Commit 15a78ba1 authored by Wenwen Wang's avatar Wenwen Wang Committed by Pablo Neira Ayuso

netfilter: ebtables: fix a memory leak bug in compat

In compat_do_replace(), a temporary buffer is allocated through vmalloc()
to hold entries copied from the user space. The buffer address is firstly
saved to 'newinfo->entries', and later on assigned to 'entries_tmp'. Then
the entries in this temporary buffer is copied to the internal kernel
structure through compat_copy_entries(). If this copy process fails,
compat_do_replace() should be terminated. However, the allocated temporary
buffer is not freed on this path, leading to a memory leak.

To fix the bug, free the buffer before returning from compat_do_replace().
Signed-off-by: default avatarWenwen Wang <wenwen@cs.uga.edu>
Reviewed-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 0cea0e11
...@@ -2261,8 +2261,10 @@ static int compat_do_replace(struct net *net, void __user *user, ...@@ -2261,8 +2261,10 @@ static int compat_do_replace(struct net *net, void __user *user,
state.buf_kern_len = size64; state.buf_kern_len = size64;
ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state); ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
if (WARN_ON(ret < 0)) if (WARN_ON(ret < 0)) {
vfree(entries_tmp);
goto out_unlock; goto out_unlock;
}
vfree(entries_tmp); vfree(entries_tmp);
tmp.entries_size = size64; tmp.entries_size = size64;
......
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