On 14/08/2020 08:26, John Garry wrote:
+
On 13/08/2020 19:28, Greg Kroah-Hartman wrote:
[58.950967] hub 8-0:1.0: USB hub found
[58.954894] hub 8-0:1.0: 1 port detected
[58.961651] usbcore: registered new interface driver usb-storage
Ring any bells? I don't mind debugging the real issue, but good to
know it's
not already solved. I didn't see anything on linux-usb archives,
apart from
this:
https://lore.kernel.org/linux-usb/1566554761464.60146@xxxxxxxxxx/ ; which
doesn't look too familiar.
I couldn't recreate on v5.8, but this triggering this seems a bit
fragile
even on linux-next.
Looks new. Any chance you can run 'git bisect' to track this down?
Hi Greg,
I need to find a reliable reproducer. I could only reproduce when some
other seemingly unrelated kernel config options were enabled. Let me see
if I can reproduce based on Linus' kernel (it will be 5.9-rc now), and
go from there.
Is the problem 306c54d0edb6 (""usb: hcd: Try MSI interrupts on PCI
devices), as this following patch stops KASAN complaining for me:
From a3b9e1b405d1efdfee2ee672bbf7dc1c7de62d66 Mon Sep 17 00:00:00 2001
From: John Garry <john.garry@xxxxxxxxxx>
Date: Fri, 14 Aug 2020 18:14:51 +0100
Subject: [PATCH] usb: hcd: Fix use-after-free in usb_hcd_pci_remove()
KASAN reports when CONFIG_DEBUG_TEST_DRIVER_REMOVE is enabled:
==================================================================
[58.095667] BUG: KASAN: use-after-free in usb_hcd_pci_remove+0xbc/0x168
[58.102272] Read of size 8 at addr ffff002a0b6e8120 by task swapper/0/1
[58.108875]
[58.110361] CPU: 2 PID: 1 Comm: swapper/0 Tainted: G
W5.8.0-next-20200813-dirty #31
[58.119396] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI RC0
- V1.16.01 03/15/2019
[58.127910] Call trace:
[58.130351] dump_backtrace+0x0/0x2d0
[58.134005] show_stack+0x18/0x28
[58.137313] dump_stack+0xf4/0x168
[58.140709] print_address_description.constprop.12+0x6c/0x4ec
[58.146532] kasan_report+0x130/0x200
[58.150186] __asan_load8+0x9c/0xd8
[58.153666] usb_hcd_pci_remove+0xbc/0x168
[58.157755] xhci_pci_remove+0xb8/0x108
[58.161583] pci_device_remove+0x6c/0x138
[58.165586] really_probe+0x22c/0x640
[58.169240] driver_probe_device+0x78/0xe8
[58.173328] device_driver_attach+0x9c/0xa8
[58.177504] __driver_attach+0x74/0x120
[58.181331] bus_for_each_dev+0xec/0x160
[58.185245] driver_attach+0x34/0x48
[58.188812] bus_add_driver+0x1b8/0x2c0
[58.192639] driver_register+0xc0/0x1e0
[58.196467] __pci_register_driver+0xb4/0xd0
[58.200729] xhci_pci_init+0x60/0x70
[58.204297] do_one_initcall+0xd4/0x264
[58.208125] kernel_init_freeable+0x270/0x2d8
[58.212475] kernel_init+0x14/0x124
[58.215955] ret_from_fork+0x10/0x34
[58.216996] hub 1-1:1.0: USB hub found
[58.219519]
[58.219523] Allocated by task 13:
[58.219528] kasan_save_stack+0x28/0x58
[58.219538] __kasan_kmalloc.isra.6+0xcc/0xf0
[58.236219] kasan_kmalloc+0x10/0x20
[58.239786] __kmalloc+0x194/0x290
[58.243181] __usb_create_hcd+0x48/0x3a8
[58.247095] usb_create_hcd+0x1c/0x28
[58.250748] usb_hcd_pci_probe+0xa0/0x548
[58.254749] xhci_pci_probe+0x54/0x360
[58.258488] local_pci_probe+0x78/0xf8
[58.262230] work_for_cpu_fn+0x30/0x50
[58.265971] process_one_work+0x424/0x698
[58.269972] worker_thread+0x438/0x6d0
[58.273713] kthread+0x224/0x230
[58.276933] ret_from_fork+0x10/0x34
[58.280497]
[58.281978] Freed by task 1:
[58.284851] kasan_save_stack+0x28/0x58
[58.288677] kasan_set_track+0x28/0x40
[58.292418] kasan_set_free_info+0x24/0x48
[58.296505] __kasan_slab_free+0x104/0x188
[58.300593] kasan_slab_free+0x14/0x20
[58.304333] slab_free_freelist_hook+0x8c/0x190
[58.308855] kfree+0x2cc/0x400
[58.311901] usb_put_hcd+0xc0/0x110
[58.315381] usb_hcd_pci_remove+0xb4/0x168
[58.317397] hub 1-1:1.0: 4 ports detected
[58.319468] xhci_pci_remove+0xb8/0x108
[58.319473] pci_device_remove+0x6c/0x138
[58.319480] really_probe+0x22c/0x640
[58.334943] driver_probe_device+0x78/0xe8
[58.339031] device_driver_attach+0x9c/0xa8
[58.343205] __driver_attach+0x74/0x120
[58.347033] bus_for_each_dev+0xec/0x160
[58.350947] driver_attach+0x34/0x48
[58.354513] bus_add_driver+0x1b8/0x2c0
[58.358340] driver_register+0xc0/0x1e0
[58.362168] __pci_register_driver+0xb4/0xd0
[58.366429] xhci_pci_init+0x60/0x70
[58.369995] do_one_initcall+0xd4/0x264
[58.373823] kernel_init_freeable+0x270/0x2d8
[58.378171] kernel_init+0x14/0x124
[58.381651] ret_from_fork+0x10/0x34
[58.385215]
[58.386699] The buggy address belongs to the object at ffff002a0b6e8000
[58.386699] which belongs to the cache kmalloc-8k of size 8192
[58.399207] The buggy address is located 288 bytes inside of
[58.399207] 8192-byte region [ffff002a0b6e8000, ffff002a0b6ea000)
[58.411019] The buggy address belongs to the page:
[58.415803] page:0000000060c9fcec refcount:1 mapcount:0
mapping:0000000000000000 index:0x0 pfn:0x2a0b6e8
[58.425272] head:0000000060c9fcec order:3 compound_mapcount:0
compound_pincount:0
[58.432746] flags: 0x2ffff00000010200(slab|head)
[58.437357] raw: 2ffff00000010200 dead000000000100 dead000000000122
ffff002a53c0f300
[58.445092] raw: 0000000000000000 0000000080020002 00000001ffffffff
0000000000000000
[58.452824] page dumped because: kasan: bad access detected
[58.458385]
[58.459867] Memory state around the buggy address:
[58.464649] ffff002a0b6e8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb
[58.471862] ffff002a0b6e8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb
[58.479074] >ffff002a0b6e8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb
[58.486284] ^
[58.490545] ffff002a0b6e8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb
[58.497758] ffff002a0b6e8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb
[58.504968]
==================================================================
Fix by relocating the usb_put_hcd() call until after the
hcd->driver->flags check.
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index 4dc443aaef5c..44a8d3644973 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -346,9 +346,9 @@ void usb_hcd_pci_remove(struct pci_dev *dev)
dev_set_drvdata(&dev->dev, NULL);
up_read(&companions_rwsem);
}
- usb_put_hcd(hcd);
if ((hcd->driver->flags & HCD_MASK) < HCD_USB3)
pci_free_irq_vectors(dev);
+ usb_put_hcd(hcd);
pci_disable_device(dev);
}
EXPORT_SYMBOL_GPL(usb_hcd_pci_remove);
---->8-----------
@Andy, Apologies if I'm off the mark!
Thanks,
John
