diff options
| author | Santosh Nayak <santoshprasadnayak@gmail.com> | 2012-03-06 05:22:50 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-03-06 23:43:49 +0400 |
| commit | 848edc69192a38bf9d261032f248b14f47e6af8b (patch) | |
| tree | 799712600cd661118131c8dfa79a231e21293531 | |
| parent | 2a15cd2ff488a9fdb55e5e34060f499853b27c77 (diff) | |
| download | linux-848edc69192a38bf9d261032f248b14f47e6af8b.tar.xz | |
netfilter: ebtables: fix wrong name length while copying to user-space
user-space ebtables expects 32 bytes-long names, but xt_match names
use 29 bytes. We have to copy less 29 bytes and then, make sure we
fill the remaining bytes with zeroes.
Signed-off-by: Santosh Nayak <santoshprasadnayak@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/bridge/netfilter/ebtables.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 8aa4ad0e06af..15e9575f7207 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -1335,7 +1335,12 @@ static inline int ebt_make_matchname(const struct ebt_entry_match *m, const char *base, char __user *ubase) { char __user *hlp = ubase + ((char *)m - base); - if (copy_to_user(hlp, m->u.match->name, EBT_FUNCTION_MAXNAMELEN)) + char name[EBT_FUNCTION_MAXNAMELEN] = {}; + + /* ebtables expects 32 bytes long names but xt_match names are 29 bytes + long. Copy 29 bytes and fill remaining bytes with zeroes. */ + strncpy(name, m->u.match->name, sizeof(name)); + if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN)) return -EFAULT; return 0; } @@ -1344,7 +1349,10 @@ static inline int ebt_make_watchername(const struct ebt_entry_watcher *w, const char *base, char __user *ubase) { char __user *hlp = ubase + ((char *)w - base); - if (copy_to_user(hlp , w->u.watcher->name, EBT_FUNCTION_MAXNAMELEN)) + char name[EBT_FUNCTION_MAXNAMELEN] = {}; + + strncpy(name, w->u.watcher->name, sizeof(name)); + if (copy_to_user(hlp , name, EBT_FUNCTION_MAXNAMELEN)) return -EFAULT; return 0; } @@ -1355,10 +1363,12 @@ ebt_make_names(struct ebt_entry *e, const char *base, char __user *ubase) int ret; char __user *hlp; const struct ebt_entry_target *t; + char name[EBT_FUNCTION_MAXNAMELEN] = {}; if (e->bitmask == 0) return 0; + strncpy(name, t->u.target->name, sizeof(name)); hlp = ubase + (((char *)e + e->target_offset) - base); t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); @@ -1368,7 +1378,7 @@ ebt_make_names(struct ebt_entry *e, const char *base, char __user *ubase) ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase); if (ret != 0) return ret; - if (copy_to_user(hlp, t->u.target->name, EBT_FUNCTION_MAXNAMELEN)) + if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN)) return -EFAULT; return 0; } |