[syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    1c5fc27bc48a Merge tag 'nf-next-24-06-28' of git://git.ker..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=103b1da9980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5264b58fdff6e881
dashboard link: https://syzkaller.appspot.com/bug?extid=4fd66a69358fc15ae2ad
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=148791c6980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12cecb1e980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9672225af907/disk-1c5fc27b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0f14d163a914/vmlinux-1c5fc27b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ec6c331e6a6e/bzImage-1c5fc27b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4fd66a69358fc15ae2ad@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in nft_ctx_update include/net/netfilter/nf_tables.h:1831 [inline]
BUG: KASAN: slab-use-after-free in nft_commit_release net/netfilter/nf_tables_api.c:9530 [inline]
BUG: KASAN: slab-use-after-free in nf_tables_trans_destroy_work+0x152b/0x1750 net/netfilter/nf_tables_api.c:9597
Read of size 2 at addr ffff88802b0051c4 by task kworker/1:1/45

CPU: 1 PID: 45 Comm: kworker/1:1 Not tainted 6.10.0-rc5-syzkaller-01137-g1c5fc27bc48a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: events nf_tables_trans_destroy_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 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
 nft_ctx_update include/net/netfilter/nf_tables.h:1831 [inline]
 nft_commit_release net/netfilter/nf_tables_api.c:9530 [inline]
 nf_tables_trans_destroy_work+0x152b/0x1750 net/netfilter/nf_tables_api.c:9597
 process_one_work kernel/workqueue.c:3248 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3329
 worker_thread+0x86d/0xd50 kernel/workqueue.c:3409
 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>

Allocated by task 6682:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 kmalloc_trace_noprof+0x19c/0x2c0 mm/slub.c:4154
 kmalloc_noprof include/linux/slab.h:660 [inline]
 kzalloc_noprof include/linux/slab.h:778 [inline]
 nf_tables_newtable+0x52e/0x1dc0 net/netfilter/nf_tables_api.c:1465
 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:522 [inline]
 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:644 [inline]
 nfnetlink_rcv+0x1427/0x2a90 net/netfilter/nfnetlink.c:662
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x7f0/0x990 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585
 ___sys_sendmsg net/socket.c:2639 [inline]
 __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6682:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2196 [inline]
 slab_free mm/slub.c:4438 [inline]
 kfree+0x149/0x360 mm/slub.c:4559
 nf_tables_table_destroy net/netfilter/nf_tables_api.c:1672 [inline]
 __nft_release_table+0xe80/0xf40 net/netfilter/nf_tables_api.c:11517
 nft_rcv_nl_event+0x55f/0x6d0 net/netfilter/nf_tables_api.c:11576
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 blocking_notifier_call_chain+0x69/0x90 kernel/notifier.c:388
 netlink_release+0x11a6/0x1b10 net/netlink/af_netlink.c:787
 __sock_release net/socket.c:659 [inline]
 sock_close+0xbc/0x240 net/socket.c:1421
 __fput+0x406/0x8b0 fs/file_table.c:422
 task_work_run+0x24f/0x310 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa27/0x27e0 kernel/exit.c:874
 do_group_exit+0x207/0x2c0 kernel/exit.c:1023
 __do_sys_exit_group kernel/exit.c:1034 [inline]
 __se_sys_exit_group kernel/exit.c:1032 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1032
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 insert_work+0x3e/0x330 kernel/workqueue.c:2208
 __queue_work+0xc16/0xee0 kernel/workqueue.c:2360
 queue_work_on+0x1c2/0x380 kernel/workqueue.c:2411
 queue_work include/linux/workqueue.h:621 [inline]
 schedule_work include/linux/workqueue.h:682 [inline]
 __rhashtable_remove_fast_one include/linux/rhashtable.h:1069 [inline]
 __rhashtable_remove_fast include/linux/rhashtable.h:1093 [inline]
 rhltable_remove+0x1097/0x1160 include/linux/rhashtable.h:1144
 nft_chain_del net/netfilter/nf_tables_api.c:9781 [inline]
 __nft_release_table+0xc57/0xf40 net/netfilter/nf_tables_api.c:11513
 nft_rcv_nl_event+0x55f/0x6d0 net/netfilter/nf_tables_api.c:11576
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 blocking_notifier_call_chain+0x69/0x90 kernel/notifier.c:388
 netlink_release+0x11a6/0x1b10 net/netlink/af_netlink.c:787
 __sock_release net/socket.c:659 [inline]
 sock_close+0xbc/0x240 net/socket.c:1421
 __fput+0x406/0x8b0 fs/file_table.c:422
 task_work_run+0x24f/0x310 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa27/0x27e0 kernel/exit.c:874
 do_group_exit+0x207/0x2c0 kernel/exit.c:1023
 __do_sys_exit_group kernel/exit.c:1034 [inline]
 __se_sys_exit_group kernel/exit.c:1032 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1032
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802b005000
 which belongs to the cache kmalloc-cg-512 of size 512
The buggy address is located 452 bytes inside of
 freed 512-byte region [ffff88802b005000, ffff88802b005200)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b004
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffefff(slab)
raw: 00fff00000000040 ffff88801504f140 ffffea0000b63700 0000000000000002
raw: 0000000000000000 0000000080100010 00000001ffffefff 0000000000000000
head: 00fff00000000040 ffff88801504f140 ffffea0000b63700 0000000000000002
head: 0000000000000000 0000000080100010 00000001ffffefff 0000000000000000
head: 00fff00000000002 ffffea0000ac0101 ffffffffffffffff 0000000000000000
head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4764, tgid 4764 (dhcpcd), ts 34584428687, free_ts 34557820760
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1473
 prep_new_page mm/page_alloc.c:1481 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3425
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4683
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x5f/0x120 mm/slub.c:2265
 allocate_slab+0x5a/0x2f0 mm/slub.c:2428
 new_slab mm/slub.c:2481 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3667
 __slab_alloc+0x58/0xa0 mm/slub.c:3757
 __slab_alloc_node mm/slub.c:3810 [inline]
 slab_alloc_node mm/slub.c:3990 [inline]
 __do_kmalloc_node mm/slub.c:4122 [inline]
 kmalloc_node_track_caller_noprof+0x281/0x440 mm/slub.c:4143
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:605
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:674
 alloc_skb include/linux/skbuff.h:1320 [inline]
 alloc_skb_with_frags+0xc3/0x770 net/core/skbuff.c:6524
 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2815
 unix_dgram_sendmsg+0x6d3/0x1f80 net/unix/af_unix.c:2030
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 __sys_sendto+0x3a4/0x4f0 net/socket.c:2192
 __do_sys_sendto net/socket.c:2204 [inline]
 __se_sys_sendto net/socket.c:2200 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2200
page last free pid 4764 tgid 4764 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1093 [inline]
 free_unref_page+0xd22/0xea0 mm/page_alloc.c:2588
 stack_depot_save_flags+0x6f6/0x830 lib/stackdepot.c:666
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_save_track+0x51/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3940 [inline]
 slab_alloc_node mm/slub.c:4002 [inline]
 kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4045
 kmalloc_reserve+0xa8/0x2a0 net/core/skbuff.c:583
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:674
 alloc_skb include/linux/skbuff.h:1320 [inline]
 __ip6_append_data+0x2ba6/0x4070 net/ipv6/ip6_output.c:1648
 ip6_append_data+0x264/0x3a0 net/ipv6/ip6_output.c:1835
 rawv6_sendmsg+0x18f1/0x23c0 net/ipv6/raw.c:919
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585
 ___sys_sendmsg net/socket.c:2639 [inline]
 __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88802b005080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802b005100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802b005180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88802b005200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802b005280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
This report is generated by a bot. It may contain errors.
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[Hillf Danton]

On Mon, 01 Jul 2024 13:19:15 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    1c5fc27bc48a Merge tag 'nf-next-24-06-28' of git://git.ker..
> git tree:       net-next
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12cecb1e980000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git  1c5fc27bc48a

--- x/include/net/netfilter/nf_tables.h
+++ y/include/net/netfilter/nf_tables.h
@@ -1281,6 +1281,7 @@ struct nft_table {
 	u64				hgenerator;
 	u64				handle;
 	u32				use;
+	atomic_t			cnt;
 	u16				family:6,
 					flags:8,
 					genmask:2;
--- x/net/netfilter/nf_tables_api.c
+++ y/net/netfilter/nf_tables_api.c
@@ -162,6 +162,8 @@ static struct nft_trans *nft_trans_alloc
 
 	trans->net = ctx->net;
 	trans->table = ctx->table;
+	if (trans->table)
+		atomic_inc(&trans->table->cnt);
 	trans->seq = ctx->seq;
 	trans->flags = ctx->flags;
 	trans->report = ctx->report;
@@ -1498,6 +1500,7 @@ static int nf_tables_newtable(struct sk_
 	if (err < 0)
 		goto err_trans;
 
+	atomic_inc(&table->cnt);
 	list_add_tail_rcu(&table->list, &nft_net->tables);
 	return 0;
 err_trans:
@@ -1663,6 +1666,8 @@ static int nf_tables_deltable(struct sk_
 
 static void nf_tables_table_destroy(struct nft_table *table)
 {
+	if (!atomic_dec_and_test(&table->cnt))
+		return;
 	if (WARN_ON(table->use > 0))
 		return;
 
@@ -9532,7 +9537,6 @@ static void nft_commit_release(struct nf
 	switch (trans->msg_type) {
 	case NFT_MSG_DELTABLE:
 	case NFT_MSG_DESTROYTABLE:
-		nf_tables_table_destroy(trans->table);
 		break;
 	case NFT_MSG_NEWCHAIN:
 		free_percpu(nft_trans_chain_stats(trans));
@@ -9572,6 +9576,9 @@ static void nft_commit_release(struct nf
 		break;
 	}
 
+	if (trans->table)
+		nf_tables_table_destroy(trans->table);
+
 	if (trans->put_net)
 		put_net(trans->net);
 
--

Re: [syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[Edward Adam Davis]

Unbalanced increase and decrease of use in the table

#syz test: net-next 1c5fc27bc48a

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 70d0bad029fd..b77b764955a0 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1498,6 +1498,7 @@ static int nf_tables_newtable(struct sk_buff *skb, const struct nfnl_info *info,
 	if (err < 0)
 		goto err_trans;
 
+	nft_use_inc_restore(&table->use);
 	list_add_tail_rcu(&table->list, &nft_net->tables);
 	return 0;
 err_trans:

Re: [syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+4fd66a69358fc15ae2ad@syzkaller.appspotmail.com

Tested on:

commit:         f2a491c9 netfilter: nf_tables: unconditionally flush p..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/fwestphal/nf-next.git flush_uncond
console output: https://syzkaller.appspot.com/x/log.txt?x=1626b9c6980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e78fc116033e0ab7
dashboard link: https://syzkaller.appspot.com/bug?extid=4fd66a69358fc15ae2ad
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.

Re: [syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+4fd66a69358fc15ae2ad@syzkaller.appspotmail.com

Tested on:

commit:         1c5fc27b Merge tag 'nf-next-24-06-28' of git://git.ker..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=10e91b25980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5264b58fdff6e881
dashboard link: https://syzkaller.appspot.com/bug?extid=4fd66a69358fc15ae2ad
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=104f8466980000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in __nft_release_table

------------[ cut here ]------------
WARNING: CPU: 1 PID: 5870 at net/netfilter/nf_tables_api.c:1667 nf_tables_table_destroy net/netfilter/nf_tables_api.c:1667 [inline]
WARNING: CPU: 1 PID: 5870 at net/netfilter/nf_tables_api.c:1667 __nft_release_table+0xed3/0xf40 net/netfilter/nf_tables_api.c:11518
Modules linked in:
CPU: 1 PID: 5870 Comm: syz.3.18 Not tainted 6.10.0-rc5-syzkaller-01137-g1c5fc27bc48a-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:nf_tables_table_destroy net/netfilter/nf_tables_api.c:1667 [inline]
RIP: 0010:__nft_release_table+0xed3/0xf40 net/netfilter/nf_tables_api.c:11518
Code: 8b 04 25 28 00 00 00 48 3b 84 24 e0 00 00 00 75 72 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 6e f3 e0 f7 90 <0f> 0b 90 eb a8 89 d9 80 e1 07 fe c1 38 c1 0f 8c fd f1 ff ff 48 89
RSP: 0018:ffffc900045e78a0 EFLAGS: 00010293
RAX: ffffffff89b53392 RBX: 0000000000000001 RCX: ffff88802a273c00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900045e79d0 R08: ffffffff89b532c3 R09: 1ffffffff25f78ca
R10: dffffc0000000000 R11: fffffbfff25f78cb R12: dffffc0000000000
R13: ffff88801ee19100 R14: ffff88801181e970 R15: ffff88801181e9c0
FS:  00005555817aa500(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000200 CR3: 000000001c2b0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 nft_rcv_nl_event+0x55f/0x6d0 net/netfilter/nf_tables_api.c:11577
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 blocking_notifier_call_chain+0x69/0x90 kernel/notifier.c:388
 netlink_release+0x11a6/0x1b10 net/netlink/af_netlink.c:787
 __sock_release net/socket.c:659 [inline]
 sock_close+0xbc/0x240 net/socket.c:1421
 __fput+0x406/0x8b0 fs/file_table.c:422
 task_work_run+0x24f/0x310 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f91b1775b99
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff8ddfaf58 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000019328 RCX: 00007f91b1775b99
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: ffffffffffffffff R08: 0000000000000001 R09: 000000048ddfb26f
R10: 00007f91b1600000 R11: 0000000000000246 R12: 00007f91b1903fac
R13: 0000000000000032 R14: 00007f91b1905aa0 R15: 00007f91b1903fa0
 </TASK>


Tested on:

commit:         1c5fc27b Merge tag 'nf-next-24-06-28' of git://git.ker..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=107e8ec6980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5264b58fdff6e881
dashboard link: https://syzkaller.appspot.com/bug?extid=4fd66a69358fc15ae2ad
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=137e0f1e980000

Re: [syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[Edward Adam Davis]

Unbalanced increase and decrease of use in the table

#syz test: net-next 1c5fc27bc48a

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 70d0bad029fd..33139e1b6d46 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1498,6 +1498,7 @@ static int nf_tables_newtable(struct sk_buff *skb, const struct nfnl_info *info,
 	if (err < 0)
 		goto err_trans;
 
+	nft_use_inc_restore(&table->use);
 	list_add_tail_rcu(&table->list, &nft_net->tables);
 	return 0;
 err_trans:
@@ -9529,6 +9530,9 @@ static void nft_commit_release(struct nft_trans *trans)
 
 	nft_ctx_update(&ctx, trans);
 
+	if (trans->table)
+		nft_use_dec(&trans->table->use);
+
 	switch (trans->msg_type) {
 	case NFT_MSG_DELTABLE:
 	case NFT_MSG_DESTROYTABLE:

Re: [syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in __nft_release_table

------------[ cut here ]------------
WARNING: CPU: 1 PID: 5991 at net/netfilter/nf_tables_api.c:1667 nf_tables_table_destroy net/netfilter/nf_tables_api.c:1667 [inline]
WARNING: CPU: 1 PID: 5991 at net/netfilter/nf_tables_api.c:1667 __nft_release_table+0xed3/0xf40 net/netfilter/nf_tables_api.c:11521
Modules linked in:
CPU: 1 PID: 5991 Comm: syz.1.21 Not tainted 6.10.0-rc5-syzkaller-01137-g1c5fc27bc48a-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:nf_tables_table_destroy net/netfilter/nf_tables_api.c:1667 [inline]
RIP: 0010:__nft_release_table+0xed3/0xf40 net/netfilter/nf_tables_api.c:11521
Code: 8b 04 25 28 00 00 00 48 3b 84 24 e0 00 00 00 75 72 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 9e f2 e0 f7 90 <0f> 0b 90 eb a8 89 d9 80 e1 07 fe c1 38 c1 0f 8c fd f1 ff ff 48 89
RSP: 0018:ffffc9000465f8a0 EFLAGS: 00010293
RAX: ffffffff89b53462 RBX: 0000000000000001 RCX: ffff8880258d8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000465f9d0 R08: ffffffff89b53393 R09: 1ffffffff25f78ca
R10: dffffc0000000000 R11: fffffbfff25f78cb R12: dffffc0000000000
R13: ffff88802be8fb00 R14: ffff8880644edd70 R15: ffff8880644eddc0
FS:  000055556d3a6500(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6829251378 CR3: 000000002a83e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 nft_rcv_nl_event+0x55f/0x6d0 net/netfilter/nf_tables_api.c:11580
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 blocking_notifier_call_chain+0x69/0x90 kernel/notifier.c:388
 netlink_release+0x11a6/0x1b10 net/netlink/af_netlink.c:787
 __sock_release net/socket.c:659 [inline]
 sock_close+0xbc/0x240 net/socket.c:1421
 __fput+0x406/0x8b0 fs/file_table.c:422
 task_work_run+0x24f/0x310 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f052bf75b99
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd273700b8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000018813 RCX: 00007f052bf75b99
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: ffffffffffffffff R08: 0000000000000001 R09: 00000004273703cf
R10: 00007f052be00000 R11: 0000000000000246 R12: 00007f052c103fac
R13: 0000000000000032 R14: 00007f052c105aa0 R15: 00007f052c103fa0
 </TASK>


Tested on:

commit:         1c5fc27b Merge tag 'nf-next-24-06-28' of git://git.ker..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=120dd466980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5264b58fdff6e881
dashboard link: https://syzkaller.appspot.com/bug?extid=4fd66a69358fc15ae2ad
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11b97f05980000

Re: [syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+4fd66a69358fc15ae2ad@syzkaller.appspotmail.com

Tested on:

commit:         1c5fc27b Merge tag 'nf-next-24-06-28' of git://git.ker..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=152db3d1980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5264b58fdff6e881
dashboard link: https://syzkaller.appspot.com/bug?extid=4fd66a69358fc15ae2ad
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1395cd71980000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[Hillf Danton]

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git  1c5fc27bc48a

--- x/net/netfilter/nf_tables_api.c
+++ y/net/netfilter/nf_tables_api.c
@@ -11552,9 +11552,10 @@ static int nft_rcv_nl_event(struct notif
 
 	gc_seq = nft_gc_seq_begin(nft_net);
 
-	if (!list_empty(&nf_tables_destroy_list))
-		nf_tables_trans_destroy_flush_work();
+	nf_tables_trans_destroy_flush_work();
 again:
+	WARN_ON(!list_empty(&nft_net->commit_list) || !list_empty(&nf_tables_destroy_list));
+
 	list_for_each_entry(table, &nft_net->tables, list) {
 		if (nft_table_has_owner(table) &&
 		    n->portid == table->nlpid) {
--

Re: [syzbot] [netfilter?] KASAN: slab-use-after-free Read in nf_tables_trans_destroy_work

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in nft_rcv_nl_event

------------[ cut here ]------------
WARNING: CPU: 0 PID: 6134 at net/netfilter/nf_tables_api.c:11557 nft_rcv_nl_event+0x1e2/0x730 net/netfilter/nf_tables_api.c:11557
Modules linked in:
CPU: 0 PID: 6134 Comm: syz.2.44 Not tainted 6.10.0-rc5-syzkaller-01137-g1c5fc27bc48a-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:nft_rcv_nl_event+0x1e2/0x730 net/netfilter/nf_tables_api.c:11557
Code: 6c 24 40 4c 89 7c 24 60 48 8b 44 24 78 42 80 3c 20 00 74 08 4c 89 ff e8 9c dc 46 f8 49 8b 07 4c 39 f8 74 0b e8 6f 0e e1 f7 90 <0f> 0b 90 eb 1c 48 8b 05 a2 34 b2 05 48 c7 c1 40 4d 67 8f 48 39 c8
RSP: 0018:ffffc90003eb79e0 EFLAGS: 00010293
RAX: ffffffff89b51c9f RBX: ffff88807abfac00 RCX: ffff888029719e00
RDX: 0000000000000000 RSI: ffffffff8bcabb40 RDI: ffffffff8c1fee00
RBP: ffffc90003eb7b28 R08: ffffffff92fbc657 R09: 1ffffffff25f78ca
R10: dffffc0000000000 R11: fffffbfff25f78cb R12: dffffc0000000000
R13: ffff888023bbd700 R14: ffff88807abfac00 R15: ffff88807abfac10
FS:  00005555803a6500(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000200 CR3: 000000007a250000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 blocking_notifier_call_chain+0x69/0x90 kernel/notifier.c:388
 netlink_release+0x11a6/0x1b10 net/netlink/af_netlink.c:787
 __sock_release net/socket.c:659 [inline]
 sock_close+0xbc/0x240 net/socket.c:1421
 __fput+0x406/0x8b0 fs/file_table.c:422
 task_work_run+0x24f/0x310 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f48f9d75b99
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffecf0981a8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000001d197 RCX: 00007f48f9d75b99
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: ffffffffffffffff R08: 0000000000000001 R09: 00000004cf0984bf
R10: 00007f48f9c00000 R11: 0000000000000246 R12: 00007f48f9f03fac
R13: 0000000000000032 R14: 00007f48f9f05aa0 R15: 00007f48f9f03fa0
 </TASK>


Tested on:

commit:         1c5fc27b Merge tag 'nf-next-24-06-28' of git://git.ker..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=16077369980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5264b58fdff6e881
dashboard link: https://syzkaller.appspot.com/bug?extid=4fd66a69358fc15ae2ad
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=112dca6e980000