* [syzbot] [net?] KMSAN: uninit-value in __llc_lookup_established
@ 2023-12-05 18:25 syzbot
2023-12-06 0:53 ` Kuniyuki Iwashima
2023-12-06 1:55 ` [PATCH] llc: fix " Edward Adam Davis
0 siblings, 2 replies; 5+ messages in thread
From: syzbot @ 2023-12-05 18:25 UTC (permalink / raw)
To: davem, edumazet, kuba, linux-kernel, netdev, pabeni,
syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 1c41041124bd Merge tag 'i3c/for-6.7' of git://git.kernel.o..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=10429eeb680000
kernel config: https://syzkaller.appspot.com/x/.config?x=956549bd1d1e9efd
dashboard link: https://syzkaller.appspot.com/bug?extid=b5ad66046b913bc04c6f
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=12b6a00f680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=121471ef680000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/20fd86e677f1/disk-1c410411.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ccd39cb0b7b6/vmlinux-1c410411.xz
kernel image: https://storage.googleapis.com/syzbot-assets/156fc60f97bc/bzImage-1c410411.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b5ad66046b913bc04c6f@syzkaller.appspotmail.com
syz-executor994 uses obsolete (PF_INET,SOCK_PACKET)
=====================================================
BUG: KMSAN: uninit-value in __llc_lookup_established+0xe9d/0xf90
__llc_lookup_established+0xe9d/0xf90
__llc_lookup net/llc/llc_conn.c:611 [inline]
llc_conn_handler+0x4bd/0x1360 net/llc/llc_conn.c:791
llc_rcv+0xfbb/0x14a0 net/llc/llc_input.c:206
__netif_receive_skb_one_core net/core/dev.c:5527 [inline]
__netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5641
netif_receive_skb_internal net/core/dev.c:5727 [inline]
netif_receive_skb+0x58/0x660 net/core/dev.c:5786
tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555
tun_get_user+0x53af/0x66d0 drivers/net/tun.c:2002
tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
call_write_iter include/linux/fs.h:2020 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x8ef/0x1490 fs/read_write.c:584
ksys_write+0x20f/0x4c0 fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__x64_sys_write+0x93/0xd0 fs/read_write.c:646
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
Local variable daddr created at:
llc_conn_handler+0x53/0x1360 net/llc/llc_conn.c:783
llc_rcv+0xfbb/0x14a0 net/llc/llc_input.c:206
CPU: 1 PID: 5004 Comm: syz-executor994 Not tainted 6.6.0-syzkaller-14500-g1c41041124bd #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
=====================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
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
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [syzbot] [net?] KMSAN: uninit-value in __llc_lookup_established
2023-12-05 18:25 [syzbot] [net?] KMSAN: uninit-value in __llc_lookup_established syzbot
@ 2023-12-06 0:53 ` Kuniyuki Iwashima
2023-12-06 1:28 ` syzbot
2023-12-06 1:55 ` [PATCH] llc: fix " Edward Adam Davis
1 sibling, 1 reply; 5+ messages in thread
From: Kuniyuki Iwashima @ 2023-12-06 0:53 UTC (permalink / raw)
To: syzbot+b5ad66046b913bc04c6f
Cc: davem, edumazet, kuba, linux-kernel, netdev, pabeni,
syzkaller-bugs, kuniyu
From: syzbot <syzbot+b5ad66046b913bc04c6f@syzkaller.appspotmail.com>
Date: Tue, 05 Dec 2023 10:25:31 -0800
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 1c41041124bd Merge tag 'i3c/for-6.7' of git://git.kernel.o..
> git tree: upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=10429eeb680000
> kernel config: https://syzkaller.appspot.com/x/.config?x=956549bd1d1e9efd
> dashboard link: https://syzkaller.appspot.com/bug?extid=b5ad66046b913bc04c6f
> 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=12b6a00f680000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=121471ef680000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/20fd86e677f1/disk-1c410411.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/ccd39cb0b7b6/vmlinux-1c410411.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/156fc60f97bc/bzImage-1c410411.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+b5ad66046b913bc04c6f@syzkaller.appspotmail.com
>
> syz-executor994 uses obsolete (PF_INET,SOCK_PACKET)
> =====================================================
> BUG: KMSAN: uninit-value in __llc_lookup_established+0xe9d/0xf90
> __llc_lookup_established+0xe9d/0xf90
> __llc_lookup net/llc/llc_conn.c:611 [inline]
> llc_conn_handler+0x4bd/0x1360 net/llc/llc_conn.c:791
> llc_rcv+0xfbb/0x14a0 net/llc/llc_input.c:206
> __netif_receive_skb_one_core net/core/dev.c:5527 [inline]
> __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5641
> netif_receive_skb_internal net/core/dev.c:5727 [inline]
> netif_receive_skb+0x58/0x660 net/core/dev.c:5786
> tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555
> tun_get_user+0x53af/0x66d0 drivers/net/tun.c:2002
> tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
> call_write_iter include/linux/fs.h:2020 [inline]
> new_sync_write fs/read_write.c:491 [inline]
> vfs_write+0x8ef/0x1490 fs/read_write.c:584
> ksys_write+0x20f/0x4c0 fs/read_write.c:637
> __do_sys_write fs/read_write.c:649 [inline]
> __se_sys_write fs/read_write.c:646 [inline]
> __x64_sys_write+0x93/0xd0 fs/read_write.c:646
> do_syscall_x64 arch/x86/entry/common.c:51 [inline]
> do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
> entry_SYSCALL_64_after_hwframe+0x63/0x6b
>
> Local variable daddr created at:
> llc_conn_handler+0x53/0x1360 net/llc/llc_conn.c:783
> llc_rcv+0xfbb/0x14a0 net/llc/llc_input.c:206
>
> CPU: 1 PID: 5004 Comm: syz-executor994 Not tainted 6.6.0-syzkaller-14500-g1c41041124bd #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
> =====================================================
llc_pdu_decode_[sd]a() initialises addr.mac only for ETH_P_802_2.
Otherwise, llc_estab_match() reads an uninit value form both [sd]addr.
#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 1c41041124bd
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c
index 0a3f5e0bec00..730561e186ce 100644
--- a/net/llc/llc_conn.c
+++ b/net/llc/llc_conn.c
@@ -780,7 +780,7 @@ static struct sock *llc_create_incoming_sock(struct sock *sk,
void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb)
{
- struct llc_addr saddr, daddr;
+ struct llc_addr saddr = {}, daddr = {};
struct sock *sk;
llc_pdu_decode_sa(skb, saddr.mac);
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [syzbot] [net?] KMSAN: uninit-value in __llc_lookup_established
2023-12-06 0:53 ` Kuniyuki Iwashima
@ 2023-12-06 1:28 ` syzbot
0 siblings, 0 replies; 5+ messages in thread
From: syzbot @ 2023-12-06 1:28 UTC (permalink / raw)
To: davem, edumazet, kuba, kuniyu, linux-kernel, netdev, pabeni,
syzkaller-bugs
Hello,
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-and-tested-by: syzbot+b5ad66046b913bc04c6f@syzkaller.appspotmail.com
Tested on:
commit: 1c410411 Merge tag 'i3c/for-6.7' of git://git.kernel.o..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1577c0d4e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=956549bd1d1e9efd
dashboard link: https://syzkaller.appspot.com/bug?extid=b5ad66046b913bc04c6f
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=13fa938ce80000
Note: testing is done by a robot and is best-effort only.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] llc: fix uninit-value in __llc_lookup_established
2023-12-05 18:25 [syzbot] [net?] KMSAN: uninit-value in __llc_lookup_established syzbot
2023-12-06 0:53 ` Kuniyuki Iwashima
@ 2023-12-06 1:55 ` Edward Adam Davis
2023-12-06 6:27 ` Kuniyuki Iwashima
1 sibling, 1 reply; 5+ messages in thread
From: Edward Adam Davis @ 2023-12-06 1:55 UTC (permalink / raw)
To: syzbot+b5ad66046b913bc04c6f
Cc: davem, edumazet, kuba, linux-kernel, netdev, pabeni,
syzkaller-bugs
llc only supports ETH_P_802_2 protocol, so drop the skb when the protocol is
not it.
Reported-by: syzbot+b5ad66046b913bc04c6f@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
net/llc/llc_input.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/llc/llc_input.c b/net/llc/llc_input.c
index 51bccfb00a9c..16b2c57f38c2 100644
--- a/net/llc/llc_input.c
+++ b/net/llc/llc_input.c
@@ -141,7 +141,8 @@ static inline int llc_fixup_skb(struct sk_buff *skb)
return 0;
if (unlikely(pskb_trim_rcsum(skb, data_size)))
return 0;
- }
+ } else
+ return 0;
return 1;
}
--
2.43.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] llc: fix uninit-value in __llc_lookup_established
2023-12-06 1:55 ` [PATCH] llc: fix " Edward Adam Davis
@ 2023-12-06 6:27 ` Kuniyuki Iwashima
0 siblings, 0 replies; 5+ messages in thread
From: Kuniyuki Iwashima @ 2023-12-06 6:27 UTC (permalink / raw)
To: eadavis
Cc: davem, edumazet, kuba, linux-kernel, netdev, pabeni,
syzbot+b5ad66046b913bc04c6f, syzkaller-bugs, kuniyu
From: Edward Adam Davis <eadavis@qq.com>
Date: Wed, 6 Dec 2023 09:55:15 +0800
> llc only supports ETH_P_802_2 protocol, so drop the skb when the protocol is
> not it.
This is not true. ETH_P_TR_802_2 is also processed by llc_rcv().
Let me post this formally.
https://lore.kernel.org/netdev/20231206005340.11534-1-kuniyu@amazon.com/
>
> Reported-by: syzbot+b5ad66046b913bc04c6f@syzkaller.appspotmail.com
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
> net/llc/llc_input.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/llc/llc_input.c b/net/llc/llc_input.c
> index 51bccfb00a9c..16b2c57f38c2 100644
> --- a/net/llc/llc_input.c
> +++ b/net/llc/llc_input.c
> @@ -141,7 +141,8 @@ static inline int llc_fixup_skb(struct sk_buff *skb)
> return 0;
> if (unlikely(pskb_trim_rcsum(skb, data_size)))
> return 0;
> - }
> + } else
> + return 0;
> return 1;
> }
>
> --
> 2.43.0
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-12-06 6:27 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2023-12-05 18:25 [syzbot] [net?] KMSAN: uninit-value in __llc_lookup_established syzbot
2023-12-06 0:53 ` Kuniyuki Iwashima
2023-12-06 1:28 ` syzbot
2023-12-06 1:55 ` [PATCH] llc: fix " Edward Adam Davis
2023-12-06 6:27 ` Kuniyuki Iwashima
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