| Message ID | 2d891aec-874a-62b9-6527-bb7306f9c4fd@virtuozzo.com |
|---|---|
| State | Accepted |
| Delegated to: | Pablo Neira |
| Headers | show |
| Series | netfilter: seq_file .next functions should increase position index | expand |
diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c index 0a97080..225a7ab 100644 --- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -492,12 +492,12 @@ static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos) 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); }
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> --- net/netfilter/xt_recent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)