diff options
| author | Florian Westphal <fw@strlen.de> | 2017-07-23 19:54:47 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-07-24 16:27:08 -0700 |
| commit | a28b1b90de8322ecc45d58f1c08da12197dad17f (patch) | |
| tree | 49bc180709a0af274935ef2216ed0041fe04e579 /net/core | |
| parent | ba3fb1022154d93fe71ee78e28e195207d511bc0 (diff) | |
skbuff: re-add check for NULL skb->head in kfree_skb path
A null check is needed after all. netlink skbs can have skb->head be
backed by vmalloc. The netlink destructor vfree()s head, then sets it to
NULL. We then panic in skb_release_data with a NULL dereference.
Re-add such a test.
Alternative would be to switch to kvfree to free skb->head memory
and remove the special handling in netlink destructor.
Reported-by: kernel test robot <fengguang.wu@intel.com>
Fixes: 06dc75ab06943 ("net: Revert "net: add function to allocate sk_buff head without data area")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/skbuff.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 84bdfa229b0d..c27da51d14e4 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -638,7 +638,8 @@ void skb_release_head_state(struct sk_buff *skb) static void skb_release_all(struct sk_buff *skb) { skb_release_head_state(skb); - skb_release_data(skb); + if (likely(skb->head)) + skb_release_data(skb); } /** |