From: Vasily Averin <vvs@xxxxxxxxxxxxx>
If .next function does not change position index,
following .show function will repeat output related
to current position index.
Without patch:
# dd if=/proc/net/ip_tables_matches # original file output
conntrack
conntrack
conntrack
recent
recent
icmp
udplite
udp
tcp
0+1 records in
0+1 records out
65 bytes copied, 5.4074e-05 s, 1.2 MB/s
# dd if=/proc/net/ip_tables_matches bs=62 skip=1
dd: /proc/net/ip_tables_matches: cannot skip to specified offset
cp <<< end of last line
tcp <<< and then unexpected whole last line once again
0+1 records in
0+1 records out
7 bytes copied, 0.000102447 s, 68.3 kB/s
Cc: stable@xxxxxxxxxxxxxxx
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@xxxxxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/x_tables.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index e27c6c5ba9df..cd2b034eef59 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -1551,6 +1551,9 @@ static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
uint8_t nfproto = (unsigned long)PDE_DATA(file_inode(seq->file));
struct nf_mttg_trav *trav = seq->private;
+ if (ppos != NULL)
+ ++(*ppos);
+
switch (trav->class) {
case MTTG_TRAV_INIT:
trav->class = MTTG_TRAV_NFP_UNSPEC;
@@ -1576,9 +1579,6 @@ static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
default:
return NULL;
}
-
- if (ppos != NULL)
- ++*ppos;
return trav;
}
--
2.11.0
