| From 8e80e13b538dce8a7b4ec264f710951c330f0925 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Sat, 5 Jul 2025 16:52:28 +0800 |
| Subject: atm: clip: Fix NULL pointer dereference in vcc_sendmsg() |
| |
| From: Yue Haibing <yuehaibing@huawei.com> |
| |
| [ Upstream commit 22fc46cea91df3dce140a7dc6847c6fcf0354505 ] |
| |
| atmarpd_dev_ops does not implement the send method, which may cause crash |
| as bellow. |
| |
| BUG: kernel NULL pointer dereference, address: 0000000000000000 |
| PGD 0 P4D 0 |
| Oops: Oops: 0010 [#1] SMP KASAN NOPTI |
| CPU: 0 UID: 0 PID: 5324 Comm: syz.0.0 Not tainted 6.15.0-rc6-syzkaller-00346-g5723cc3450bc #0 PREEMPT(full) |
| Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 |
| RIP: 0010:0x0 |
| Code: Unable to access opcode bytes at 0xffffffffffffffd6. |
| RSP: 0018:ffffc9000d3cf778 EFLAGS: 00010246 |
| RAX: 1ffffffff1910dd1 RBX: 00000000000000c0 RCX: dffffc0000000000 |
| RDX: ffffc9000dc82000 RSI: ffff88803e4c4640 RDI: ffff888052cd0000 |
| RBP: ffffc9000d3cf8d0 R08: ffff888052c9143f R09: 1ffff1100a592287 |
| R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff92001a79f00 |
| R13: ffff888052cd0000 R14: ffff88803e4c4640 R15: ffffffff8c886e88 |
| FS: 00007fbc762566c0(0000) GS:ffff88808d6c2000(0000) knlGS:0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: ffffffffffffffd6 CR3: 0000000041f1b000 CR4: 0000000000352ef0 |
| DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 |
| DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 |
| Call Trace: |
| <TASK> |
| vcc_sendmsg+0xa10/0xc50 net/atm/common.c:644 |
| sock_sendmsg_nosec net/socket.c:712 [inline] |
| __sock_sendmsg+0x219/0x270 net/socket.c:727 |
| ____sys_sendmsg+0x52d/0x830 net/socket.c:2566 |
| ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620 |
| __sys_sendmmsg+0x227/0x430 net/socket.c:2709 |
| __do_sys_sendmmsg net/socket.c:2736 [inline] |
| __se_sys_sendmmsg net/socket.c:2733 [inline] |
| __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2733 |
| do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] |
| do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 |
| entry_SYSCALL_64_after_hwframe+0x77/0x7f |
| |
| Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") |
| Reported-by: syzbot+e34e5e6b5eddb0014def@syzkaller.appspotmail.com |
| Closes: https://lore.kernel.org/all/682f82d5.a70a0220.1765ec.0143.GAE@google.com/T |
| Signed-off-by: Yue Haibing <yuehaibing@huawei.com> |
| Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> |
| Link: https://patch.msgid.link/20250705085228.329202-1-yuehaibing@huawei.com |
| Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| net/atm/clip.c | 10 +++++++++- |
| 1 file changed, 9 insertions(+), 1 deletion(-) |
| |
| diff --git a/net/atm/clip.c b/net/atm/clip.c |
| index 936b9558be4b9..53d62361ae460 100644 |
| --- a/net/atm/clip.c |
| +++ b/net/atm/clip.c |
| @@ -632,8 +632,16 @@ static void atmarpd_close(struct atm_vcc *vcc) |
| module_put(THIS_MODULE); |
| } |
| |
| +static int atmarpd_send(struct atm_vcc *vcc, struct sk_buff *skb) |
| +{ |
| + atm_return_tx(vcc, skb); |
| + dev_kfree_skb_any(skb); |
| + return 0; |
| +} |
| + |
| static const struct atmdev_ops atmarpd_dev_ops = { |
| - .close = atmarpd_close |
| + .close = atmarpd_close, |
| + .send = atmarpd_send |
| }; |
| |
| |
| -- |
| 2.39.5 |
| |
