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Miller" , "David Ahern" , "Eric Dumazet" , "Jakub Kicinski" , "Paolo Abeni" Cc: "Simon Horman" , , , "Xiang Mei" X-Mailer: aerc 0.21.0 References: <20260617065512.2529757-2-bestswngs@gmail.com> In-Reply-To: On Wed Jun 17, 2026 at 4:32 PM CST, Jiayuan Chen wrote: > > On 6/17/26 2:55 PM, Weiming Shi wrote: >> accept_untracked_na() re-fetches the inet6_dev with __in6_dev_get(dev) >> and dereferences idev->cnf.accept_untracked_na without a NULL check, > > > Does ipv6_rpl_srh_rcv have same problem? Hi, Yes, ipv6_rpl_srh_rcv() has the same missing check. It reads idev->cnf.rpl_seg_enabled right after __in6_dev_get(skb->dev) with no NULL check, while seg6 and ioam6 in the same file both check it. But I tried to trigger it and couldn't. With a guard added as an instrument= , idev never came back NULL over tens of millions of RPL packets while flapping the MTU, so I can't say it's actually reachable. Still, it's the only one of the three without the check. Want me to send a patch adding it there too, for consistency? Thanks, Weiming Shi