| Message ID | 20200506155312.1777481-1-suzuki.poulose@arm.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 3f4943d422c5febbb3c764670011a00eb2a86238 |
| Headers | show |
| Series | coresight: etm4x: Fix use-after-free of per-cpu etm drvdata | expand |
On Wed, May 06, 2020 at 04:53:12PM +0100, Suzuki K Poulose wrote: > etm probe could be deferred due to the dependency in the trace > path chain and may be retried. We need to clear the per-cpu > etmdrvdata entry for the etm in case of a failure to avoid > use-after-free cases as reported below: > > KASAN use-after-free bug in etm4_cpu_pm_notify(): > > [ 8.574566] coresight etm0: CPU0: ETM v4.2 initialized > [ 8.581920] BUG: KASAN: use-after-free in etm4_cpu_pm_notify+0x580/0x2024 > [ 8.581925] Read of size 8 at addr ffffff813304f8c8 by task swapper/3/0 > [ 8.581927] > [ 8.581934] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G S W 5.4.28 #314 > [ 8.587775] coresight etm1: CPU1: ETM v4.2 initialized > [ 8.594195] Call trace: > [ 8.594205] dump_backtrace+0x0/0x188 > [ 8.594209] show_stack+0x20/0x2c > [ 8.594216] dump_stack+0xdc/0x144 > [ 8.594227] print_address_description+0x3c/0x494 > [ 8.594232] __kasan_report+0x144/0x168 > [ 8.601598] coresight etm2: CPU2: ETM v4.2 initialized > [ 8.602563] kasan_report+0x10/0x18 > [ 8.602568] check_memory_region+0x1a4/0x1b4 > [ 8.602572] __kasan_check_read+0x18/0x24 > [ 8.602577] etm4_cpu_pm_notify+0x580/0x2024 > [ 8.665945] notifier_call_chain+0x5c/0x90 > [ 8.670166] __atomic_notifier_call_chain+0x90/0xf8 > [ 8.675182] cpu_pm_notify+0x40/0x6c > [ 8.678858] cpu_pm_enter+0x38/0x80 > [ 8.682451] psci_enter_idle_state+0x34/0x70 > [ 8.686844] cpuidle_enter_state+0xb8/0x20c > [ 8.691143] cpuidle_enter+0x38/0x4c > [ 8.694820] call_cpuidle+0x3c/0x68 > [ 8.698408] do_idle+0x1a0/0x280 > [ 8.701729] cpu_startup_entry+0x24/0x28 > [ 8.705768] secondary_start_kernel+0x15c/0x170 > [ 8.710423] > [ 8.711972] Allocated by task 242: > [ 8.715473] __kasan_kmalloc+0xf0/0x1ac > [ 8.719426] kasan_slab_alloc+0x14/0x1c > [ 8.723375] __kmalloc_track_caller+0x23c/0x388 > [ 8.728040] devm_kmalloc+0x38/0x94 > [ 8.731632] etm4_probe+0x48/0x3c8 > [ 8.735140] amba_probe+0xbc/0x158 > [ 8.738645] really_probe+0x144/0x408 > [ 8.742412] driver_probe_device+0x70/0x140 > [ 8.746716] __device_attach_driver+0x9c/0x110 > [ 8.751287] bus_for_each_drv+0x90/0xd8 > [ 8.755236] __device_attach+0xb4/0x164 > [ 8.759188] device_initial_probe+0x20/0x2c > [ 8.763490] bus_probe_device+0x34/0x94 > [ 8.767436] device_add+0x34c/0x3e0 > [ 8.771029] amba_device_try_add+0x68/0x440 > [ 8.775332] amba_deferred_retry_func+0x48/0xc8 > [ 8.779997] process_one_work+0x344/0x648 > [ 8.784127] worker_thread+0x2ac/0x47c > [ 8.787987] kthread+0x128/0x138 > [ 8.791313] ret_from_fork+0x10/0x18 > [ 8.794993] > [ 8.796532] Freed by task 242: > [ 8.799684] __kasan_slab_free+0x15c/0x22c > [ 8.803897] kasan_slab_free+0x10/0x1c > [ 8.807761] kfree+0x25c/0x4bc > [ 8.810913] release_nodes+0x240/0x2b0 > [ 8.814767] devres_release_all+0x3c/0x54 > [ 8.818887] really_probe+0x178/0x408 > [ 8.822661] driver_probe_device+0x70/0x140 > [ 8.826963] __device_attach_driver+0x9c/0x110 > [ 8.831539] bus_for_each_drv+0x90/0xd8 > [ 8.835487] __device_attach+0xb4/0x164 > [ 8.839431] device_initial_probe+0x20/0x2c > [ 8.843732] bus_probe_device+0x34/0x94 > [ 8.847678] device_add+0x34c/0x3e0 > [ 8.851274] amba_device_try_add+0x68/0x440 > [ 8.855576] amba_deferred_retry_func+0x48/0xc8 > [ 8.860240] process_one_work+0x344/0x648 > [ 8.864366] worker_thread+0x2ac/0x47c > [ 8.868228] kthread+0x128/0x138 > [ 8.871557] ret_from_fork+0x10/0x18 > [ 8.875231] > [ 8.876782] The buggy address belongs to the object at ffffff813304f800 > [ 8.876782] which belongs to the cache kmalloc-1k of size 1024 > [ 8.889632] The buggy address is located 200 bytes inside of > [ 8.889632] 1024-byte region [ffffff813304f800, ffffff813304fc00) > [ 8.901761] The buggy address belongs to the page: > [ 8.906695] page:ffffffff04ac1200 refcount:1 mapcount:0 mapping:ffffff8146c03800 index:0x0 compound_mapcount: 0 > [ 8.917047] flags: 0x4000000000010200(slab|head) > [ 8.921799] raw: 4000000000010200 dead000000000100 dead000000000122 ffffff8146c03800 > [ 8.929753] raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 > [ 8.937703] page dumped because: kasan: bad access detected > [ 8.943433] > [ 8.944974] Memory state around the buggy address: > [ 8.949903] ffffff813304f780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > [ 8.957320] ffffff813304f800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 8.964742] >ffffff813304f880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 8.972157] ^ > [ 8.977886] ffffff813304f900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 8.985298] ffffff813304f980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 8.992713] ================================================================== > > Fixes: f188b5e76aae9 ( "coresight: etm4x: Save/restore state across CPU low power states ") > Reported-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> > Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> > Cc: Mathieu Poirier <mathieu.poirier@linaro.org> > Cc: Mike Leach <mike.leach@linaro.org> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > --- > drivers/hwtracing/coresight/coresight-etm4x.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c > index 0b2c7c7efacb..d7e19d91ff17 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x.c > @@ -1516,6 +1516,7 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) > return 0; > > err_arch_supported: > + etmdrvdata[drvdata->cpu] = NULL; KASAN is once again proving its usefulness - finding a code path like that is impossible by just looking at the code. Applied - thanks, Mathieu > if (--etm4_count == 0) { > etm4_cpu_pm_unregister(); > > -- > 2.24.1 >
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index 0b2c7c7efacb..d7e19d91ff17 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -1516,6 +1516,7 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) return 0; err_arch_supported: + etmdrvdata[drvdata->cpu] = NULL; if (--etm4_count == 0) { etm4_cpu_pm_unregister();