Hello,
syzbot has tested the proposed patch but the reproducer still triggered
crash:
KASAN: use-after-free Read in si470x_int_in_callback
radio-si470x 4-1:0.0: non-zero urb status (-71)
==================================================================
BUG: KASAN: use-after-free in si470x_int_in_callback.cold+0x27/0xbe
drivers/media/radio/si470x/radio-si470x-usb.c:378
Read of size 8 at addr ffff8881d2fceab0 by task kworker/0:2/2107
CPU: 0 PID: 2107 Comm: kworker/0:2 Not tainted 5.4.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xca/0x13e lib/dump_stack.c:113
print_address_description.constprop.0+0x36/0x50 mm/kasan/report.c:374
__kasan_report.cold+0x1a/0x33 mm/kasan/report.c:506
kasan_report+0xe/0x20 mm/kasan/common.c:634
si470x_int_in_callback.cold+0x27/0xbe
drivers/media/radio/si470x/radio-si470x-usb.c:378
__usb_hcd_giveback_urb+0x1f2/0x470 drivers/usb/core/hcd.c:1654
usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1719
dummy_timer+0x120f/0x2fa2 drivers/usb/gadget/udc/dummy_hcd.c:1966
call_timer_fn+0x179/0x650 kernel/time/timer.c:1404
expire_timers kernel/time/timer.c:1449 [inline]
__run_timers kernel/time/timer.c:1773 [inline]
__run_timers kernel/time/timer.c:1740 [inline]
run_timer_softirq+0x5e3/0x1490 kernel/time/timer.c:1786
__do_softirq+0x221/0x912 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x178/0x1a0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:536 [inline]
smp_apic_timer_interrupt+0x12f/0x500 arch/x86/kernel/apic/apic.c:1137
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
</IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:85 [inline]
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1751 [inline]
RIP: 0010:vprintk_emit+0x3cd/0x3e0 kernel/printk/printk.c:1995
Code: 00 83 fb ff 75 d6 e9 db fc ff ff e8 fd 7a 15 00 e8 78 a7 1a 00 41 56
9d e9 b1 fd ff ff e8 eb 7a 15 00 e8 66 a7 1a 00 41 56 9d <e9> 2a ff ff ff
0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 55 48 89
RSP: 0018:ffff8881cb01f238 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000007 RBX: 0000000000000200 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffff8881cbfa08f0 RDI: ffff8881cbfa084c
RBP: ffff8881cb01f280 R08: ffff8881cbfa0000 R09: fffffbfff11b23ae
R10: fffffbfff11b23ad R11: ffffffff88d91d6f R12: 0000000000000034
R13: ffff8881da24e000 R14: 0000000000000293 R15: 0000000000000000
vprintk_func+0x75/0x113 kernel/printk/printk_safe.c:386
printk+0xba/0xed kernel/printk/printk.c:2056
really_probe.cold+0x69/0x1de drivers/base/dd.c:628
driver_probe_device+0x104/0x210 drivers/base/dd.c:721
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x360 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0xae6/0x16f0 drivers/base/core.c:2201
usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
really_probe+0x281/0x6d0 drivers/base/dd.c:548
driver_probe_device+0x104/0x210 drivers/base/dd.c:721
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x360 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0xae6/0x16f0 drivers/base/core.c:2201
usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536
hub_port_connect drivers/usb/core/hub.c:5183 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5323 [inline]
port_event drivers/usb/core/hub.c:5469 [inline]
hub_event+0x1dd0/0x37e0 drivers/usb/core/hub.c:5551
process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
worker_thread+0x96/0xe20 kernel/workqueue.c:2415
kthread+0x318/0x420 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Allocated by task 2107:
save_stack+0x1b/0x80 mm/kasan/common.c:69
set_track mm/kasan/common.c:77 [inline]
__kasan_kmalloc mm/kasan/common.c:510 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:483
kmalloc include/linux/slab.h:556 [inline]
kzalloc include/linux/slab.h:690 [inline]
si470x_usb_driver_probe+0x51/0xf50
drivers/media/radio/si470x/radio-si470x-usb.c:573
usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
really_probe+0x281/0x6d0 drivers/base/dd.c:548
driver_probe_device+0x104/0x210 drivers/base/dd.c:721
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x360 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0xae6/0x16f0 drivers/base/core.c:2201
usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
really_probe+0x281/0x6d0 drivers/base/dd.c:548
driver_probe_device+0x104/0x210 drivers/base/dd.c:721
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x360 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0xae6/0x16f0 drivers/base/core.c:2201
usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536
hub_port_connect drivers/usb/core/hub.c:5183 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5323 [inline]
port_event drivers/usb/core/hub.c:5469 [inline]
hub_event+0x1dd0/0x37e0 drivers/usb/core/hub.c:5551
process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
worker_thread+0x96/0xe20 kernel/workqueue.c:2415
kthread+0x318/0x420 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Freed by task 2107:
save_stack+0x1b/0x80 mm/kasan/common.c:69
set_track mm/kasan/common.c:77 [inline]
kasan_set_free_info mm/kasan/common.c:332 [inline]
__kasan_slab_free+0x130/0x180 mm/kasan/common.c:471
slab_free_hook mm/slub.c:1424 [inline]
slab_free_freelist_hook mm/slub.c:1475 [inline]
slab_free mm/slub.c:3018 [inline]
kfree+0xe4/0x320 mm/slub.c:3967
si470x_usb_driver_probe+0xb27/0xf50
drivers/media/radio/si470x/radio-si470x-usb.c:766
usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
really_probe+0x281/0x6d0 drivers/base/dd.c:548
driver_probe_device+0x104/0x210 drivers/base/dd.c:721
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x360 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0xae6/0x16f0 drivers/base/core.c:2201
usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
really_probe+0x281/0x6d0 drivers/base/dd.c:548
driver_probe_device+0x104/0x210 drivers/base/dd.c:721
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x360 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0xae6/0x16f0 drivers/base/core.c:2201
usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536
hub_port_connect drivers/usb/core/hub.c:5183 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5323 [inline]
port_event drivers/usb/core/hub.c:5469 [inline]
hub_event+0x1dd0/0x37e0 drivers/usb/core/hub.c:5551
process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
worker_thread+0x96/0xe20 kernel/workqueue.c:2415
kthread+0x318/0x420 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
The buggy address belongs to the object at ffff8881d2fce000
which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 2736 bytes inside of
4096-byte region [ffff8881d2fce000, ffff8881d2fcf000)
The buggy address belongs to the page:
page:ffffea00074bf200 refcount:1 mapcount:0 mapping:ffff8881da00c280
index:0x0 compound_mapcount: 0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 dead000000000100 dead000000000122 ffff8881da00c280
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8881d2fce980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881d2fcea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881d2fcea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881d2fceb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881d2fceb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Tested on:
commit: 22be26f7 usb-fuzzer: main usb gadget fuzzer driver
git tree: https://github.com/google/kasan.git
console output: https://syzkaller.appspot.com/x/log.txt?x=149ed686e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=387eccb7ac68ec5
dashboard link: https://syzkaller.appspot.com/bug?extid=9ca7a12fd736d93e0232
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
patch: https://syzkaller.appspot.com/x/patch.diff?x=1508a25ae00000
