[PATCH v5 net 0/2] tcp/rds: Fix use-after-free around kernel TCP reqsk.

[PATCH v5 net 0/2] tcp/rds: Fix use-after-free around kernel TCP reqsk.

[Kuniyuki Iwashima]

syzkaller reported an warning of netns ref tracker for RDS TCP listener,
which commit 740ea3c4a0b2 ("tcp: Clean up kernel listener's reqsk in
inet_twsk_purge()") fixed for per-netns ehash.

This series fixes the bug in the partial fix and fixes the reported bug
in the global ehash.


Changes:
  v5:
    * Reuse the correct logic for reqsk in inet_twsk_purge().

  v4: https://lore.kernel.org/netdev/20240307232151.55963-1-kuniyu@amazon.com/
    * Add sk_family/refcnt check in inet_twsk_purge().

  v3: https://lore.kernel.org/netdev/20240307224423.53315-1-kuniyu@amazon.com/
    * Drop patch 2, 3, 5
    * Fix uaf by iterating ehash and purging reqsk during netns dismantle.

  v2: https://lore.kernel.org/netdev/20240227011041.97375-1-kuniyu@amazon.com/
    * Add patch 1, 3, 5
    * Use __sock_create() instead of converting socket
    * Drop Sowmini from CC as it's bounced (patchwork may complain)

  v1: https://lore.kernel.org/netdev/20240223172448.94084-1-kuniyu@amazon.com/


Eric Dumazet (1):
  tcp: Fix NEW_SYN_RECV handling in inet_twsk_purge()

Kuniyuki Iwashima (1):
  rds: tcp: Fix use-after-free of net in reqsk_timer_handler().

 net/ipv4/inet_timewait_sock.c | 41 ++++++++++++++++-------------------
 net/ipv4/tcp_minisocks.c      |  4 ----
 2 files changed, 19 insertions(+), 26 deletions(-)

-- 
2.30.2

[PATCH v5 net 1/2] tcp: Fix NEW_SYN_RECV handling in inet_twsk_purge()

[Kuniyuki Iwashima]

From: Eric Dumazet <edumazet@google.com>

inet_twsk_purge() uses rcu to find TIME_WAIT and NEW_SYN_RECV
objects to purge.

These objects use SLAB_TYPESAFE_BY_RCU semantic and need special
care. We need to use refcount_inc_not_zero(&sk->sk_refcnt).

Reuse the existing correct logic I wrote for TIME_WAIT,
because both structures have common locations for
sk_state, sk_family, and netns pointer.

If after the refcount_inc_not_zero() the object fields longer match
the keys, use sock_gen_put(sk) to release the refcount.

Then we can call inet_twsk_deschedule_put() for TIME_WAIT,
inet_csk_reqsk_queue_drop_and_put() for NEW_SYN_RECV sockets,
with BH disabled.

Then we need to restart the loop because we had drop rcu_read_lock().

Fixes: 740ea3c4a0b2 ("tcp: Clean up kernel listener's reqsk in inet_twsk_purge()")
Link: https://lore.kernel.org/netdev/CANn89iLvFuuihCtt9PME2uS1WJATnf5fKjDToa1WzVnRzHnPfg@mail.gmail.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
[ Kuniyuki: fixed some checkpatch checks & warnings. ]
---
 net/ipv4/inet_timewait_sock.c | 41 ++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 22 deletions(-)

diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index 5befa4de5b24..e8de45d34d56 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -263,12 +263,12 @@ void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo, bool rearm)
 }
 EXPORT_SYMBOL_GPL(__inet_twsk_schedule);
 
+/* Remove all non full sockets (TIME_WAIT and NEW_SYN_RECV) for dead netns */
 void inet_twsk_purge(struct inet_hashinfo *hashinfo, int family)
 {
-	struct inet_timewait_sock *tw;
-	struct sock *sk;
 	struct hlist_nulls_node *node;
 	unsigned int slot;
+	struct sock *sk;
 
 	for (slot = 0; slot <= hashinfo->ehash_mask; slot++) {
 		struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
@@ -277,38 +277,35 @@ void inet_twsk_purge(struct inet_hashinfo *hashinfo, int family)
 		rcu_read_lock();
 restart:
 		sk_nulls_for_each_rcu(sk, node, &head->chain) {
-			if (sk->sk_state != TCP_TIME_WAIT) {
-				/* A kernel listener socket might not hold refcnt for net,
-				 * so reqsk_timer_handler() could be fired after net is
-				 * freed.  Userspace listener and reqsk never exist here.
-				 */
-				if (unlikely(sk->sk_state == TCP_NEW_SYN_RECV &&
-					     hashinfo->pernet)) {
-					struct request_sock *req = inet_reqsk(sk);
-
-					inet_csk_reqsk_queue_drop_and_put(req->rsk_listener, req);
-				}
+			int state = inet_sk_state_load(sk);
 
+			if ((1 << state) & ~(TCPF_TIME_WAIT |
+					     TCPF_NEW_SYN_RECV))
 				continue;
-			}
 
-			tw = inet_twsk(sk);
-			if ((tw->tw_family != family) ||
-				refcount_read(&twsk_net(tw)->ns.count))
+			if (sk->sk_family != family ||
+			    refcount_read(&sock_net(sk)->ns.count))
 				continue;
 
-			if (unlikely(!refcount_inc_not_zero(&tw->tw_refcnt)))
+			if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
 				continue;
 
-			if (unlikely((tw->tw_family != family) ||
-				     refcount_read(&twsk_net(tw)->ns.count))) {
-				inet_twsk_put(tw);
+			if (unlikely(sk->sk_family != family ||
+				     refcount_read(&sock_net(sk)->ns.count))) {
+				sock_gen_put(sk);
 				goto restart;
 			}
 
 			rcu_read_unlock();
 			local_bh_disable();
-			inet_twsk_deschedule_put(tw);
+			if (state == TCP_TIME_WAIT) {
+				inet_twsk_deschedule_put(inet_twsk(sk));
+			} else {
+				struct request_sock *req = inet_reqsk(sk);
+
+				inet_csk_reqsk_queue_drop_and_put(req->rsk_listener,
+								  req);
+			}
 			local_bh_enable();
 			goto restart_rcu;
 		}
-- 
2.30.2

[PATCH v5 net 2/2] rds: tcp: Fix use-after-free of net in reqsk_timer_handler().

[Kuniyuki Iwashima]

syzkaller reported a warning of netns tracker [0] followed by KASAN
splat [1] and another ref tracker warning [1].

syzkaller could not find a repro, but in the log, the only suspicious
sequence was as follows:

  18:26:22 executing program 1:
  r0 = socket$inet6_mptcp(0xa, 0x1, 0x106)
  ...
  connect$inet6(r0, &(0x7f0000000080)={0xa, 0x4001, 0x0, @loopback}, 0x1c) (async)

The notable thing here is 0x4001 in connect(), which is RDS_TCP_PORT.

So, the scenario would be:

  1. unshare(CLONE_NEWNET) creates a per netns tcp listener in
      rds_tcp_listen_init().
  2. syz-executor connect()s to it and creates a reqsk.
  3. syz-executor exit()s immediately.
  4. netns is dismantled.  [0]
  5. reqsk timer is fired, and UAF happens while freeing reqsk.  [1]
  6. listener is freed after RCU grace period.  [2]

Basically, reqsk assumes that the listener guarantees netns safety
until all reqsk timers are expired by holding the listener's refcount.
However, this was not the case for kernel sockets.

Commit 740ea3c4a0b2 ("tcp: Clean up kernel listener's reqsk in
inet_twsk_purge()") fixed this issue only for per-netns ehash.

Let's apply the same fix for the global ehash.

[0]:
ref_tracker: net notrefcnt@0000000065449cc3 has 1/1 users at
     sk_alloc (./include/net/net_namespace.h:337 net/core/sock.c:2146)
     inet6_create (net/ipv6/af_inet6.c:192 net/ipv6/af_inet6.c:119)
     __sock_create (net/socket.c:1572)
     rds_tcp_listen_init (net/rds/tcp_listen.c:279)
     rds_tcp_init_net (net/rds/tcp.c:577)
     ops_init (net/core/net_namespace.c:137)
     setup_net (net/core/net_namespace.c:340)
     copy_net_ns (net/core/net_namespace.c:497)
     create_new_namespaces (kernel/nsproxy.c:110)
     unshare_nsproxy_namespaces (kernel/nsproxy.c:228 (discriminator 4))
     ksys_unshare (kernel/fork.c:3429)
     __x64_sys_unshare (kernel/fork.c:3496)
     do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
     entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)
...
WARNING: CPU: 0 PID: 27 at lib/ref_tracker.c:179 ref_tracker_dir_exit (lib/ref_tracker.c:179)

[1]:
BUG: KASAN: slab-use-after-free in inet_csk_reqsk_queue_drop (./include/net/inet_hashtables.h:180 net/ipv4/inet_connection_sock.c:952 net/ipv4/inet_connection_sock.c:966)
Read of size 8 at addr ffff88801b370400 by task swapper/0/0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Call Trace:
 <IRQ>
 dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1))
 print_report (mm/kasan/report.c:378 mm/kasan/report.c:488)
 kasan_report (mm/kasan/report.c:603)
 inet_csk_reqsk_queue_drop (./include/net/inet_hashtables.h:180 net/ipv4/inet_connection_sock.c:952 net/ipv4/inet_connection_sock.c:966)
 reqsk_timer_handler (net/ipv4/inet_connection_sock.c:979 net/ipv4/inet_connection_sock.c:1092)
 call_timer_fn (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/timer.h:127 kernel/time/timer.c:1701)
 __run_timers.part.0 (kernel/time/timer.c:1752 kernel/time/timer.c:2038)
 run_timer_softirq (kernel/time/timer.c:2053)
 __do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:554)
 irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632 kernel/softirq.c:644)
 sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1076 (discriminator 14))
 </IRQ>

Allocated by task 258 on cpu 0 at 83.612050s:
 kasan_save_stack (mm/kasan/common.c:48)
 kasan_save_track (mm/kasan/common.c:68)
 __kasan_slab_alloc (mm/kasan/common.c:343)
 kmem_cache_alloc (mm/slub.c:3813 mm/slub.c:3860 mm/slub.c:3867)
 copy_net_ns (./include/linux/slab.h:701 net/core/net_namespace.c:421 net/core/net_namespace.c:480)
 create_new_namespaces (kernel/nsproxy.c:110)
 unshare_nsproxy_namespaces (kernel/nsproxy.c:228 (discriminator 4))
 ksys_unshare (kernel/fork.c:3429)
 __x64_sys_unshare (kernel/fork.c:3496)
 do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)

Freed by task 27 on cpu 0 at 329.158864s:
 kasan_save_stack (mm/kasan/common.c:48)
 kasan_save_track (mm/kasan/common.c:68)
 kasan_save_free_info (mm/kasan/generic.c:643)
 __kasan_slab_free (mm/kasan/common.c:265)
 kmem_cache_free (mm/slub.c:4299 mm/slub.c:4363)
 cleanup_net (net/core/net_namespace.c:456 net/core/net_namespace.c:446 net/core/net_namespace.c:639)
 process_one_work (kernel/workqueue.c:2638)
 worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787)
 kthread (kernel/kthread.c:388)
 ret_from_fork (arch/x86/kernel/process.c:153)
 ret_from_fork_asm (arch/x86/entry/entry_64.S:250)

The buggy address belongs to the object at ffff88801b370000
 which belongs to the cache net_namespace of size 4352
The buggy address is located 1024 bytes inside of
 freed 4352-byte region [ffff88801b370000, ffff88801b371100)

[2]:
WARNING: CPU: 0 PID: 95 at lib/ref_tracker.c:228 ref_tracker_free (lib/ref_tracker.c:228 (discriminator 1))
Modules linked in:
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:ref_tracker_free (lib/ref_tracker.c:228 (discriminator 1))
...
Call Trace:
<IRQ>
 __sk_destruct (./include/net/net_namespace.h:353 net/core/sock.c:2204)
 rcu_core (./arch/x86/include/asm/preempt.h:26 kernel/rcu/tree.c:2165 kernel/rcu/tree.c:2433)
 __do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:554)
 irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632 kernel/softirq.c:644)
 sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1076 (discriminator 14))
</IRQ>

Reported-by: syzkaller <syzkaller@googlegroups.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Fixes: 467fa15356ac ("RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 net/ipv4/tcp_minisocks.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 9e85f2a0bddd..0ecc7311dc6c 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -398,10 +398,6 @@ void tcp_twsk_purge(struct list_head *net_exit_list, int family)
 			/* Even if tw_refcount == 1, we must clean up kernel reqsk */
 			inet_twsk_purge(net->ipv4.tcp_death_row.hashinfo, family);
 		} else if (!purged_once) {
-			/* The last refcount is decremented in tcp_sk_exit_batch() */
-			if (refcount_read(&net->ipv4.tcp_death_row.tw_refcount) == 1)
-				continue;
-
 			inet_twsk_purge(&tcp_hashinfo, family);
 			purged_once = true;
 		}
-- 
2.30.2

Re: [PATCH v5 net 2/2] rds: tcp: Fix use-after-free of net in reqsk_timer_handler().

[Paolo Abeni]

On Fri, 2024-03-08 at 12:01 -0800, Kuniyuki Iwashima wrote:
> syzkaller reported a warning of netns tracker [0] followed by KASAN
> splat [1] and another ref tracker warning [1].
> 
> syzkaller could not find a repro, but in the log, the only suspicious
> sequence was as follows:
> 
>   18:26:22 executing program 1:
>   r0 = socket$inet6_mptcp(0xa, 0x1, 0x106)
>   ...
>   connect$inet6(r0, &(0x7f0000000080)={0xa, 0x4001, 0x0, @loopback}, 0x1c) (async)
> 
> The notable thing here is 0x4001 in connect(), which is RDS_TCP_PORT.
> 
> So, the scenario would be:
> 
>   1. unshare(CLONE_NEWNET) creates a per netns tcp listener in
>       rds_tcp_listen_init().
>   2. syz-executor connect()s to it and creates a reqsk.
>   3. syz-executor exit()s immediately.
>   4. netns is dismantled.  [0]
>   5. reqsk timer is fired, and UAF happens while freeing reqsk.  [1]
>   6. listener is freed after RCU grace period.  [2]
> 
> Basically, reqsk assumes that the listener guarantees netns safety
> until all reqsk timers are expired by holding the listener's refcount.
> However, this was not the case for kernel sockets.
> 
> Commit 740ea3c4a0b2 ("tcp: Clean up kernel listener's reqsk in
> inet_twsk_purge()") fixed this issue only for per-netns ehash.
> 
> Let's apply the same fix for the global ehash.
> 
> [0]:
> ref_tracker: net notrefcnt@0000000065449cc3 has 1/1 users at
>      sk_alloc (./include/net/net_namespace.h:337 net/core/sock.c:2146)
>      inet6_create (net/ipv6/af_inet6.c:192 net/ipv6/af_inet6.c:119)
>      __sock_create (net/socket.c:1572)
>      rds_tcp_listen_init (net/rds/tcp_listen.c:279)
>      rds_tcp_init_net (net/rds/tcp.c:577)
>      ops_init (net/core/net_namespace.c:137)
>      setup_net (net/core/net_namespace.c:340)
>      copy_net_ns (net/core/net_namespace.c:497)
>      create_new_namespaces (kernel/nsproxy.c:110)
>      unshare_nsproxy_namespaces (kernel/nsproxy.c:228 (discriminator 4))
>      ksys_unshare (kernel/fork.c:3429)
>      __x64_sys_unshare (kernel/fork.c:3496)
>      do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
>      entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)
> ...
> WARNING: CPU: 0 PID: 27 at lib/ref_tracker.c:179 ref_tracker_dir_exit (lib/ref_tracker.c:179)
> 
> [1]:
> BUG: KASAN: slab-use-after-free in inet_csk_reqsk_queue_drop (./include/net/inet_hashtables.h:180 net/ipv4/inet_connection_sock.c:952 net/ipv4/inet_connection_sock.c:966)
> Read of size 8 at addr ffff88801b370400 by task swapper/0/0
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
> Call Trace:
>  <IRQ>
>  dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1))
>  print_report (mm/kasan/report.c:378 mm/kasan/report.c:488)
>  kasan_report (mm/kasan/report.c:603)
>  inet_csk_reqsk_queue_drop (./include/net/inet_hashtables.h:180 net/ipv4/inet_connection_sock.c:952 net/ipv4/inet_connection_sock.c:966)
>  reqsk_timer_handler (net/ipv4/inet_connection_sock.c:979 net/ipv4/inet_connection_sock.c:1092)
>  call_timer_fn (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/timer.h:127 kernel/time/timer.c:1701)
>  __run_timers.part.0 (kernel/time/timer.c:1752 kernel/time/timer.c:2038)
>  run_timer_softirq (kernel/time/timer.c:2053)
>  __do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:554)
>  irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632 kernel/softirq.c:644)
>  sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1076 (discriminator 14))
>  </IRQ>
> 
> Allocated by task 258 on cpu 0 at 83.612050s:
>  kasan_save_stack (mm/kasan/common.c:48)
>  kasan_save_track (mm/kasan/common.c:68)
>  __kasan_slab_alloc (mm/kasan/common.c:343)
>  kmem_cache_alloc (mm/slub.c:3813 mm/slub.c:3860 mm/slub.c:3867)
>  copy_net_ns (./include/linux/slab.h:701 net/core/net_namespace.c:421 net/core/net_namespace.c:480)
>  create_new_namespaces (kernel/nsproxy.c:110)
>  unshare_nsproxy_namespaces (kernel/nsproxy.c:228 (discriminator 4))
>  ksys_unshare (kernel/fork.c:3429)
>  __x64_sys_unshare (kernel/fork.c:3496)
>  do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
>  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)
> 
> Freed by task 27 on cpu 0 at 329.158864s:
>  kasan_save_stack (mm/kasan/common.c:48)
>  kasan_save_track (mm/kasan/common.c:68)
>  kasan_save_free_info (mm/kasan/generic.c:643)
>  __kasan_slab_free (mm/kasan/common.c:265)
>  kmem_cache_free (mm/slub.c:4299 mm/slub.c:4363)
>  cleanup_net (net/core/net_namespace.c:456 net/core/net_namespace.c:446 net/core/net_namespace.c:639)
>  process_one_work (kernel/workqueue.c:2638)
>  worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787)
>  kthread (kernel/kthread.c:388)
>  ret_from_fork (arch/x86/kernel/process.c:153)
>  ret_from_fork_asm (arch/x86/entry/entry_64.S:250)
> 
> The buggy address belongs to the object at ffff88801b370000
>  which belongs to the cache net_namespace of size 4352
> The buggy address is located 1024 bytes inside of
>  freed 4352-byte region [ffff88801b370000, ffff88801b371100)
> 
> [2]:
> WARNING: CPU: 0 PID: 95 at lib/ref_tracker.c:228 ref_tracker_free (lib/ref_tracker.c:228 (discriminator 1))
> Modules linked in:
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
> RIP: 0010:ref_tracker_free (lib/ref_tracker.c:228 (discriminator 1))
> ...
> Call Trace:
> <IRQ>
>  __sk_destruct (./include/net/net_namespace.h:353 net/core/sock.c:2204)
>  rcu_core (./arch/x86/include/asm/preempt.h:26 kernel/rcu/tree.c:2165 kernel/rcu/tree.c:2433)
>  __do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:554)
>  irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632 kernel/softirq.c:644)
>  sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1076 (discriminator 14))
> </IRQ>
> 
> Reported-by: syzkaller <syzkaller@googlegroups.com>
> Suggested-by: Eric Dumazet <edumazet@google.com>
> Fixes: 467fa15356ac ("RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.")
> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>

Eric, the patches LGTM, and I can see your suggested-by tag, but better
safe then sorry: could you please confirm it is ok for you too?

Thanks,

Paolo

Re: [PATCH v5 net 2/2] rds: tcp: Fix use-after-free of net in reqsk_timer_handler().

[Eric Dumazet]

On Tue, Mar 12, 2024 at 12:04 PM Paolo Abeni <pabeni@redhat.com> wrote:
>
> On Fri, 2024-03-08 at 12:01 -0800, Kuniyuki Iwashima wrote:
> > syzkaller reported a warning of netns tracker [0] followed by KASAN
> > splat [1] and another ref tracker warning [1].
> >
> > syzkaller could not find a repro, but in the log, the only suspicious
> > sequence was as follows:
> >
> >   18:26:22 executing program 1:
> >   r0 = socket$inet6_mptcp(0xa, 0x1, 0x106)
> >   ...
> >   connect$inet6(r0, &(0x7f0000000080)={0xa, 0x4001, 0x0, @loopback}, 0x1c) (async)
> >
> > The notable thing here is 0x4001 in connect(), which is RDS_TCP_PORT.
> >

>
> Eric, the patches LGTM, and I can see your suggested-by tag, but better
> safe then sorry: could you please confirm it is ok for you too?

Sure thing.

Reviewed-by: Eric Dumazet <edumazet@google.com>

Thanks !

Re: [PATCH v5 net 0/2] tcp/rds: Fix use-after-free around kernel TCP reqsk.

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Fri, 8 Mar 2024 12:01:20 -0800 you wrote:
> syzkaller reported an warning of netns ref tracker for RDS TCP listener,
> which commit 740ea3c4a0b2 ("tcp: Clean up kernel listener's reqsk in
> inet_twsk_purge()") fixed for per-netns ehash.
> 
> This series fixes the bug in the partial fix and fixes the reported bug
> in the global ehash.
> 
> [...]

Here is the summary with links:
  - [v5,net,1/2] tcp: Fix NEW_SYN_RECV handling in inet_twsk_purge()
    https://git.kernel.org/netdev/net/c/a7b7079bc292
  - [v5,net,2/2] rds: tcp: Fix use-after-free of net in reqsk_timer_handler().
    https://git.kernel.org/netdev/net/c/a28895fc04fa

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [PATCH v5 net 0/2] tcp/rds: Fix use-after-free around kernel TCP reqsk.

[Jakub Kicinski]

On Tue, 12 Mar 2024 15:10:32 +0000 patchwork-bot+netdevbpf@kernel.org
wrote:
>   - [v5,net,1/2] tcp: Fix NEW_SYN_RECV handling in inet_twsk_purge()
>     https://git.kernel.org/netdev/net/c/a7b7079bc292
>   - [v5,net,2/2] rds: tcp: Fix use-after-free of net in reqsk_timer_handler().
>     https://git.kernel.org/netdev/net/c/a28895fc04fa

I think I need to discard these, otherwise I won't be able to fast
forward after Linus pulls :( I re-apply later.

Re: [PATCH v5 net 0/2] tcp/rds: Fix use-after-free around kernel TCP reqsk.

[Jakub Kicinski]

On Tue, 12 Mar 2024 08:59:42 -0700 Jakub Kicinski wrote:
> On Tue, 12 Mar 2024 15:10:32 +0000 patchwork-bot+netdevbpf@kernel.org
> wrote:
> >   - [v5,net,1/2] tcp: Fix NEW_SYN_RECV handling in inet_twsk_purge()
> >     https://git.kernel.org/netdev/net/c/a7b7079bc292
> >   - [v5,net,2/2] rds: tcp: Fix use-after-free of net in reqsk_timer_handler().
> >     https://git.kernel.org/netdev/net/c/a28895fc04fa  
> 
> I think I need to discard these, otherwise I won't be able to fast
> forward after Linus pulls :( I re-apply later.

Back in it goes, hopefully we didn't cause too much strife with 
the reset.