public inbox for linux-next@vger.kernel.org
 help / color / mirror / Atom feed
From: coverity-bot <keescook@chromium.org>
To: Richard Guy Briggs <rgb@redhat.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>,
	Paul Moore <paul@paul-moore.com>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
	linux-next@vger.kernel.org
Subject: Coverity: nf_tables_commit(): USE_AFTER_FREE
Date: Wed, 31 Mar 2021 15:03:30 -0700	[thread overview]
Message-ID: <202103311502.EDF441BE1@keescook> (raw)

Hello!

This is an experimental semi-automated report about issues detected by
Coverity from a scan of next-20210331 as part of the linux-next scan project:
https://scan.coverity.com/projects/linux-next-weekly-scan

You're getting this email because you were associated with the identified
lines of code (noted below) that were touched by commits:

  None
    bb4052e57b5b ("audit: log nftables configuration change events once per table")

Coverity reported the following:

*** CID 1503581:    (USE_AFTER_FREE)
/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);

Notes from a human:

This appears to be callable after potential calls to "nft_trans_destroy(trans);"



/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
/net/netfilter/nf_tables_api.c: 8257 in nf_tables_commit()
8251     							   NFT_MSG_DELFLOWTABLE);
8252     				nft_unregister_flowtable_net_hooks(net,
8253     						&nft_trans_flowtable(trans)->hook_list);
8254     			}
8255     			break;
8256     		}
vvv     CID 1503581:    (USE_AFTER_FREE)
vvv     Dereferencing freed pointer "trans".
8257     		nf_tables_commit_audit_collect(&adl, trans->ctx.table,
8258     					       trans->msg_type);
8259     	}
8260
8261     	nft_commit_notify(net, NETLINK_CB(skb).portid);
8262     	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);

If this is a false positive, please let us know so we can mark it as
such, or teach the Coverity rules to be smarter. If not, please make
sure fixes get into linux-next. :) For patches fixing this, please
include these lines (but double-check the "Fixes" first):

Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1503581 ("USE_AFTER_FREE")
Fixes: bb4052e57b5b ("audit: log nftables configuration change events once per table")

Thanks for your attention!

-- 
Coverity-bot

                 reply	other threads:[~2021-03-31 22:04 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=202103311502.EDF441BE1@keescook \
    --to=keescook@chromium.org \
    --cc=gustavo@embeddedor.com \
    --cc=linux-next@vger.kernel.org \
    --cc=pablo@netfilter.org \
    --cc=paul@paul-moore.com \
    --cc=rgb@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox