From b048106c1f066d66e9a65db27da427244a940232 Mon Sep 17 00:00:00 2001 From: QiuSimons <45143996+QiuSimons@users.noreply.github.com> Date: Sat, 28 Dec 2024 19:49:43 +0800 Subject: [PATCH] update patch info --- ...ta-races-around-sk--sk_forward_alloc.patch | 104 ++++++++++++++++++ 1 file changed, 104 insertions(+) diff --git a/PATCH/kernel/others/999-net-net-fix-data-races-around-sk--sk_forward_alloc.patch b/PATCH/kernel/others/999-net-net-fix-data-races-around-sk--sk_forward_alloc.patch index 86cfc81ac..dfc2ccd69 100644 --- a/PATCH/kernel/others/999-net-net-fix-data-races-around-sk--sk_forward_alloc.patch +++ b/PATCH/kernel/others/999-net-net-fix-data-races-around-sk--sk_forward_alloc.patch @@ -1,3 +1,107 @@ +From 073d89808c065ac4c672c0a613a71b27a80691cb Mon Sep 17 00:00:00 2001 +From: Wang Liang +Date: Thu, 7 Nov 2024 10:34:05 +0800 +Subject: net: fix data-races around sk->sk_forward_alloc + +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: + + ? __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 + + ---[ 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 +Reviewed-by: Eric Dumazet +Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") +Signed-off-by: Wang Liang +Link: https://patch.msgid.link/20241107023405.889239-1-wangliang74@huawei.com +Signed-off-by: Jakub Kicinski +--- + net/dccp/ipv6.c | 2 +- + net/ipv6/tcp_ipv6.c | 4 +--- + 2 files changed, 2 insertions(+), 4 deletions(-) + --- a/net/dccp/ipv6.c +++ b/net/dccp/ipv6.c @@ -616,7 +616,7 @@ static int dccp_v6_do_rcv(struct sock *s