diff options
| author | Kyle Zeng <zengyhkyle@gmail.com> | 2023-09-14 22:12:57 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-09-17 15:14:58 +0100 |
| commit | 0113d9c9d1ccc07f5a3710dac4aa24b6d711278c (patch) | |
| tree | 617a53dcdcbb3f983b0ef70f17a4e1fced5c86b0 /net | |
| parent | cb47b1f679c4d83a5fa5f1852e472f844e41a3da (diff) | |
ipv4: fix null-deref in ipv4_link_failure
Currently, we assume the skb is associated with a device before calling
__ip_options_compile, which is not always the case if it is re-routed by
ipvs.
When skb->dev is NULL, dev_net(skb->dev) will become null-dereference.
This patch adds a check for the edge case and switch to use the net_device
from the rtable when skb->dev is NULL.
Fixes: ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure")
Suggested-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Kyle Zeng <zengyhkyle@gmail.com>
Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
Cc: Vadim Fedorenko <vfedorenko@novek.ru>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/route.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 66f419e7f9a7..a57062283219 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1213,6 +1213,7 @@ EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); static void ipv4_send_dest_unreach(struct sk_buff *skb) { + struct net_device *dev; struct ip_options opt; int res; @@ -1230,7 +1231,8 @@ static void ipv4_send_dest_unreach(struct sk_buff *skb) opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); rcu_read_lock(); - res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); + dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; + res = __ip_options_compile(dev_net(dev), &opt, skb, NULL); rcu_read_unlock(); if (res) |