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| author | Florian Westphal <fw@strlen.de> | 2020-11-19 16:34:54 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-11 13:25:04 +0100 |
| commit | 0fc22510ff5c8fb695781c7968b95da4a6110625 (patch) | |
| tree | c3b33bec4e37e7cc995fbfa57c8e66183a9a87bb | |
| parent | 5b27463cea05d69a56c26135558bdd57bcabbe52 (diff) | |
| download | linux-stable-0fc22510ff5c8fb695781c7968b95da4a6110625.tar.gz linux-stable-0fc22510ff5c8fb695781c7968b95da4a6110625.tar.bz2 linux-stable-0fc22510ff5c8fb695781c7968b95da4a6110625.zip | |
netfilter: nf_tables: avoid false-postive lockdep splat
commit c0700dfa2cae44c033ed97dade8a2679c7d22a9d upstream.
There are reports wrt lockdep splat in nftables, e.g.:
------------[ cut here ]------------
WARNING: CPU: 2 PID: 31416 at net/netfilter/nf_tables_api.c:622
lockdep_nfnl_nft_mutex_not_held+0x28/0x38 [nf_tables]
...
These are caused by an earlier, unrelated bug such as a n ABBA deadlock
in a different subsystem.
In such an event, lockdep is disabled and lockdep_is_held returns true
unconditionally. This then causes the WARN() in nf_tables.
Make the WARN conditional on lockdep still active to avoid this.
Fixes: f102d66b335a417 ("netfilter: nf_tables: use dedicated mutex to guard transactions")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lore.kernel.org/linux-kselftest/CA+G9fYvFUpODs+NkSYcnwKnXm62tmP=ksLeBPmB+KFrB2rvCtQ@mail.gmail.com/
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/netfilter/nf_tables_api.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 5b4632826dc6..9cc8e92f4b00 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -532,7 +532,8 @@ static void nft_request_module(struct net *net, const char *fmt, ...) static void lockdep_nfnl_nft_mutex_not_held(void) { #ifdef CONFIG_PROVE_LOCKING - WARN_ON_ONCE(lockdep_nfnl_is_held(NFNL_SUBSYS_NFTABLES)); + if (debug_locks) + WARN_ON_ONCE(lockdep_nfnl_is_held(NFNL_SUBSYS_NFTABLES)); #endif } |