| Message ID | fe340d0aaea857d7401b537f1e43e534b69470a2.1732875656.git.pabeni@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] ipmr: tune the ipmr_can_free_table() checks. | expand |
On 11/29/24 3:23 AM, Paolo Abeni wrote: > diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c > index c5b8ec5c0a8c..d814a352cc05 100644 > --- a/net/ipv4/ipmr.c > +++ b/net/ipv4/ipmr.c > @@ -122,7 +122,7 @@ static void ipmr_expire_process(struct timer_list *t); > > static bool ipmr_can_free_table(struct net *net) > { > - return !check_net(net) || !net->ipv4.mr_rules_ops; > + return !check_net(net) || !net->list.next; > } > > static struct mr_table *ipmr_mr_table_iter(struct net *net, > diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c > index 7f1902ac3586..37224a5f1bbe 100644 > --- a/net/ipv6/ip6mr.c > +++ b/net/ipv6/ip6mr.c > @@ -110,7 +110,7 @@ static void ipmr_expire_process(struct timer_list *t); > > static bool ip6mr_can_free_table(struct net *net) > { > - return !check_net(net) || !net->ipv6.mr6_rules_ops; > + return !check_net(net) || !net->list.next; > } > > static struct mr_table *ip6mr_mr_table_iter(struct net *net, this exposes internal namespace details to ipmr code. How about a helper in net_namespace.h that indicates the intent here?
On 11/29/24 18:01, David Ahern wrote: > On 11/29/24 3:23 AM, Paolo Abeni wrote: >> diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c >> index c5b8ec5c0a8c..d814a352cc05 100644 >> --- a/net/ipv4/ipmr.c >> +++ b/net/ipv4/ipmr.c >> @@ -122,7 +122,7 @@ static void ipmr_expire_process(struct timer_list *t); >> >> static bool ipmr_can_free_table(struct net *net) >> { >> - return !check_net(net) || !net->ipv4.mr_rules_ops; >> + return !check_net(net) || !net->list.next; >> } >> >> static struct mr_table *ipmr_mr_table_iter(struct net *net, >> diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c >> index 7f1902ac3586..37224a5f1bbe 100644 >> --- a/net/ipv6/ip6mr.c >> +++ b/net/ipv6/ip6mr.c >> @@ -110,7 +110,7 @@ static void ipmr_expire_process(struct timer_list *t); >> >> static bool ip6mr_can_free_table(struct net *net) >> { >> - return !check_net(net) || !net->ipv6.mr6_rules_ops; >> + return !check_net(net) || !net->list.next; >> } >> >> static struct mr_table *ip6mr_mr_table_iter(struct net *net, > > this exposes internal namespace details to ipmr code. How about a helper > in net_namespace.h that indicates the intent here? Makes sense. What about something alike: static bool net_setup_completed(struct net *net) { return net->list.next; } in net_namespace.h? The question is mainly about the name, which I'm notably bad to pick. Thanks, Paolo
On 11/29/24 18:13, Paolo Abeni wrote: > On 11/29/24 18:01, David Ahern wrote: >> On 11/29/24 3:23 AM, Paolo Abeni wrote: >>> diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c >>> index c5b8ec5c0a8c..d814a352cc05 100644 >>> --- a/net/ipv4/ipmr.c >>> +++ b/net/ipv4/ipmr.c >>> @@ -122,7 +122,7 @@ static void ipmr_expire_process(struct timer_list *t); >>> >>> static bool ipmr_can_free_table(struct net *net) >>> { >>> - return !check_net(net) || !net->ipv4.mr_rules_ops; >>> + return !check_net(net) || !net->list.next; >>> } >>> >>> static struct mr_table *ipmr_mr_table_iter(struct net *net, >>> diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c >>> index 7f1902ac3586..37224a5f1bbe 100644 >>> --- a/net/ipv6/ip6mr.c >>> +++ b/net/ipv6/ip6mr.c >>> @@ -110,7 +110,7 @@ static void ipmr_expire_process(struct timer_list *t); >>> >>> static bool ip6mr_can_free_table(struct net *net) >>> { >>> - return !check_net(net) || !net->ipv6.mr6_rules_ops; >>> + return !check_net(net) || !net->list.next; >>> } >>> >>> static struct mr_table *ip6mr_mr_table_iter(struct net *net, >> >> this exposes internal namespace details to ipmr code. How about a helper >> in net_namespace.h that indicates the intent here? > > Makes sense. What about something alike: > > static bool net_setup_completed(struct net *net) > { > return net->list.next; > } > > in net_namespace.h? > > The question is mainly about the name, which I'm notably bad to pick. Thinking again about it, I would use 'net_initialized', unless someone has a better option. Thanks, Paolo
On 11/29/24 11:02 AM, Paolo Abeni wrote: > Thinking again about it, I would use 'net_initialized', unless someone > has a better option. works for me.
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index c5b8ec5c0a8c..d814a352cc05 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -122,7 +122,7 @@ static void ipmr_expire_process(struct timer_list *t); static bool ipmr_can_free_table(struct net *net) { - return !check_net(net) || !net->ipv4.mr_rules_ops; + return !check_net(net) || !net->list.next; } static struct mr_table *ipmr_mr_table_iter(struct net *net, diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 7f1902ac3586..37224a5f1bbe 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -110,7 +110,7 @@ static void ipmr_expire_process(struct timer_list *t); static bool ip6mr_can_free_table(struct net *net) { - return !check_net(net) || !net->ipv6.mr6_rules_ops; + return !check_net(net) || !net->list.next; } static struct mr_table *ip6mr_mr_table_iter(struct net *net,
Eric reported a syzkaller-triggered splat caused by recent ipmr changes: WARNING: CPU: 2 PID: 6041 at net/ipv6/ip6mr.c:419 ip6mr_free_table+0xbd/0x120 net/ipv6/ip6mr.c:419 Modules linked in: CPU: 2 UID: 0 PID: 6041 Comm: syz-executor183 Not tainted 6.12.0-syzkaller-10681-g65ae975e97d5 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:ip6mr_free_table+0xbd/0x120 net/ipv6/ip6mr.c:419 Code: 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 58 49 83 bc 24 c0 0e 00 00 00 74 09 e8 44 ef a9 f7 90 <0f> 0b 90 e8 3b ef a9 f7 48 8d 7b 38 e8 12 a3 96 f7 48 89 df be 0f RSP: 0018:ffffc90004267bd8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88803c710000 RCX: ffffffff89e4d844 RDX: ffff88803c52c880 RSI: ffffffff89e4d87c RDI: ffff88803c578ec0 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88803c578000 R13: ffff88803c710000 R14: ffff88803c710008 R15: dead000000000100 FS: 00007f7a855ee6c0(0000) GS:ffff88806a800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7a85689938 CR3: 000000003c492000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ip6mr_rules_exit+0x176/0x2d0 net/ipv6/ip6mr.c:283 ip6mr_net_exit_batch+0x53/0xa0 net/ipv6/ip6mr.c:1388 ops_exit_list+0x128/0x180 net/core/net_namespace.c:177 setup_net+0x4fe/0x860 net/core/net_namespace.c:394 copy_net_ns+0x2b4/0x6b0 net/core/net_namespace.c:500 create_new_namespaces+0x3ea/0xad0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228 ksys_unshare+0x45d/0xa40 kernel/fork.c:3334 __do_sys_unshare kernel/fork.c:3405 [inline] __se_sys_unshare kernel/fork.c:3403 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3403 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7a856332d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7a855ee238 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f7a856bd308 RCX: 00007f7a856332d9 RDX: 00007f7a8560f8c6 RSI: 0000000000000000 RDI: 0000000062040200 RBP: 00007f7a856bd300 R08: 00007fff932160a7 R09: 00007f7a855ee6c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a856bd30c R13: 0000000000000000 R14: 00007fff93215fc0 R15: 00007fff932160a8 </TASK> The root cause is a network namespace creation failing after successful initialization of the ipmr subsystem. Such a case is not currently matched by the ipmr_can_free_table() helper. New namespaces are zeroed on allocation and inserted into net ns list only after successful creation; when deleting an ipmr table, the list next pointer can be NULL only on netns initialization failure. Update the ipmr_can_free_table() checks leveraging such condition. Reported-by: Eric Dumazet <edumazet@google.com> Fixes: 11b6e701bce9 ("ipmr: add debug check for mr table cleanup") Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- net/ipv4/ipmr.c | 2 +- net/ipv6/ip6mr.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)