CVE-2023-53492

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_tables: do not ignore genmask when looking up chain by id

When adding a rule to a chain referring to its ID, if that chain had been deleted on the same batch, the rule might end up referring to a deleted chain.

This will lead to a WARNING like following:

[ 33.098431] ------------[ cut here ]------------ [ 33.098678] WARNING: CPU: 5 PID: 69 at net/netfilter/nftablesapi.c:2037 nftableschaindestroy+0x23d/0x260 [ 33.099217] Modules linked in: [ 33.099388] CPU: 5 PID: 69 Comm: kworker/5:1 Not tainted 6.4.0+ #409 [ 33.099726] Workqueue: events nftablestransdestroywork [ 33.100018] RIP: 0010:nftableschaindestroy+0x23d/0x260 [ 33.100306] Code: 8b 7c 24 68 e8 64 9c ed fe 4c 89 e7 e8 5c 9c ed fe 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 89 c6 89 c7 c3 cc cc cc cc <0f> 0b 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 89 c6 89 c7 [ 33.101271] RSP: 0018:ffffc900004ffc48 EFLAGS: 00010202 [ 33.101546] RAX: 0000000000000001 RBX: ffff888006fc0a28 RCX: 0000000000000000 [ 33.101920] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 33.102649] RBP: ffffc900004ffc78 R08: 0000000000000000 R09: 0000000000000000 [ 33.103018] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880135ef500 [ 33.103385] R13: 0000000000000000 R14: dead000000000122 R15: ffff888006fc0a10 [ 33.103762] FS: 0000000000000000(0000) GS:ffff888024c80000(0000) knlGS:0000000000000000 [ 33.104184] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 33.104493] CR2: 00007fe863b56a50 CR3: 00000000124b0001 CR4: 0000000000770ee0 [ 33.104872] PKRU: 55555554 [ 33.104999] Call Trace: [ 33.105113] <TASK> [ 33.105214] ? show_regs+0x72/0x90 [ 33.105371] ? __warn+0xa5/0x210 [ 33.105520] ? nftableschaindestroy+0x23d/0x260 [ 33.105732] ? reportbug+0x1f2/0x200 [ 33.105902] ? handlebug+0x46/0x90 [ 33.106546] ? excinvalidop+0x19/0x50 [ 33.106762] ? asmexcinvalidop+0x1b/0x20 [ 33.106995] ? nftableschaindestroy+0x23d/0x260 [ 33.107249] ? nftableschaindestroy+0x30/0x260 [ 33.107506] nftablestransdestroywork+0x669/0x680 [ 33.107782] ? markheldlocks+0x28/0xa0 [ 33.107996] ? __pfxnftablestransdestroywork+0x10/0x10 [ 33.108294] ? rawspinunlockirq+0x28/0x70 [ 33.108538] processonework+0x68c/0xb70 [ 33.108755] ? lockacquire+0x17f/0x420 [ 33.108977] ? __pfxprocessonework+0x10/0x10 [ 33.109218] ? dorawspinlock+0x128/0x1d0 [ 33.109435] ? rawspinlockirq+0x71/0x80 [ 33.109634] worker_thread+0x2bd/0x700 [ 33.109817] ? __pfxworkerthread+0x10/0x10 [ 33.110254] kthread+0x18b/0x1d0 [ 33.110410] ? __pfxkthread+0x10/0x10 [ 33.110581] retfrom_fork+0x29/0x50 [ 33.110757] </TASK> [ 33.110866] irq event stamp: 1651 [ 33.111017] hardirqs last enabled at (1659): [<ffffffffa206a209>] __upconsolesem+0x79/0xa0 [ 33.111379] hardirqs last disabled at (1666): [<ffffffffa206a1ee>] __upconsolesem+0x5e/0xa0 [ 33.111740] softirqs last enabled at (1616): [<ffffffffa1f5d40e>] __irqexitrcu+0x9e/0xe0 [ 33.112094] softirqs last disabled at (1367): [<ffffffffa1f5d40e>] __irqexitrcu+0x9e/0xe0 [ 33.112453] ---[ end trace 0000000000000000 ]---

This is due to the nftchainlookup_byid ignoring the genmask. After this change, adding the new rule will fail as it will not find the chain.