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1e105e6afa
Following bug was reported via irc:
nft list ruleset
set knock_candidates_ipv4 {
type ipv4_addr . inet_service
size 65535
elements = { 127.0.0.1 . 123,
127.0.0.1 . 123 }
}
..
udp dport 123 add @knock_candidates_ipv4 { ip saddr . 123 }
udp dport 123 add @knock_candidates_ipv4 { ip saddr . udp dport }
It should not have been possible to add a duplicate set entry.
After some debugging it turned out that the problem is the immediate
value (123) in the second-to-last rule.
Concatenations use 32bit registers, i.e. the elements are 8 bytes each,
not 6 and it turns out the kernel inserted
inet firewall @knock_candidates_ipv4
element 0100007f ffff7b00 : 0 [end]
element 0100007f 00007b00 : 0 [end]
Note the non-zero upper bits of the first element. It turns out that
nft_immediate doesn't zero the destination register, but this is needed
when the length isn't a multiple of 4.
Furthermore, the zeroing in nft_payload is broken. We can't use
[len / 4] = 0 -- if len is a multiple of 4, index is off by one.
Skip zeroing in this case and use a conditional instead of (len -1) / 4.
Fixes:
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||
|---|---|---|
| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| dt-bindings | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| vdso | ||
| video | ||
| xen | ||