[PATCH 5.15 020/128] netfilter: nf_tables: fix use-after-free in nft_set_catchall_destroy()

Greg Kroah-Hartman
2021-12-27T15:46:41Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 0f7d9b31ce7abdbb29bf018131ac920c9f698518 ]

We need to use list_for_each_entry_safe() iterator
because we can not access @catchall after kfree_rcu() call.

syzbot reported:

BUG: KASAN: use-after-free in nft_set_catchall_destroy net/netfilter/nf_tables_api.c:4486 [inline]
BUG: KASAN: use-after-free in nft_set_destroy net/netfilter/nf_tables_api.c:4504 [inline]
BUG: KASAN: use-after-free in nft_set_destroy+0x3fd/0x4f0 net/netfilter/nf_tables_api.c:4493
Read of size 8 at addr ffff8880716e5b80 by task syz-executor.3/8871

CPU: 1 PID: 8871 Comm: syz-executor.3 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x8d/0x2ed mm/kasan/report.c:247
__kasan_report mm/kasan/report.c:433 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
nft_set_catchall_destroy net/netfilter/nf_tables_api.c:4486 [inline]
nft_set_destroy net/netfilter/nf_tables_api.c:4504 [inline]
nft_set_destroy+0x3fd/0x4f0 net/netfilter/nf_tables_api.c:4493
__nft_release_table+0x79f/0xcd0 net/netfilter/nf_tables_api.c:9626
nft_rcv_nl_event+0x4f8/0x670 net/netfilter/nf_tables_api.c:9688
notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
blocking_notifier_call_chain kernel/notifier.c:318 [inline]
blocking_notifier_call_chain+0x67/0x90 kernel/notifier.c:306
netlink_release+0xcb6/0x1dd0 net/netlink/af_netlink.c:788
__sock_release+0xcd/0x280 net/socket.c:649
sock_close+0x18/0x20 net/socket.c:1314
__fput+0x286/0x9f0 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f75fbf28adb
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007ffd8da7ec10 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f75fbf28adb
RDX: 00007f75fc08e828 RSI: ffffffffffffffff RDI: 0000000000000003
RBP: 00007f75fc08a960 R08: 0000000000000000 R09: 00007f75fc08e830
R10: 00007ffd8da7ed10 R11: 0000000000000293 R12: 00000000002067c3
R13: 00007ffd8da7ed10 R14: 00007f75fc088f60 R15: 0000000000000032
</TASK>

Allocated by task 8886:
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
____kasan_kmalloc mm/kasan/common.c:472 [inline]
__kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:522
kasan_kmalloc include/linux/kasan.h:269 [inline]
kmem_cache_alloc_trace+0x1ea/0x4a0 mm/slab.c:3575
kmalloc include/linux/slab.h:590 [inline]
nft_setelem_catchall_insert net/netfilter/nf_tables_api.c:5544 [inline]
nft_setelem_insert net/netfilter/nf_tables_api.c:5562 [inline]
nft_add_set_elem+0x232e/0x2f40 net/netfilter/nf_tables_api.c:5936
nf_tables_newsetelem+0x6ff/0xbb0 net/netfilter/nf_tables_api.c:6032
nfnetlink_rcv_batch+0x1710/0x25f0 net/netfilter/nfnetlink.c:513
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline]
nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:652
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x904/0xdf0 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:724
____sys_sendmsg+0x6e8/0x810 net/socket.c:2409
___sys_sendmsg+0xf3/0x170 net/socket.c:2463
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2492
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 15335:
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
kasan_set_track+0x21/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xd1/0x110 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:235 [inline]
__cache_free mm/slab.c:3445 [inline]
kmem_cache_free_bulk+0x67/0x1e0 mm/slab.c:3766
kfree_bulk include/linux/slab.h:446 [inline]
kfree_rcu_work+0x51c/0xa10 kernel/rcu/tree.c:3273
process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Last potentially related work creation:
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
__kasan_record_aux_stack+0xb5/0xe0 mm/kasan/generic.c:348
kvfree_call_rcu+0x74/0x990 kernel/rcu/tree.c:3550
nft_set_catchall_destroy net/netfilter/nf_tables_api.c:4489 [inline]
nft_set_destroy net/netfilter/nf_tables_api.c:4504 [inline]
nft_set_destroy+0x34a/0x4f0 net/netfilter/nf_tables_api.c:4493
__nft_release_table+0x79f/0xcd0 net/netfilter/nf_tables_api.c:9626
nft_rcv_nl_event+0x4f8/0x670 net/netfilter/nf_tables_api.c:9688
notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
blocking_notifier_call_chain kernel/notifier.c:318 [inline]
blocking_notifier_call_chain+0x67/0x90 kernel/notifier.c:306
netlink_release+0xcb6/0x1dd0 net/netlink/af_netlink.c:788
__sock_release+0xcd/0x280 net/socket.c:649
sock_close+0x18/0x20 net/socket.c:1314
__fput+0x286/0x9f0 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff8880716e5b80
which belongs to the cache kmalloc-64 of size 64
The buggy address is located 0 bytes inside of
64-byte region [ffff8880716e5b80, ffff8880716e5bc0)
The buggy address belongs to the page:
page:ffffea0001c5b940 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880716e5c00 pfn:0x716e5
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0000911848 ffffea00007c4d48 ffff888010c40200
raw: ffff8880716e5c00 ffff8880716e5000 000000010000001e 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x242040(__GFP_IO|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 3638, ts 211086074437, free_ts 211031029429
prep_new_page mm/page_alloc.c:2418 [inline]
get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369
__alloc_pages_node include/linux/gfp.h:570 [inline]
kmem_getpages mm/slab.c:1377 [inline]
cache_grow_begin+0x75/0x470 mm/slab.c:2593
cache_alloc_refill+0x27f/0x380 mm/slab.c:2965
____cache_alloc mm/slab.c:3048 [inline]
____cache_alloc mm/slab.c:3031 [inline]
__do_cache_alloc mm/slab.c:3275 [inline]
slab_alloc mm/slab.c:3316 [inline]
__do_kmalloc mm/slab.c:3700 [inline]
__kmalloc+0x3b3/0x4d0 mm/slab.c:3711
kmalloc include/linux/slab.h:595 [inline]
kzalloc include/linux/slab.h:724 [inline]
tomoyo_get_name+0x234/0x480 security/tomoyo/memory.c:173
tomoyo_parse_name_union+0xbc/0x160 security/tomoyo/util.c:260
tomoyo_update_path_number_acl security/tomoyo/file.c:687 [inline]
tomoyo_write_file+0x629/0x7f0 security/tomoyo/file.c:1034
tomoyo_write_domain2+0x116/0x1d0 security/tomoyo/common.c:1152
tomoyo_add_entry security/tomoyo/common.c:2042 [inline]
tomoyo_supervisor+0xbc7/0xf00 security/tomoyo/common.c:2103
tomoyo_audit_path_number_log security/tomoyo/file.c:235 [inline]
tomoyo_path_number_perm+0x419/0x590 security/tomoyo/file.c:734
security_file_ioctl+0x50/0xb0 security/security.c:1541
__do_sys_ioctl fs/ioctl.c:868 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0xb3/0x200 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1338 [inline]
free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389
free_unref_page_prepare mm/page_alloc.c:3309 [inline]
free_unref_page+0x19/0x690 mm/page_alloc.c:3388
slab_destroy mm/slab.c:1627 [inline]
slabs_destroy+0x89/0xc0 mm/slab.c:1647
cache_flusharray mm/slab.c:3418 [inline]
___cache_free+0x4cc/0x610 mm/slab.c:3480
qlink_free mm/kasan/quarantine.c:146 [inline]
qlist_free_all+0x4e/0x110 mm/kasan/quarantine.c:165
kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
__kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:444
kasan_slab_alloc include/linux/kasan.h:259 [inline]
slab_post_alloc_hook mm/slab.h:519 [inline]
slab_alloc_node mm/slab.c:3261 [inline]
kmem_cache_alloc_node+0x2ea/0x590 mm/slab.c:3599
__alloc_skb+0x215/0x340 net/core/skbuff.c:414
alloc_skb include/linux/skbuff.h:1126 [inline]
nlmsg_new include/net/netlink.h:953 [inline]
rtmsg_ifinfo_build_skb+0x72/0x1a0 net/core/rtnetlink.c:3808
rtmsg_ifinfo_event net/core/rtnetlink.c:3844 [inline]
rtmsg_ifinfo_event net/core/rtnetlink.c:3835 [inline]
rtmsg_ifinfo+0x83/0x120 net/core/rtnetlink.c:3853
netdev_state_change net/core/dev.c:1395 [inline]
netdev_state_change+0x114/0x130 net/core/dev.c:1386
linkwatch_do_dev+0x10e/0x150 net/core/link_watch.c:167
__linkwatch_run_queue+0x233/0x6a0 net/core/link_watch.c:213
linkwatch_event+0x4a/0x60 net/core/link_watch.c:252
process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298

Memory state around the buggy address:
ffff8880716e5a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff8880716e5b00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
>ffff8880716e5b80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff8880716e5c00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff8880716e5c80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc

Fixes: aaa31047a6d2 ("netfilter: nftables: add catch-all set element support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nf_tables_api.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index c0851fec11d46..c207728226372 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4481,9 +4481,9 @@ struct nft_set_elem_catchall {
static void nft_set_catchall_destroy(const struct nft_ctx *ctx,
struct nft_set *set)
{
- struct nft_set_elem_catchall *catchall;
+ struct nft_set_elem_catchall *next, *catchall;

- list_for_each_entry_rcu(catchall, &set->catchall_list, list) {
+ list_for_each_entry_safe(catchall, next, &set->catchall_list, list) {
list_del_rcu(&catchall->list);
nft_set_elem_destroy(set, catchall->elem, true);
kfree_rcu(catchall);
--
2.34.1