From: Daniel Borkmann daniel@iogearbox.net
[ Upstream commit 8c5c2a4898e3d6bad86e29d471e023c8a19ba799 ]
syzbot reported a splat and bisected it to recent commit ed17aa92dc56 ("bpf, sockmap: fix deadlocks in the sockhash and sockmap"):
[...] WARNING: CPU: 1 PID: 9280 at kernel/softirq.c:376 __local_bh_enable_ip+0xbe/0x130 kernel/softirq.c:376 Modules linked in: CPU: 1 PID: 9280 Comm: syz-executor.1 Not tainted 6.2.0-syzkaller-13249-gd319f344561d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 RIP: 0010:__local_bh_enable_ip+0xbe/0x130 kernel/softirq.c:376 [...] Call Trace: <TASK> spin_unlock_bh include/linux/spinlock.h:395 [inline] sock_map_del_link+0x2ea/0x510 net/core/sock_map.c:165 sock_map_unref+0xb0/0x1d0 net/core/sock_map.c:184 sock_hash_delete_elem+0x1ec/0x2a0 net/core/sock_map.c:945 map_delete_elem kernel/bpf/syscall.c:1536 [inline] __sys_bpf+0x2edc/0x53e0 kernel/bpf/syscall.c:5053 __do_sys_bpf kernel/bpf/syscall.c:5166 [inline] __se_sys_bpf kernel/bpf/syscall.c:5164 [inline] __x64_sys_bpf+0x79/0xc0 kernel/bpf/syscall.c:5164 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fe8f7c8c169 </TASK> [...]
Revert for now until we have a proper solution.
Fixes: ed17aa92dc56 ("bpf, sockmap: fix deadlocks in the sockhash and sockmap") Reported-by: syzbot+49f6cef45247ff249498@syzkaller.appspotmail.com Cc: Hsin-Wei Hung hsinweih@uci.edu Cc: Xin Liu liuxin350@huawei.com Cc: John Fastabend john.fastabend@gmail.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Link: https://lore.kernel.org/bpf/000000000000f1db9605f939720e@google.com/ Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/sock_map.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 2408965e5c7b6..a68a7290a3b2b 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -414,9 +414,8 @@ static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test, { struct sock *sk; int err = 0; - unsigned long flags;
- raw_spin_lock_irqsave(&stab->lock, flags); + raw_spin_lock_bh(&stab->lock); sk = *psk; if (!sk_test || sk_test == sk) sk = xchg(psk, NULL); @@ -426,7 +425,7 @@ static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test, else err = -EINVAL;
- raw_spin_unlock_irqrestore(&stab->lock, flags); + raw_spin_unlock_bh(&stab->lock); return err; }
@@ -924,12 +923,11 @@ static int sock_hash_delete_elem(struct bpf_map *map, void *key) struct bpf_shtab_bucket *bucket; struct bpf_shtab_elem *elem; int ret = -ENOENT; - unsigned long flags;
hash = sock_hash_bucket_hash(key, key_size); bucket = sock_hash_select_bucket(htab, hash);
- raw_spin_lock_irqsave(&bucket->lock, flags); + raw_spin_lock_bh(&bucket->lock); elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); if (elem) { hlist_del_rcu(&elem->node); @@ -937,7 +935,7 @@ static int sock_hash_delete_elem(struct bpf_map *map, void *key) sock_hash_free_elem(htab, elem); ret = 0; } - raw_spin_unlock_irqrestore(&bucket->lock, flags); + raw_spin_unlock_bh(&bucket->lock); return ret; }