[PATCH 5.11 065/152] net: wan/lmc: unregister device when no matching device is found

Greg Kroah-Hartman
2021-04-05T09:21:51Z

From: Tong Zhang <ztong0001@gmail.com>

[ Upstream commit 62e69bc419772638369eff8ff81340bde8aceb61 ]

lmc set sc->lmc_media pointer when there is a matching device.
However, when no matching device is found, this pointer is NULL
and the following dereference will result in a null-ptr-deref.

To fix this issue, unregister the hdlc device and return an error.

[ 4.569359] BUG: KASAN: null-ptr-deref in lmc_init_one.cold+0x2b6/0x55d [lmc]
[ 4.569748] Read of size 8 at addr 0000000000000008 by task modprobe/95
[ 4.570102]
[ 4.570187] CPU: 0 PID: 95 Comm: modprobe Not tainted 5.11.0-rc7 #94
[ 4.570527] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-48-gd9c812dda519-preb4
[ 4.571125] Call Trace:
[ 4.571261] dump_stack+0x7d/0xa3
[ 4.571445] kasan_report.cold+0x10c/0x10e
[ 4.571667] ? lmc_init_one.cold+0x2b6/0x55d [lmc]
[ 4.571932] lmc_init_one.cold+0x2b6/0x55d [lmc]
[ 4.572186] ? lmc_mii_readreg+0xa0/0xa0 [lmc]
[ 4.572432] local_pci_probe+0x6f/0xb0
[ 4.572639] pci_device_probe+0x171/0x240
[ 4.572857] ? pci_device_remove+0xe0/0xe0
[ 4.573080] ? kernfs_create_link+0xb6/0x110
[ 4.573315] ? sysfs_do_create_link_sd.isra.0+0x76/0xe0
[ 4.573598] really_probe+0x161/0x420
[ 4.573799] driver_probe_device+0x6d/0xd0
[ 4.574022] device_driver_attach+0x82/0x90
[ 4.574249] ? device_driver_attach+0x90/0x90
[ 4.574485] __driver_attach+0x60/0x100
[ 4.574694] ? device_driver_attach+0x90/0x90
[ 4.574931] bus_for_each_dev+0xe1/0x140
[ 4.575146] ? subsys_dev_iter_exit+0x10/0x10
[ 4.575387] ? klist_node_init+0x61/0x80
[ 4.575602] bus_add_driver+0x254/0x2a0
[ 4.575812] driver_register+0xd3/0x150
[ 4.576021] ? 0xffffffffc0018000
[ 4.576202] do_one_initcall+0x84/0x250
[ 4.576411] ? trace_event_raw_event_initcall_finish+0x150/0x150
[ 4.576733] ? unpoison_range+0xf/0x30
[ 4.576938] ? ____kasan_kmalloc.constprop.0+0x84/0xa0
[ 4.577219] ? unpoison_range+0xf/0x30
[ 4.577423] ? unpoison_range+0xf/0x30
[ 4.577628] do_init_module+0xf8/0x350
[ 4.577833] load_module+0x3fe6/0x4340
[ 4.578038] ? vm_unmap_ram+0x1d0/0x1d0
[ 4.578247] ? ____kasan_kmalloc.constprop.0+0x84/0xa0
[ 4.578526] ? module_frob_arch_sections+0x20/0x20
[ 4.578787] ? __do_sys_finit_module+0x108/0x170
[ 4.579037] __do_sys_finit_module+0x108/0x170
[ 4.579278] ? __ia32_sys_init_module+0x40/0x40
[ 4.579523] ? file_open_root+0x200/0x200
[ 4.579742] ? do_sys_open+0x85/0xe0
[ 4.579938] ? filp_open+0x50/0x50
[ 4.580125] ? exit_to_user_mode_prepare+0xfc/0x130
[ 4.580390] do_syscall_64+0x33/0x40
[ 4.580586] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 4.580859] RIP: 0033:0x7f1a724c3cf7
[ 4.581054] Code: 48 89 57 30 48 8b 04 24 48 89 47 38 e9 1d a0 02 00 48 89 f8 48 89 f7 48 89 d6 48 891
[ 4.582043] RSP: 002b:00007fff44941c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[ 4.582447] RAX: ffffffffffffffda RBX: 00000000012ada70 RCX: 00007f1a724c3cf7
[ 4.582827] RDX: 0000000000000000 RSI: 00000000012ac9e0 RDI: 0000000000000003
[ 4.583207] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001
[ 4.583587] R10: 00007f1a72527300 R11: 0000000000000246 R12: 00000000012ac9e0
[ 4.583968] R13: 0000000000000000 R14: 00000000012acc90 R15: 0000000000000001
[ 4.584349] ==================================================================

Signed-off-by: Tong Zhang <ztong0001@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wan/lmc/lmc_main.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/net/wan/lmc/lmc_main.c b/drivers/net/wan/lmc/lmc_main.c
index 93c7e8502845..ebb568f9bc66 100644
--- a/drivers/net/wan/lmc/lmc_main.c
+++ b/drivers/net/wan/lmc/lmc_main.c
@@ -899,6 +899,8 @@ static int lmc_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
break;
default:
printk(KERN_WARNING "%s: LMC UNKNOWN CARD!\n", dev->name);
+ unregister_hdlc_device(dev);
+ return -EIO;
break;
}

--
2.30.1