diff options
| author | Kyle Zeng <zengyhkyle@gmail.com> | 2023-09-15 08:12:57 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-10-06 14:15:53 +0300 |
| commit | cda20fcddf53f0f959641c8ef4d50ab87ffa5124 (patch) | |
| tree | b9c6ec5eafb22c25ed4c9116b8b319bd15b2dc19 | |
| parent | f82def005375db03b8b0baa6a0a4086e6a675c20 (diff) | |
| download | linux-cda20fcddf53f0f959641c8ef4d50ab87ffa5124.tar.xz | |
ipv4: fix null-deref in ipv4_link_failure
[ Upstream commit 0113d9c9d1ccc07f5a3710dac4aa24b6d711278c ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 33626619aee7..0a53ca6ebb0d 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) |