Bug 69341

bugzilla-daemon@bugzilla.kernel.org schrieb:
>https://bugzilla.kernel.org/show_bug.cgi?id=69341
>
>            Bug ID: 69341
>           Summary: Kernel BUG/Panic deleting chain used in jump in
>                    nftables
>           Product: Networking
>           Version: 2.5
>    Kernel Version: 3.13.0
>          Hardware: x86-64
>                OS: Linux
>              Tree: Fedora
>            Status: NEW
>          Severity: high
>          Priority: P1
>         Component: Netfilter/Iptables
>          Assignee: networking_netfilter-iptables@kernel-bugs.osdl.org
>          Reporter: deleriux1@gmail.com
>        Regression: No
>
>Creating a rule that jumps to a chain which you subsequently delete
>will
>result in the kernel throwing a BUG message with the following:
>
>kernel BUG at net/netfilter/nf_tables_api.c:1014!
>invalid opcode: 0000 [#1] SMP
>Modules linked in: nft_meta nft_reject_ipv4 nft_hash nft_rbtree
>nf_tables_ipv4_
>
>The host displays no more console output suggesting a panic however the
>console
>is no longer responsive and does not respond to ping.
>
>Here is the interactive session I used.
>
># nft -i
>nft> add table filter
>nft> add chain filter input { type filter hook input priority 0; }
>nft> add chain filter test 
>nft> add rule filter input jump test
>nft> delete chain filter test
>
>-- 
>You are receiving this mail because:
>You are watching the assignee of the bug.

Thx, I've queued up a fix. Currently travelling, will send it later today.

Created attachment 123291 [details]
Check chain use count before allowing deletion

Here we go. Please test whether this fixes the problem. Thanks.

Looks good. The two mechs that I was able to cause this problem have gone away. Provided the new transcript in case it is reporting anything you dont expect.

nft> add table filter
nft> add chain ip filter input { type filter hook input priority 0; }
nft> add chain ip filter test
nft> add rule ip filter input jump test
nft> delete chain ip filter test
<cli>:1:1-27: Error: Could not delete chain: Device or resource busy
delete chain ip filter test
^^^^^^^^^^^^^^^^^^^^^^^^^^^


nft> add map filter mymap { type ifindex : verdict ; }
nft> add element filter mymap { lo : jump test }
nft> add element filter mymap { eth0 : jump test }
nft> list table filter
table ip filter {
	map mymap {
		type ifindex : verdict
		elements = { eth0 : jump test, lo : jump test}
	}

	chain input {
		 type filter hook input priority 0;
		 jump test # handle 3
	}

	chain test {
	}
}
nft> delete rule filter input handle 3
nft> delete chain ip filter test
<cli>:1:1-27: Error: Could not delete chain: Device or resource busy
delete chain ip filter test
^^^^^^^^^^^^^^^^^^^^^^^^^^^

Thanks, patch pushed upstream.