kernel/linux.git/include/net/sock.h, branch v6.6.27

tcp: properly terminate timers for kernel sockets

2024-04-10T14:35:42+00:00

[ Upstream commit 151c9c724d05d5b0dd8acd3e11cb69ef1f2dbada ] We had various syzbot reports about tcp timers firing after the corresponding netns has been dismantled. Fortunately Josef Bacik could trigger the issue more often, and could test a patch I wrote two years ago. When TCP sockets are closed, we call inet_csk_clear_xmit_timers() to 'stop' the timers. inet_csk_clear_xmit_timers() can be called from any context, including when socket lock is held. This is the reason it uses sk_stop_timer(), aka del_timer(). This means that ongoing timers might finish much later. For user sockets, this is fine because each running timer holds a reference on the socket, and the user socket holds a reference on the netns. For kernel sockets, we risk that the netns is freed before timer can complete, because kernel sockets do not hold reference on the netns. This patch adds inet_csk_clear_xmit_timers_sync() function that using sk_stop_timer_sync() to make sure all timers are terminated before the kernel socket is released. Modules using kernel sockets close them in their netns exit() handler. Also add sock_not_owned_by_me() helper to get LOCKDEP support : inet_csk_clear_xmit_timers_sync() must not be called while socket lock is held. It is very possible we can revert in the future commit 3a58f13a881e ("net: rds: acquire refcount on TCP sockets") which attempted to solve the issue in rds only. (net/smc/af_smc.c and net/mptcp/subflow.c have similar code) We probably can remove the check_net() tests from tcp_out_of_resources() and __tcp_close() in the future. Reported-by: Josef Bacik Closes: https://lore.kernel.org/netdev/20240314210740.GA2823176@perftesting/ Fixes: 26abe14379f8 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.") Fixes: 8a68173691f0 ("net: sk_clone_lock() should only do get_net() if the parent is not a kernel socket") Link: https://lore.kernel.org/bpf/CANn89i+484ffqb93aQm1N-tjxxvb3WDKX0EbD7318RwRgsatjw@mail.gmail.com/ Signed-off-by: Eric Dumazet Tested-by: Josef Bacik Cc: Tetsuo Handa Link: https://lore.kernel.org/r/20240322135732.1535772-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

udp: fix busy polling

2024-02-01T00:19:01+00:00

[ Upstream commit a54d51fb2dfb846aedf3751af501e9688db447f5 ] Generic sk_busy_loop_end() only looks at sk->sk_receive_queue for presence of packets. Problem is that for UDP sockets after blamed commit, some packets could be present in another queue: udp_sk(sk)->reader_queue In some cases, a busy poller could spin until timeout expiration, even if some packets are available in udp_sk(sk)->reader_queue. v3: - make sk_busy_loop_end() nicer (Willem) v2: - add a READ_ONCE(sk->sk_family) in sk_is_inet() to avoid KCSAN splats. - add a sk_is_inet() check in sk_is_udp() (Willem feedback) - add a sk_is_inet() check in sk_is_tcp(). Fixes: 2276f58ac589 ("udp: use a separate rx queue for packet reception") Signed-off-by: Eric Dumazet Reviewed-by: Paolo Abeni Reviewed-by: Willem de Bruijn Reviewed-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: constify sk_dst_get() and __sk_dst_get() argument

2024-01-10T16:17:00+00:00

[ Upstream commit 5033f58d5feed1040eebeadb0c5efc95b8bf5720 ] Both helpers only read fields from their socket argument. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

bpf: syzkaller found null ptr deref in unix_bpf proto add

2024-01-01T12:42:28+00:00

[ Upstream commit 8d6650646ce49e9a5b8c5c23eb94f74b1749f70f ] I added logic to track the sock pair for stream_unix sockets so that we ensure lifetime of the sock matches the time a sockmap could reference the sock (see fixes tag). I forgot though that we allow af_unix unconnected sockets into a sock{map|hash} map. This is problematic because previous fixed expected sk_pair() to exist and did not NULL check it. Because unconnected sockets have a NULL sk_pair this resulted in the NULL ptr dereference found by syzkaller. BUG: KASAN: null-ptr-deref in unix_stream_bpf_update_proto+0x72/0x430 net/unix/unix_bpf.c:171 Write of size 4 at addr 0000000000000080 by task syz-executor360/5073 Call Trace: ... sock_hold include/net/sock.h:777 [inline] unix_stream_bpf_update_proto+0x72/0x430 net/unix/unix_bpf.c:171 sock_map_init_proto net/core/sock_map.c:190 [inline] sock_map_link+0xb87/0x1100 net/core/sock_map.c:294 sock_map_update_common+0xf6/0x870 net/core/sock_map.c:483 sock_map_update_elem_sys+0x5b6/0x640 net/core/sock_map.c:577 bpf_map_update_value+0x3af/0x820 kernel/bpf/syscall.c:167 We considered just checking for the null ptr and skipping taking a ref on the NULL peer sock. But, if the socket is then connected() after being added to the sockmap we can cause the original issue again. So instead this patch blocks adding af_unix sockets that are not in the ESTABLISHED state. Reported-by: Eric Dumazet Reported-by: syzbot+e8030702aefd3444fb9e@syzkaller.appspotmail.com Fixes: 8866730aed51 ("bpf, sockmap: af_unix stream sockets need to hold ref for pair sock") Acked-by: Jakub Sitnicki Signed-off-by: John Fastabend Link: https://lore.kernel.org/r/20231201180139.328529-2-john.fastabend@gmail.com Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin

net: annotate data-races around sk->sk_dst_pending_confirm

2023-11-28T17:19:38+00:00

[ Upstream commit eb44ad4e635132754bfbcb18103f1dcb7058aedd ] This field can be read or written without socket lock being held. Add annotations to avoid load-store tearing. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: annotate data-races around sk->sk_tx_queue_mapping

2023-11-28T17:19:38+00:00

[ Upstream commit 0bb4d124d34044179b42a769a0c76f389ae973b6 ] This field can be read or written without socket lock being held. Add annotations to avoid load-store tearing. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

tcp: allow again tcp_disconnect() when threads are waiting

2023-10-13T23:49:32+00:00

As reported by Tom, .NET and applications build on top of it rely on connect(AF_UNSPEC) to async cancel pending I/O operations on TCP socket. The blamed commit below caused a regression, as such cancellation can now fail. As suggested by Eric, this change addresses the problem explicitly causing blocking I/O operation to terminate immediately (with an error) when a concurrent disconnect() is executed. Instead of tracking the number of threads blocked on a given socket, track the number of disconnect() issued on such socket. If such counter changes after a blocking operation releasing and re-acquiring the socket lock, error out the current operation. Fixes: 4faeee0cf8a5 ("tcp: deny tcp_disconnect() when threads are waiting") Reported-by: Tom Deseyn Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1886305 Suggested-by: Eric Dumazet Signed-off-by: Paolo Abeni Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/f3b95e47e3dbed840960548aebaa8d954372db41.1697008693.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski

net: annotate data-races around sk->sk_tsflags

2023-09-01T06:27:33+00:00

sk->sk_tsflags can be read locklessly, add corresponding annotations. Fixes: b9f40e21ef42 ("net-timestamp: move timestamp flags out of sk_flags") Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Signed-off-by: David S. Miller

net: annotate data-races around sk->sk_forward_alloc

2023-09-01T06:27:33+00:00

Every time sk->sk_forward_alloc is read locklessly, add a READ_ONCE(). Add sk_forward_alloc_add() helper to centralize updates, to reduce number of WRITE_ONCE(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2023-08-24T17:51:39+00:00

Cross-merge networking fixes after downstream PR. Conflicts: include/net/inet_sock.h f866fbc842de ("ipv4: fix data-races around inet->inet_id") c274af224269 ("inet: introduce inet->inet_flags") https://lore.kernel.org/all/679ddff6-db6e-4ff6-b177-574e90d0103d@tessares.net/ Adjacent changes: drivers/net/bonding/bond_alb.c e74216b8def3 ("bonding: fix macvlan over alb bond support") f11e5bd159b0 ("bonding: support balance-alb with openvswitch") drivers/net/ethernet/broadcom/bgmac.c d6499f0b7c7c ("net: bgmac: Return PTR_ERR() for fixed_phy_register()") 23a14488ea58 ("net: bgmac: Fix return value check for fixed_phy_register()") drivers/net/ethernet/broadcom/genet/bcmmii.c 32bbe64a1386 ("net: bcmgenet: Fix return value check for fixed_phy_register()") acf50d1adbf4 ("net: bcmgenet: Return PTR_ERR() for fixed_phy_register()") net/sctp/socket.c f866fbc842de ("ipv4: fix data-races around inet->inet_id") b09bde5c3554 ("inet: move inet->mc_loop to inet->inet_frags") Signed-off-by: Jakub Kicinski