diff options
| author | Eric Dumazet <edumazet@google.com> | 2026-08-27 09:59:36 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-08-28 15:35:38 -0700 |
| commit | 18666c73afe95eeca8707c699b63f96ce3acda42 (patch) | |
| tree | ccd71ba57e251398162fabca41643e3029fc825d /include/net | |
| parent | c185c78e2a0eed9bbc63537b99f65a8d5da8112d (diff) | |
tcp: use GFP_ATOMIC in tcp_send_active_reset()
tcp_send_active_reset() can be called from contexts where gfp_any()
(in tcp_disconnect()) or sk->sk_allocation (in __tcp_close() and
mptcp_do_fastclose()) evaluates to GFP_KERNEL, which includes
__GFP_FS and __GFP_DIRECT_RECLAIM.
Allocating with GFP_KERNEL while holding the socket lock (sk_lock) creates
a lockdep dependency:
sk_lock -> fs_reclaim
This causes false-positive lockdep circular locking warnings with storage
subsystems (such as nvme-tcp) that acquire socket locks in block I/O paths
and invoke tcp_disconnect() or close sockets upon teardown:
set->srcu -> sk_lock -> fs_reclaim -> elevator_lock -> set->srcu
Active resets are small RST packet headers that should never
enter direct reclaim or block while holding socket locks.
Use sk_gfp_mask(sk, GFP_ATOMIC | __GFP_NOWARN) inside tcp_send_active_reset()
and remove its priority argument. This preserves __GFP_MEMALLOC access
for SOCK_MEMALLOC sockets, suppresses allocation failure warnings,
and aligns with other control packet allocations (e.g. tcp_send_fin(),
__tcp_send_ack(), tcp_xmit_probe_skb()).
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260827095936.551524-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/tcp.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index 670c20876f26..436495ff2271 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -765,8 +765,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue, void tcp_send_probe0(struct sock *); int tcp_write_wakeup(struct sock *, int mib); void tcp_send_fin(struct sock *sk); -void tcp_send_active_reset(struct sock *sk, gfp_t priority, - enum sk_rst_reason reason); +void tcp_send_active_reset(struct sock *sk, enum sk_rst_reason reason); int tcp_send_synack(struct sock *); void tcp_push_one(struct sock *, unsigned int mss_now); void __tcp_send_ack(struct sock *sk, u32 rcv_nxt, u16 flags); |