Messages in this thread | | | Subject | Re: [PATCH IPV6 1/1] ipv6: allocate enough headroom in ip6_finish_output2() | From | Eric Dumazet <> | Date | Wed, 7 Jul 2021 20:50:22 +0200 |
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On 7/7/21 8:30 PM, Jakub Kicinski wrote: > On Wed, 7 Jul 2021 19:41:44 +0200 Eric Dumazet wrote: >> On 7/7/21 6:42 PM, Jakub Kicinski wrote: >>> On Wed, 7 Jul 2021 08:45:13 -0600 David Ahern wrote: >>>> why not use hh_len here? >>> >>> Is there a reason for the new skb? Why not pskb_expand_head()? >> >> >> pskb_expand_head() might crash, if skb is shared. >> >> We possibly can add a helper, factorizing all this, >> and eventually use pskb_expand_head() if safe. > > Is there a strategically placed skb_share_check() somewhere further > down? Otherwise there seems to be a lot of questionable skb_cow*() > calls, also __skb_linearize() and skb_pad() are risky, no? > Or is it that shared skbs are uncommon and syzbot doesn't hit them? >
Some of us try hard to remove skb_get() occurrences, but they tend to re-appear fast :/
Refs: commit a516993f0ac1694673412eb2d16a091eafa77d2a ("net: fix wrong skb_get() usage / crash in IGMP/MLD parsing code")
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