On 1/21/2025 10:54 PM, Greg KH wrote:
On Tue, Jan 21, 2025 at 10:22:43PM +0800, alvalan9@xxxxxxxxxxx wrote:
From: Wang Liang <wangliang74@xxxxxxxxxx>
commit 073d89808c065ac4c672c0a613a71b27a80691cb upstream.
Syzkaller reported this warning:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 16 at net/ipv4/af_inet.c:156 inet_sock_destruct+0x1c5/0x1e0
Modules linked in:
CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc5 #26
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:inet_sock_destruct+0x1c5/0x1e0
Code: 24 12 4c 89 e2 5b 48 c7 c7 98 ec bb 82 41 5c e9 d1 18 17 ff 4c 89 e6 5b 48 c7 c7 d0 ec bb 82 41 5c e9 bf 18 17 ff 0f 0b eb 83 <0f> 0b eb 97 0f 0b eb 87 0f 0b e9 68 ff ff ff 66 66 2e 0f 1f 84 00
RSP: 0018:ffffc9000008bd90 EFLAGS: 00010206
RAX: 0000000000000300 RBX: ffff88810b172a90 RCX: 0000000000000007
RDX: 0000000000000002 RSI: 0000000000000300 RDI: ffff88810b172a00
RBP: ffff88810b172a00 R08: ffff888104273c00 R09: 0000000000100007
R10: 0000000000020000 R11: 0000000000000006 R12: ffff88810b172a00
R13: 0000000000000004 R14: 0000000000000000 R15: ffff888237c31f78
FS: 0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc63fecac8 CR3: 000000000342e000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
? __warn+0x88/0x130
? inet_sock_destruct+0x1c5/0x1e0
? report_bug+0x18e/0x1a0
? handle_bug+0x53/0x90
? exc_invalid_op+0x18/0x70
? asm_exc_invalid_op+0x1a/0x20
? inet_sock_destruct+0x1c5/0x1e0
__sk_destruct+0x2a/0x200
rcu_do_batch+0x1aa/0x530
? rcu_do_batch+0x13b/0x530
rcu_core+0x159/0x2f0
handle_softirqs+0xd3/0x2b0
? __pfx_smpboot_thread_fn+0x10/0x10
run_ksoftirqd+0x25/0x30
smpboot_thread_fn+0xdd/0x1d0
kthread+0xd3/0x100
? __pfx_kthread+0x10/0x10
ret_from_fork+0x34/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
---[ end trace 0000000000000000 ]---
Its possible that two threads call tcp_v6_do_rcv()/sk_forward_alloc_add()
concurrently when sk->sk_state == TCP_LISTEN with sk->sk_lock unlocked,
which triggers a data-race around sk->sk_forward_alloc:
tcp_v6_rcv
tcp_v6_do_rcv
skb_clone_and_charge_r
sk_rmem_schedule
__sk_mem_schedule
sk_forward_alloc_add()
skb_set_owner_r
sk_mem_charge
sk_forward_alloc_add()
__kfree_skb
skb_release_all
skb_release_head_state
sock_rfree
sk_mem_uncharge
sk_forward_alloc_add()
sk_mem_reclaim
// set local var reclaimable
__sk_mem_reclaim
sk_forward_alloc_add()
In this syzkaller testcase, two threads call
tcp_v6_do_rcv() with skb->truesize=768, the sk_forward_alloc changes like
this:
(cpu 1) | (cpu 2) | sk_forward_alloc
... | ... | 0
__sk_mem_schedule() | | +4096 = 4096
| __sk_mem_schedule() | +4096 = 8192
sk_mem_charge() | | -768 = 7424
| sk_mem_charge() | -768 = 6656
... | ... |
sk_mem_uncharge() | | +768 = 7424
reclaimable=7424 | |
| sk_mem_uncharge() | +768 = 8192
| reclaimable=8192 |
__sk_mem_reclaim() | | -4096 = 4096
| __sk_mem_reclaim() | -8192 = -4096 != 0
The skb_clone_and_charge_r() should not be called in tcp_v6_do_rcv() when
sk->sk_state is TCP_LISTEN, it happens later in tcp_v6_syn_recv_sock().
Fix the same issue in dccp_v6_do_rcv().
Suggested-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets")
Signed-off-by: Wang Liang <wangliang74@xxxxxxxxxx>
Link: https://patch.msgid.link/20241107023405.889239-1-wangliang74@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Alva Lan <alvalan9@xxxxxxxxxxx>
---
You sent this twice, which one is correct? I'll drop both from my inbox
just to be sure :)
No problem, please drop both. Thank you.
Actually, I did not see the patch in the mail list after I had sent this
patch twenty minutes. It might have failed to send so I sent the patch
again. Sorry for my mistake.
Backport to fix CVE-2024-53124.
Link: https://nvd.nist.gov/vuln/detail/CVE-2024-53124
Please don't point to random cve "enhancers" with unknown ways that they
have modified our original cve record. Just point at the cve.org record
if you really want to link to something.
thanks,
greg k-h
OK.
B.R.
Alva Lan
