From: Wenwen Wang wenwen@cs.uga.edu
[ Upstream commit 15a78ba1844a8e052c1226f930133de4cef4e7ad ]
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: Wenwen Wang wenwen@cs.uga.edu Reviewed-by: Florian Westphal fw@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/bridge/netfilter/ebtables.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 1a87cf78fadc4..d9471e3ef2161 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -2280,8 +2280,10 @@ static int compat_do_replace(struct net *net, void __user *user, state.buf_kern_len = size64;
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; + }
vfree(entries_tmp); tmp.entries_size = size64;