mirror of https://github.com/torvalds/linux.git
f8b4687151
The original code relies on cancel_delayed_work() in otx2_ptp_destroy(),
which does not ensure that the delayed work item synctstamp_work has fully
completed if it was already running. This leads to use-after-free scenarios
where otx2_ptp is deallocated by otx2_ptp_destroy(), while synctstamp_work
remains active and attempts to dereference otx2_ptp in otx2_sync_tstamp().
Furthermore, the synctstamp_work is cyclic, the likelihood of triggering
the bug is nonnegligible.
A typical race condition is illustrated below:
CPU 0 (cleanup) | CPU 1 (delayed work callback)
otx2_remove() |
otx2_ptp_destroy() | otx2_sync_tstamp()
cancel_delayed_work() |
kfree(ptp) |
| ptp = container_of(...); //UAF
| ptp-> //UAF
This is confirmed by a KASAN report:
BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x7d7/0x8c0
Write of size 8 at addr ffff88800aa09a18 by task bash/136
...
Call Trace:
<IRQ>
dump_stack_lvl+0x55/0x70
print_report+0xcf/0x610
? __run_timer_base.part.0+0x7d7/0x8c0
kasan_report+0xb8/0xf0
? __run_timer_base.part.0+0x7d7/0x8c0
__run_timer_base.part.0+0x7d7/0x8c0
? __pfx___run_timer_base.part.0+0x10/0x10
? __pfx_read_tsc+0x10/0x10
? ktime_get+0x60/0x140
? lapic_next_event+0x11/0x20
? clockevents_program_event+0x1d4/0x2a0
run_timer_softirq+0xd1/0x190
handle_softirqs+0x16a/0x550
irq_exit_rcu+0xaf/0xe0
sysvec_apic_timer_interrupt+0x70/0x80
</IRQ>
...
Allocated by task 1:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x7f/0x90
otx2_ptp_init+0xb1/0x860
otx2_probe+0x4eb/0xc30
local_pci_probe+0xdc/0x190
pci_device_probe+0x2fe/0x470
really_probe+0x1ca/0x5c0
__driver_probe_device+0x248/0x310
driver_probe_device+0x44/0x120
__driver_attach+0xd2/0x310
bus_for_each_dev+0xed/0x170
bus_add_driver+0x208/0x500
driver_register+0x132/0x460
do_one_initcall+0x89/0x300
kernel_init_freeable+0x40d/0x720
kernel_init+0x1a/0x150
ret_from_fork+0x10c/0x1a0
ret_from_fork_asm+0x1a/0x30
Freed by task 136:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3a/0x60
__kasan_slab_free+0x3f/0x50
kfree+0x137/0x370
otx2_ptp_destroy+0x38/0x80
otx2_remove+0x10d/0x4c0
pci_device_remove+0xa6/0x1d0
device_release_driver_internal+0xf8/0x210
pci_stop_bus_device+0x105/0x150
pci_stop_and_remove_bus_device_locked+0x15/0x30
remove_store+0xcc/0xe0
kernfs_fop_write_iter+0x2c3/0x440
vfs_write+0x871/0xd70
ksys_write+0xee/0x1c0
do_syscall_64+0xac/0x280
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the delayed work item is properly canceled before the otx2_ptp is
deallocated.
This bug was initially identified through static analysis. To reproduce
and test it, I simulated the OcteonTX2 PCI device in QEMU and introduced
artificial delays within the otx2_sync_tstamp() function to increase the
likelihood of triggering the bug.
Fixes:
|
||
|---|---|---|
| .. | ||
| 3com | ||
| 8390 | ||
| actions | ||
| adaptec | ||
| adi | ||
| aeroflex | ||
| agere | ||
| airoha | ||
| alacritech | ||
| allwinner | ||
| alteon | ||
| altera | ||
| amazon | ||
| amd | ||
| apm | ||
| apple | ||
| aquantia | ||
| arc | ||
| asix | ||
| atheros | ||
| broadcom | ||
| brocade | ||
| cadence | ||
| calxeda | ||
| cavium | ||
| chelsio | ||
| cirrus | ||
| cisco | ||
| cortina | ||
| davicom | ||
| dec | ||
| dlink | ||
| emulex | ||
| engleder | ||
| ezchip | ||
| faraday | ||
| freescale | ||
| fujitsu | ||
| fungible | ||
| hisilicon | ||
| huawei | ||
| i825xx | ||
| ibm | ||
| intel | ||
| litex | ||
| marvell | ||
| mediatek | ||
| mellanox | ||
| meta | ||
| micrel | ||
| microchip | ||
| microsoft | ||
| moxa | ||
| mscc | ||
| myricom | ||
| natsemi | ||
| neterion | ||
| netronome | ||
| ni | ||
| nvidia | ||
| nxp | ||
| oki-semi | ||
| packetengines | ||
| pasemi | ||
| pensando | ||
| qlogic | ||
| qualcomm | ||
| rdc | ||
| realtek | ||
| renesas | ||
| rocker | ||
| samsung | ||
| seeq | ||
| sfc | ||
| sgi | ||
| silan | ||
| sis | ||
| smsc | ||
| socionext | ||
| stmicro | ||
| sun | ||
| sunplus | ||
| synopsys | ||
| tehuti | ||
| ti | ||
| toshiba | ||
| tundra | ||
| vertexcom | ||
| via | ||
| wangxun | ||
| wiznet | ||
| xilinx | ||
| xircom | ||
| xscale | ||
| Kconfig | ||
| Makefile | ||
| dnet.c | ||
| dnet.h | ||
| ec_bhf.c | ||
| ethoc.c | ||
| fealnx.c | ||
| jme.c | ||
| jme.h | ||
| korina.c | ||
| lantiq_etop.c | ||
| lantiq_xrx200.c | ||
| oa_tc6.c | ||