[PATCH 9/9] net, ipv4: convert fib_info.fib_clntref from atomic_t to refcount_t
From: Elena Reshetova <elena.reshetova@intel.com>
Date: 2017-03-16 18:24:18
Also in:
lkml
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <redacted> Signed-off-by: Kees Cook <redacted> Signed-off-by: David Windsor <redacted> --- include/net/ip_fib.h | 7 ++++--- net/ipv4/fib_semantics.c | 2 +- net/ipv4/fib_trie.c | 2 +- 3 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 368bb40..55d2694 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h@@ -23,6 +23,7 @@ #include <net/inetpeer.h> #include <linux/percpu.h> #include <linux/notifier.h> +#include <linux/refcount.h> struct fib_config { u8 fc_dst_len;
@@ -105,7 +106,7 @@ struct fib_info { struct hlist_node fib_lhash; struct net *fib_net; int fib_treeref; - atomic_t fib_clntref; + refcount_t fib_clntref; unsigned int fib_flags; unsigned char fib_dead; unsigned char fib_protocol;
@@ -407,12 +408,12 @@ void free_fib_info(struct fib_info *fi); static inline void fib_info_hold(struct fib_info *fi) { - atomic_inc(&fi->fib_clntref); + refcount_inc(&fi->fib_clntref); } static inline void fib_info_put(struct fib_info *fi) { - if (atomic_dec_and_test(&fi->fib_clntref)) + if (refcount_dec_and_test(&fi->fib_clntref)) free_fib_info(fi); }
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 317026a..9c361bd 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c@@ -1174,7 +1174,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg) } fi->fib_treeref++; - atomic_inc(&fi->fib_clntref); + refcount_set(&fi->fib_clntref, 1); spin_lock_bh(&fib_info_lock); hlist_add_head(&fi->fib_hash, &fib_info_hash[fib_info_hashfn(fi)]);
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 2f0d823..d3bbe6e 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c@@ -1543,7 +1543,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, } if (!(fib_flags & FIB_LOOKUP_NOREF)) - atomic_inc(&fi->fib_clntref); + refcount_inc(&fi->fib_clntref); res->prefixlen = KEYLENGTH - fa->fa_slen; res->nh_sel = nhsel;
--
2.7.4