diff options
| -rw-r--r-- | target/linux/generic/patches-4.1/096-ipv4-off-by-one-in-continuation-handling-in-proc-net.patch | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/target/linux/generic/patches-4.1/096-ipv4-off-by-one-in-continuation-handling-in-proc-net.patch b/target/linux/generic/patches-4.1/096-ipv4-off-by-one-in-continuation-handling-in-proc-net.patch new file mode 100644 index 0000000000..aa31641449 --- /dev/null +++ b/target/linux/generic/patches-4.1/096-ipv4-off-by-one-in-continuation-handling-in-proc-net.patch @@ -0,0 +1,46 @@ +From 25b97c016b26039982daaa2c11d83979f93b71ab Mon Sep 17 00:00:00 2001 +From: Andy Whitcroft <apw@canonical.com> +Date: Thu, 13 Aug 2015 20:49:01 +0100 +Subject: [PATCH] ipv4: off-by-one in continuation handling in /proc/net/route + +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> +--- + net/ipv4/fib_trie.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/net/ipv4/fib_trie.c ++++ b/net/ipv4/fib_trie.c +@@ -2457,7 +2457,7 @@ static struct key_vector *fib_route_get_ + key = l->key + 1; + iter->pos++; + +- if (pos-- <= 0) ++ if (--pos <= 0) + break; + + l = NULL; |