6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
commit 031ae72825cef43e4650140b800ad58bf7a6a466 upstream.
syzbot found an use-after-free Read in ila_nf_input [1]
Issue here is that ila_xlat_exit_net() frees the rhashtable,
then call nf_unregister_net_hooks().
It should be done in the reverse way, with a synchronize_rcu().
This is a good match for a pre_exit() method.
[1]
BUG: KASAN: use-after-free in rht_key_hashfn include/linux/rhashtable.h:159 [inline]
BUG: KASAN: use-after-free in __rhashtable_lookup include/linux/rhashtable.h:604 [inline]
BUG: KASAN: use-after-free in rhashtable_lookup include/linux/rhashtable.h:646 [inline]
BUG: KASAN: use-after-free in rhashtable_lookup_fast+0x77a/0x9b0 include/linux/rhashtable.h:672
Read of size 4 at addr ffff888064620008 by task ksoftirqd/0/16
CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.11.0-rc4-syzkaller-00238-g2ad6d23f465a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
rht_key_hashfn include/linux/rhashtable.h:159 [inline]
__rhashtable_lookup include/linux/rhashtable.h:604 [inline]
rhashtable_lookup include/linux/rhashtable.h:646 [inline]
rhashtable_lookup_fast+0x77a/0x9b0 include/linux/rhashtable.h:672
ila_lookup_wildcards net/ipv6/ila/ila_xlat.c:132 [inline]
ila_xlat_addr net/ipv6/ila/ila_xlat.c:652 [inline]
ila_nf_input+0x1fe/0x3c0 net/ipv6/ila/ila_xlat.c:190
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626
nf_hook include/linux/netfilter.h:269 [inline]
NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312
__netif_receive_skb_one_core net/core/dev.c:5661 [inline]
__netif_receive_skb+0x1ea/0x650 net/core/dev.c:5775
process_backlog+0x662/0x15b0 net/core/dev.c:6108
__napi_poll+0xcb/0x490 net/core/dev.c:6772
napi_poll net/core/dev.c:6841 [inline]
net_rx_action+0x89b/0x1240 net/core/dev.c:6963
handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
run_ksoftirqd+0xca/0x130 kernel/softirq.c:928
smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x64620
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xbfffffff(buddy)
raw: 00fff00000000000 ffffea0000959608 ffffea00019d9408 0000000000000000
raw: 0000000000000000 0000000000000003 00000000bfffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52dc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_ZERO), pid 5242, tgid 5242 (syz-executor), ts 73611328570, free_ts 618981657187
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493
prep_new_page mm/page_alloc.c:1501 [inline]
get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3439
__alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4695
__alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
___kmalloc_large_node+0x8b/0x1d0 mm/slub.c:4103
__kmalloc_large_node_noprof+0x1a/0x80 mm/slub.c:4130
__do_kmalloc_node mm/slub.c:4146 [inline]
__kmalloc_node_noprof+0x2d2/0x440 mm/slub.c:4164
__kvmalloc_node_noprof+0x72/0x190 mm/util.c:650
bucket_table_alloc lib/rhashtable.c:186 [inline]
rhashtable_init_noprof+0x534/0xa60 lib/rhashtable.c:1071
ila_xlat_init_net+0xa0/0x110 net/ipv6/ila/ila_xlat.c:613
ops_init+0x359/0x610 net/core/net_namespace.c:139
setup_net+0x515/0xca0 net/core/net_namespace.c:343
copy_net_ns+0x4e2/0x7b0 net/core/net_namespace.c:508
create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
ksys_unshare+0x619/0xc10 kernel/fork.c:3328
__do_sys_unshare kernel/fork.c:3399 [inline]
__se_sys_unshare kernel/fork.c:3397 [inline]
__x64_sys_unshare+0x38/0x40 kernel/fork.c:3397
page last free pid 11846 tgid 11846 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1094 [inline]
free_unref_page+0xd22/0xea0 mm/page_alloc.c:2612
__folio_put+0x2c8/0x440 mm/swap.c:128
folio_put include/linux/mm.h:1486 [inline]
free_large_kmalloc+0x105/0x1c0 mm/slub.c:4565
kfree+0x1c4/0x360 mm/slub.c:4588
rhashtable_free_and_destroy+0x7c6/0x920 lib/rhashtable.c:1169
ila_xlat_exit_net+0x55/0x110 net/ipv6/ila/ila_xlat.c:626
ops_exit_list net/core/net_namespace.c:173 [inline]
cleanup_net+0x802/0xcc0 net/core/net_namespace.c:640
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Memory state around the buggy address:
ffff88806461ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88806461ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888064620000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888064620080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888064620100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
Fixes: 7f00feaf1076 ("ila: Add generic ILA translation facility")
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Tom Herbert <tom@xxxxxxxxxxxxxxx>
Reviewed-by: Florian Westphal <fw@xxxxxxxxx>
Link: https://patch.msgid.link/20240904144418.1162839-1-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/ila/ila.h | 1 +
net/ipv6/ila/ila_main.c | 6 ++++++
net/ipv6/ila/ila_xlat.c | 13 +++++++++----
3 files changed, 16 insertions(+), 4 deletions(-)
--- a/net/ipv6/ila/ila.h
+++ b/net/ipv6/ila/ila.h
@@ -108,6 +108,7 @@ int ila_lwt_init(void);
void ila_lwt_fini(void);
int ila_xlat_init_net(struct net *net);
+void ila_xlat_pre_exit_net(struct net *net);
void ila_xlat_exit_net(struct net *net);
int ila_xlat_nl_cmd_add_mapping(struct sk_buff *skb, struct genl_info *info);
--- a/net/ipv6/ila/ila_main.c
+++ b/net/ipv6/ila/ila_main.c
@@ -71,6 +71,11 @@ ila_xlat_init_fail:
return err;
}
+static __net_exit void ila_pre_exit_net(struct net *net)
+{
+ ila_xlat_pre_exit_net(net);
+}
+
static __net_exit void ila_exit_net(struct net *net)
{
ila_xlat_exit_net(net);
@@ -78,6 +83,7 @@ static __net_exit void ila_exit_net(stru
static struct pernet_operations ila_net_ops = {
.init = ila_init_net,
+ .pre_exit = ila_pre_exit_net,
.exit = ila_exit_net,
.id = &ila_net_id,
.size = sizeof(struct ila_net),
--- a/net/ipv6/ila/ila_xlat.c
+++ b/net/ipv6/ila/ila_xlat.c
@@ -619,6 +619,15 @@ int ila_xlat_init_net(struct net *net)
return 0;
}
+void ila_xlat_pre_exit_net(struct net *net)
+{
+ struct ila_net *ilan = net_generic(net, ila_net_id);
+
+ if (ilan->xlat.hooks_registered)
+ nf_unregister_net_hooks(net, ila_nf_hook_ops,
+ ARRAY_SIZE(ila_nf_hook_ops));
+}
+
void ila_xlat_exit_net(struct net *net)
{
struct ila_net *ilan = net_generic(net, ila_net_id);
@@ -626,10 +635,6 @@ void ila_xlat_exit_net(struct net *net)
rhashtable_free_and_destroy(&ilan->xlat.rhash_table, ila_free_cb, NULL);
free_bucket_spinlocks(ilan->xlat.locks);
-
- if (ilan->xlat.hooks_registered)
- nf_unregister_net_hooks(net, ila_nf_hook_ops,
- ARRAY_SIZE(ila_nf_hook_ops));
}
static int ila_xlat_addr(struct sk_buff *skb, bool sir2ila)
