summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAndy Whitcroft <apw@canonical.com>2015-08-13 20:49:01 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-09-29 19:26:26 +0200
commite55ffaf457bcc8ec4e9d9f56f955971f834d65b3 (patch)
tree431d3b2eed69401cbd25b3fee3923f343cdc8a09
parentb21ee342590aa41e21aa0196bff5af592cc349d0 (diff)
downloadlwn-e55ffaf457bcc8ec4e9d9f56f955971f834d65b3.tar.gz
lwn-e55ffaf457bcc8ec4e9d9f56f955971f834d65b3.zip
ipv4: off-by-one in continuation handling in /proc/net/route
[ Upstream commit 25b97c016b26039982daaa2c11d83979f93b71ab ] When generating /proc/net/route we emit a header followed by a line for each route. When a short read is performed we will restart this process based on the open file descriptor. When calculating the start point we fail to take into account that the 0th entry is the header. This leads us to skip the first entry when doing a continuation read. This can be easily seen with the comparison below: while read l; do echo "$l"; done </proc/net/route >A cat /proc/net/route >B diff -bu A B | grep '^[+-]' On my example machine I have approximatly 10KB of route output. There we see the very first non-title element is lost in the while read case, and an entry around the 8K mark in the cat case: +wlan0 00000000 02021EAC 0003 0 0 400 00000000 0 0 0 -tun1 00C0AC0A 00000000 0001 0 0 950 00C0FFFF 0 0 0 Fix up the off-by-one when reaquiring position on continuation. Fixes: 8be33e955cb9 ("fib_trie: Fib walk rcu should take a tnode and key instead of a trie and a leaf") BugLink: http://bugs.launchpad.net/bugs/1483440 Acked-by: Alexander Duyck <alexander.h.duyck@redhat.com> Signed-off-by: Andy Whitcroft <apw@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/ipv4/fib_trie.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 210ceca2640c..0ca933db1b41 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -2453,7 +2453,7 @@ static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
key = l->key + 1;
iter->pos++;
- if (pos-- <= 0)
+ if (--pos <= 0)
break;
l = NULL;