nul(buf, count);
if (IS_ERR(data))
data = memdup_user_nul(buf, count);
if (IS_ERR(data))