diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2022-06-02 10:15:07 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-06-02 10:15:07 -0700 |
| commit | 638696efc14729759c1d735e19e87606450b80a8 (patch) | |
| tree | 34b08ac6780f9024f3c5e61d896e96888782b5d4 | |
| parent | 83450bbafebdaf90818e77ee368202f03d056cd7 (diff) | |
| parent | e9d3f80935b6607dcdc5682b00b1d4b28e0a0c5d (diff) | |
Merge branch 'net-af_packet-be-careful-when-expanding-mac-header-size'
Eric Dumazet says:
====================
net: af_packet: be careful when expanding mac header size
A recent regression in af_packet needed a preliminary debug patch,
which will presumably be useful for next bugs hunting.
The af_packet fix is to make sure MAC headers are contained in
skb linear part, as GSO stack requests.
v2: CONFIG_DEBUG_NET depends on CONFIG_NET to avoid compile
errors found by kernel bots.
====================
Link: https://lore.kernel.org/r/20220602161859.2546399-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/linux/skbuff.h | 9 | ||||
| -rw-r--r-- | net/Kconfig.debug | 2 | ||||
| -rw-r--r-- | net/packet/af_packet.c | 6 |
3 files changed, 13 insertions, 4 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index da96f0d3e753..d3d10556f0fa 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2696,7 +2696,14 @@ void *skb_pull(struct sk_buff *skb, unsigned int len); static inline void *__skb_pull(struct sk_buff *skb, unsigned int len) { skb->len -= len; - BUG_ON(skb->len < skb->data_len); + if (unlikely(skb->len < skb->data_len)) { +#if defined(CONFIG_DEBUG_NET) + skb->len += len; + pr_err("__skb_pull(len=%u)\n", len); + skb_dump(KERN_ERR, skb, false); +#endif + BUG(); + } return skb->data += len; } diff --git a/net/Kconfig.debug b/net/Kconfig.debug index a5781cf63b16..e6ae11cc2fb7 100644 --- a/net/Kconfig.debug +++ b/net/Kconfig.debug @@ -20,7 +20,7 @@ config NET_NS_REFCNT_TRACKER config DEBUG_NET bool "Add generic networking debug" - depends on DEBUG_KERNEL + depends on DEBUG_KERNEL && NET help Enable extra sanity checks in networking. This is mostly used by fuzzers, but is safe to select. diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 677f9cfa9660..ca6e92a22923 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1935,8 +1935,10 @@ static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) /* Move network header to the right position for VLAN tagged packets */ if (likely(skb->dev->type == ARPHRD_ETHER) && eth_type_vlan(skb->protocol) && - __vlan_get_protocol(skb, skb->protocol, &depth) != 0) - skb_set_network_header(skb, depth); + __vlan_get_protocol(skb, skb->protocol, &depth) != 0) { + if (pskb_may_pull(skb, depth)) + skb_set_network_header(skb, depth); + } skb_probe_transport_header(skb); } |