| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.5 081/151] netfilter: xt_recent: recent_seq_next should increase position index | Date | Tue, 17 Mar 2020 11:54:51 +0100 |
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From: Vasily Averin <vvs@virtuozzo.com>
commit db25517a550926f609c63054b12ea9ad515e1a10 upstream.
If .next function does not change position index, following .show function will repeat output related to current position index.
Without the patch: # dd if=/proc/net/xt_recent/SSH # original file outpt src=127.0.0.4 ttl: 0 last_seen: 6275444819 oldest_pkt: 1 6275444819 src=127.0.0.2 ttl: 0 last_seen: 6275438906 oldest_pkt: 1 6275438906 src=127.0.0.3 ttl: 0 last_seen: 6275441953 oldest_pkt: 1 6275441953 0+1 records in 0+1 records out 204 bytes copied, 6.1332e-05 s, 3.3 MB/s
Read after lseek into middle of last line (offset 140 in example below) generates expected end of last line and then unexpected whole last line once again
# dd if=/proc/net/xt_recent/SSH bs=140 skip=1 dd: /proc/net/xt_recent/SSH: cannot skip to specified offset 127.0.0.3 ttl: 0 last_seen: 6275441953 oldest_pkt: 1 6275441953 src=127.0.0.3 ttl: 0 last_seen: 6275441953 oldest_pkt: 1 6275441953 0+1 records in 0+1 records out 132 bytes copied, 6.2487e-05 s, 2.1 MB/s
Cc: stable@vger.kernel.org Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code ...") Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- net/netfilter/xt_recent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -492,12 +492,12 @@ static void *recent_seq_next(struct seq_ const struct recent_entry *e = v; const struct list_head *head = e->list.next; + (*pos)++; while (head == &t->iphash[st->bucket]) { if (++st->bucket >= ip_list_hash_size) return NULL; head = t->iphash[st->bucket].next; } - (*pos)++; return list_entry(head, struct recent_entry, list); }
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