| From 1f8f029cb550a82ee25876f5a4b7d7759cb7dfdb Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 12 Apr 2022 13:32:08 +0800 |
| Subject: NFC: NULL out the dev->rfkill to prevent UAF |
| |
| From: Lin Ma <linma@zju.edu.cn> |
| |
| [ Upstream commit 1b0e81416a24d6e9b8c2341e22e8bf48f8b8bfc9 ] |
| |
| Commit 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device") |
| assumes the device_is_registered() in function nfc_dev_up() will help |
| to check when the rfkill is unregistered. However, this check only |
| take effect when device_del(&dev->dev) is done in nfc_unregister_device(). |
| Hence, the rfkill object is still possible be dereferenced. |
| |
| The crash trace in latest kernel (5.18-rc2): |
| |
| [ 68.760105] ================================================================== |
| [ 68.760330] BUG: KASAN: use-after-free in __lock_acquire+0x3ec1/0x6750 |
| [ 68.760756] Read of size 8 at addr ffff888009c93018 by task fuzz/313 |
| [ 68.760756] |
| [ 68.760756] CPU: 0 PID: 313 Comm: fuzz Not tainted 5.18.0-rc2 #4 |
| [ 68.760756] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 |
| [ 68.760756] Call Trace: |
| [ 68.760756] <TASK> |
| [ 68.760756] dump_stack_lvl+0x57/0x7d |
| [ 68.760756] print_report.cold+0x5e/0x5db |
| [ 68.760756] ? __lock_acquire+0x3ec1/0x6750 |
| [ 68.760756] kasan_report+0xbe/0x1c0 |
| [ 68.760756] ? __lock_acquire+0x3ec1/0x6750 |
| [ 68.760756] __lock_acquire+0x3ec1/0x6750 |
| [ 68.760756] ? lockdep_hardirqs_on_prepare+0x410/0x410 |
| [ 68.760756] ? register_lock_class+0x18d0/0x18d0 |
| [ 68.760756] lock_acquire+0x1ac/0x4f0 |
| [ 68.760756] ? rfkill_blocked+0xe/0x60 |
| [ 68.760756] ? lockdep_hardirqs_on_prepare+0x410/0x410 |
| [ 68.760756] ? mutex_lock_io_nested+0x12c0/0x12c0 |
| [ 68.760756] ? nla_get_range_signed+0x540/0x540 |
| [ 68.760756] ? _raw_spin_lock_irqsave+0x4e/0x50 |
| [ 68.760756] _raw_spin_lock_irqsave+0x39/0x50 |
| [ 68.760756] ? rfkill_blocked+0xe/0x60 |
| [ 68.760756] rfkill_blocked+0xe/0x60 |
| [ 68.760756] nfc_dev_up+0x84/0x260 |
| [ 68.760756] nfc_genl_dev_up+0x90/0xe0 |
| [ 68.760756] genl_family_rcv_msg_doit+0x1f4/0x2f0 |
| [ 68.760756] ? genl_family_rcv_msg_attrs_parse.constprop.0+0x230/0x230 |
| [ 68.760756] ? security_capable+0x51/0x90 |
| [ 68.760756] genl_rcv_msg+0x280/0x500 |
| [ 68.760756] ? genl_get_cmd+0x3c0/0x3c0 |
| [ 68.760756] ? lock_acquire+0x1ac/0x4f0 |
| [ 68.760756] ? nfc_genl_dev_down+0xe0/0xe0 |
| [ 68.760756] ? lockdep_hardirqs_on_prepare+0x410/0x410 |
| [ 68.760756] netlink_rcv_skb+0x11b/0x340 |
| [ 68.760756] ? genl_get_cmd+0x3c0/0x3c0 |
| [ 68.760756] ? netlink_ack+0x9c0/0x9c0 |
| [ 68.760756] ? netlink_deliver_tap+0x136/0xb00 |
| [ 68.760756] genl_rcv+0x1f/0x30 |
| [ 68.760756] netlink_unicast+0x430/0x710 |
| [ 68.760756] ? memset+0x20/0x40 |
| [ 68.760756] ? netlink_attachskb+0x740/0x740 |
| [ 68.760756] ? __build_skb_around+0x1f4/0x2a0 |
| [ 68.760756] netlink_sendmsg+0x75d/0xc00 |
| [ 68.760756] ? netlink_unicast+0x710/0x710 |
| [ 68.760756] ? netlink_unicast+0x710/0x710 |
| [ 68.760756] sock_sendmsg+0xdf/0x110 |
| [ 68.760756] __sys_sendto+0x19e/0x270 |
| [ 68.760756] ? __ia32_sys_getpeername+0xa0/0xa0 |
| [ 68.760756] ? fd_install+0x178/0x4c0 |
| [ 68.760756] ? fd_install+0x195/0x4c0 |
| [ 68.760756] ? kernel_fpu_begin_mask+0x1c0/0x1c0 |
| [ 68.760756] __x64_sys_sendto+0xd8/0x1b0 |
| [ 68.760756] ? lockdep_hardirqs_on+0xbf/0x130 |
| [ 68.760756] ? syscall_enter_from_user_mode+0x1d/0x50 |
| [ 68.760756] do_syscall_64+0x3b/0x90 |
| [ 68.760756] entry_SYSCALL_64_after_hwframe+0x44/0xae |
| [ 68.760756] RIP: 0033:0x7f67fb50e6b3 |
| ... |
| [ 68.760756] RSP: 002b:00007f67fa91fe90 EFLAGS: 00000293 ORIG_RAX: 000000000000002c |
| [ 68.760756] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f67fb50e6b3 |
| [ 68.760756] RDX: 000000000000001c RSI: 0000559354603090 RDI: 0000000000000003 |
| [ 68.760756] RBP: 00007f67fa91ff00 R08: 00007f67fa91fedc R09: 000000000000000c |
| [ 68.760756] R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe824d496e |
| [ 68.760756] R13: 00007ffe824d496f R14: 00007f67fa120000 R15: 0000000000000003 |
| |
| [ 68.760756] </TASK> |
| [ 68.760756] |
| [ 68.760756] Allocated by task 279: |
| [ 68.760756] kasan_save_stack+0x1e/0x40 |
| [ 68.760756] __kasan_kmalloc+0x81/0xa0 |
| [ 68.760756] rfkill_alloc+0x7f/0x280 |
| [ 68.760756] nfc_register_device+0xa3/0x1a0 |
| [ 68.760756] nci_register_device+0x77a/0xad0 |
| [ 68.760756] nfcmrvl_nci_register_dev+0x20b/0x2c0 |
| [ 68.760756] nfcmrvl_nci_uart_open+0xf2/0x1dd |
| [ 68.760756] nci_uart_tty_ioctl+0x2c3/0x4a0 |
| [ 68.760756] tty_ioctl+0x764/0x1310 |
| [ 68.760756] __x64_sys_ioctl+0x122/0x190 |
| [ 68.760756] do_syscall_64+0x3b/0x90 |
| [ 68.760756] entry_SYSCALL_64_after_hwframe+0x44/0xae |
| [ 68.760756] |
| [ 68.760756] Freed by task 314: |
| [ 68.760756] kasan_save_stack+0x1e/0x40 |
| [ 68.760756] kasan_set_track+0x21/0x30 |
| [ 68.760756] kasan_set_free_info+0x20/0x30 |
| [ 68.760756] __kasan_slab_free+0x108/0x170 |
| [ 68.760756] kfree+0xb0/0x330 |
| [ 68.760756] device_release+0x96/0x200 |
| [ 68.760756] kobject_put+0xf9/0x1d0 |
| [ 68.760756] nfc_unregister_device+0x77/0x190 |
| [ 68.760756] nfcmrvl_nci_unregister_dev+0x88/0xd0 |
| [ 68.760756] nci_uart_tty_close+0xdf/0x180 |
| [ 68.760756] tty_ldisc_kill+0x73/0x110 |
| [ 68.760756] tty_ldisc_hangup+0x281/0x5b0 |
| [ 68.760756] __tty_hangup.part.0+0x431/0x890 |
| [ 68.760756] tty_release+0x3a8/0xc80 |
| [ 68.760756] __fput+0x1f0/0x8c0 |
| [ 68.760756] task_work_run+0xc9/0x170 |
| [ 68.760756] exit_to_user_mode_prepare+0x194/0x1a0 |
| [ 68.760756] syscall_exit_to_user_mode+0x19/0x50 |
| [ 68.760756] do_syscall_64+0x48/0x90 |
| [ 68.760756] entry_SYSCALL_64_after_hwframe+0x44/0xae |
| |
| This patch just add the null out of dev->rfkill to make sure such |
| dereference cannot happen. This is safe since the device_lock() already |
| protect the check/write from data race. |
| |
| Fixes: 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device") |
| Signed-off-by: Lin Ma <linma@zju.edu.cn> |
| Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| net/nfc/core.c | 1 + |
| 1 file changed, 1 insertion(+) |
| |
| diff --git a/net/nfc/core.c b/net/nfc/core.c |
| index 8c38a21fb0c6..120259c2b6a7 100644 |
| --- a/net/nfc/core.c |
| +++ b/net/nfc/core.c |
| @@ -1174,6 +1174,7 @@ void nfc_unregister_device(struct nfc_dev *dev) |
| if (dev->rfkill) { |
| rfkill_unregister(dev->rfkill); |
| rfkill_destroy(dev->rfkill); |
| + dev->rfkill = NULL; |
| } |
| dev->shutting_down = true; |
| device_unlock(&dev->dev); |
| -- |
| 2.35.1 |
| |