The value in idx and the number of rules handled in that particular
__nf_tables_dump_rules() call is not identical. The former is a cursor
to pick up from if multiple netlink messages are needed, so its value is
ever increasing. Fixing this is not just a matter of subtracting s_idx
from it, though: When resetting rules in multiple chains,
__nf_tables_dump_rules() is called for each and cb->args[0] is not
adjusted in between. Introduce a dedicated counter to record the number
of rules reset in this call in a less confusing way.
While being at it, prevent the direct return upon buffer exhaustion: Any
rules previously dumped into that skb would evade audit logging
otherwise.
Fixes: 9b5ba5c9c5109 ("netfilter: nf_tables: Unbreak audit log reset")
Signed-off-by: Phil Sutter <phil@xxxxxx>
---
Changes since v2:
- Restore per-chain logging as requested.
Changes since v1:
- Use max_t() to eliminate the kernel warning
---
net/netfilter/nf_tables_api.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index e429ebba74b3d..446e1882428e6 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3449,6 +3449,8 @@ static int __nf_tables_dump_rules(struct sk_buff *skb,
struct net *net = sock_net(skb->sk);
const struct nft_rule *rule, *prule;
unsigned int s_idx = cb->args[0];
+ unsigned int entries = 0;
+ int ret = 0;
u64 handle;
prule = NULL;
@@ -3471,9 +3473,11 @@ static int __nf_tables_dump_rules(struct sk_buff *skb,
NFT_MSG_NEWRULE,
NLM_F_MULTI | NLM_F_APPEND,
table->family,
- table, chain, rule, handle, reset) < 0)
- return 1;
-
+ table, chain, rule, handle, reset) < 0) {
+ ret = 1;
+ break;
+ }
+ entries++;
nl_dump_check_consistent(cb, nlmsg_hdr(skb));
cont:
prule = rule;
@@ -3481,10 +3485,10 @@ static int __nf_tables_dump_rules(struct sk_buff *skb,
(*idx)++;
}
- if (reset && *idx)
- audit_log_rule_reset(table, cb->seq, *idx);
+ if (reset && entries)
+ audit_log_rule_reset(table, cb->seq, entries);
- return 0;
+ return ret;
}
static int nf_tables_dump_rules(struct sk_buff *skb,
--
2.41.0
