| Message ID | 1571148451-91114-1-git-send-email-john.garry@huawei.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | ACPI / CPPC: Set pcc_data[pcc_ss_id] to NULL in acpi_cppc_processor_exit() | expand |
On Tue, Oct 15, 2019 at 4:10 PM John Garry <john.garry@huawei.com> wrote: > > When enabling KASAN and DEBUG_TEST_DRIVER_REMOVE, I find this KASAN > warning: > > [ 20.872057] BUG: KASAN: use-after-free in pcc_data_alloc+0x40/0xb8 > [ 20.878226] Read of size 4 at addr ffff00236cdeb684 by task swapper/0/1 > [ 20.884826] > [ 20.886309] CPU: 19 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc1-00009-ge7f7df3db5bf-dirty #289 > [ 20.894994] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI RC0 - V1.16.01 03/15/2019 > [ 20.903505] Call trace: > [ 20.905942] dump_backtrace+0x0/0x200 > [ 20.909593] show_stack+0x14/0x20 > [ 20.912899] dump_stack+0xd4/0x130 > [ 20.916291] print_address_description.isra.9+0x6c/0x3b8 > [ 20.921592] __kasan_report+0x12c/0x23c > [ 20.925417] kasan_report+0xc/0x18 > [ 20.928808] __asan_load4+0x94/0xb8 > [ 20.932286] pcc_data_alloc+0x40/0xb8 > [ 20.935938] acpi_cppc_processor_probe+0x4e8/0xb08 > [ 20.940717] __acpi_processor_start+0x48/0xb0 > [ 20.945062] acpi_processor_start+0x40/0x60 > [ 20.949235] really_probe+0x118/0x548 > [ 20.952887] driver_probe_device+0x7c/0x148 > [ 20.957059] device_driver_attach+0x94/0xa0 > [ 20.961231] __driver_attach+0xa4/0x110 > [ 20.965055] bus_for_each_dev+0xe8/0x158 > [ 20.968966] driver_attach+0x30/0x40 > [ 20.972531] bus_add_driver+0x234/0x2f0 > [ 20.976356] driver_register+0xbc/0x1d0 > [ 20.980182] acpi_processor_driver_init+0x40/0xe4 > [ 20.984875] do_one_initcall+0xb4/0x254 > [ 20.988700] kernel_init_freeable+0x24c/0x2f8 > [ 20.993047] kernel_init+0x10/0x118 > [ 20.996524] ret_from_fork+0x10/0x18 > [ 21.000087] > [ 21.001567] Allocated by task 1: > [ 21.004785] save_stack+0x28/0xc8 > [ 21.008089] __kasan_kmalloc.isra.9+0xbc/0xd8 > [ 21.012435] kasan_kmalloc+0xc/0x18 > [ 21.015913] pcc_data_alloc+0x94/0xb8 > [ 21.019564] acpi_cppc_processor_probe+0x4e8/0xb08 > [ 21.024343] __acpi_processor_start+0x48/0xb0 > [ 21.028689] acpi_processor_start+0x40/0x60 > [ 21.032860] really_probe+0x118/0x548 > [ 21.036512] driver_probe_device+0x7c/0x148 > [ 21.040684] device_driver_attach+0x94/0xa0 > [ 21.044855] __driver_attach+0xa4/0x110 > [ 21.048680] bus_for_each_dev+0xe8/0x158 > [ 21.052591] driver_attach+0x30/0x40 > [ 21.056155] bus_add_driver+0x234/0x2f0 > [ 21.059980] driver_register+0xbc/0x1d0 > [ 21.063805] acpi_processor_driver_init+0x40/0xe4 > [ 21.068497] do_one_initcall+0xb4/0x254 > [ 21.072322] kernel_init_freeable+0x24c/0x2f8 > [ 21.076667] kernel_init+0x10/0x118 > [ 21.080144] ret_from_fork+0x10/0x18 > [ 21.083707] > [ 21.085186] Freed by task 1: > [ 21.088056] save_stack+0x28/0xc8 > [ 21.091360] __kasan_slab_free+0x118/0x180 > [ 21.095445] kasan_slab_free+0x10/0x18 > [ 21.099183] kfree+0x80/0x268 > [ 21.102139] acpi_cppc_processor_exit+0x1a8/0x1b8 > [ 21.106832] acpi_processor_stop+0x70/0x80 > [ 21.110917] really_probe+0x174/0x548 > [ 21.114568] driver_probe_device+0x7c/0x148 > [ 21.118740] device_driver_attach+0x94/0xa0 > [ 21.122912] __driver_attach+0xa4/0x110 > [ 21.126736] bus_for_each_dev+0xe8/0x158 > [ 21.130648] driver_attach+0x30/0x40 > [ 21.134212] bus_add_driver+0x234/0x2f0 > [ 21.0x10/0x18 > [ 21.161764] > [ 21.163244] The buggy address belongs to the object at ffff00236cdeb600 > [ 21.163244] which belongs to the cache kmalloc-256 of size 256 > [ 21.175750] The buggy address is located 132 bytes inside of > [ 21.175750] 256-byte region [ffff00236cdeb600, ffff00236cdeb700) > [ 21.187473] The buggy address belongs to the page: > [ 21.192254] page:fffffe008d937a00 refcount:1 mapcount:0 mapping:ffff002370c0fa00 index:0x0 compound_mapcount: 0 > [ 21.202331] flags: 0x1ffff00000010200(slab|head) > [ 21.206940] raw: 1ffff00000010200 dead000000000100 dead000000000122 ffff002370c0fa00 > [ 21.214671] raw: 0000000000000000 00000000802a002a 00000001ffffffff 0000000000000000 > [ 21.222400] page dumped because: kasan: bad access detected > [ 21.227959] > [ 21.229438] Memory state around the buggy address: > [ 21.234218] ffff00236cdeb580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > [ 21.241427] ffff00236cdeb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 21.248637] >ffff00236cdeb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 21.255845] ^ > [ 21.259062] ffff00236cdeb700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > [ 21.266272] ffff00236cdeb780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > [ 21.273480] ================================================================== > > It seems that global pcc_data[pcc_ss_id] can be freed in > acpi_cppc_processor_exit(), but we may later reference this value, so > NULLify it when freed. > > Also remove the useless setting of data "pcc_channel_acquired", which > we're about to free. > > Signed-off-by: John Garry <john.garry@huawei.com> > > diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c > index 3b2525908dd8..a1a858ad4d18 100644 > --- a/drivers/acpi/cppc_acpi.c > +++ b/drivers/acpi/cppc_acpi.c > @@ -905,8 +905,8 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr) > pcc_data[pcc_ss_id]->refcount--; > if (!pcc_data[pcc_ss_id]->refcount) { > pcc_mbox_free_channel(pcc_data[pcc_ss_id]->pcc_channel); > - pcc_data[pcc_ss_id]->pcc_channel_acquired = 0; > kfree(pcc_data[pcc_ss_id]); > + pcc_data[pcc_ss_id] = NULL; > } > } > } > -- Applied as a fix for 5.4, thanks!
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 3b2525908dd8..a1a858ad4d18 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -905,8 +905,8 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr) pcc_data[pcc_ss_id]->refcount--; if (!pcc_data[pcc_ss_id]->refcount) { pcc_mbox_free_channel(pcc_data[pcc_ss_id]->pcc_channel); - pcc_data[pcc_ss_id]->pcc_channel_acquired = 0; kfree(pcc_data[pcc_ss_id]); + pcc_data[pcc_ss_id] = NULL; } } }
When enabling KASAN and DEBUG_TEST_DRIVER_REMOVE, I find this KASAN warning: [ 20.872057] BUG: KASAN: use-after-free in pcc_data_alloc+0x40/0xb8 [ 20.878226] Read of size 4 at addr ffff00236cdeb684 by task swapper/0/1 [ 20.884826] [ 20.886309] CPU: 19 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc1-00009-ge7f7df3db5bf-dirty #289 [ 20.894994] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI RC0 - V1.16.01 03/15/2019 [ 20.903505] Call trace: [ 20.905942] dump_backtrace+0x0/0x200 [ 20.909593] show_stack+0x14/0x20 [ 20.912899] dump_stack+0xd4/0x130 [ 20.916291] print_address_description.isra.9+0x6c/0x3b8 [ 20.921592] __kasan_report+0x12c/0x23c [ 20.925417] kasan_report+0xc/0x18 [ 20.928808] __asan_load4+0x94/0xb8 [ 20.932286] pcc_data_alloc+0x40/0xb8 [ 20.935938] acpi_cppc_processor_probe+0x4e8/0xb08 [ 20.940717] __acpi_processor_start+0x48/0xb0 [ 20.945062] acpi_processor_start+0x40/0x60 [ 20.949235] really_probe+0x118/0x548 [ 20.952887] driver_probe_device+0x7c/0x148 [ 20.957059] device_driver_attach+0x94/0xa0 [ 20.961231] __driver_attach+0xa4/0x110 [ 20.965055] bus_for_each_dev+0xe8/0x158 [ 20.968966] driver_attach+0x30/0x40 [ 20.972531] bus_add_driver+0x234/0x2f0 [ 20.976356] driver_register+0xbc/0x1d0 [ 20.980182] acpi_processor_driver_init+0x40/0xe4 [ 20.984875] do_one_initcall+0xb4/0x254 [ 20.988700] kernel_init_freeable+0x24c/0x2f8 [ 20.993047] kernel_init+0x10/0x118 [ 20.996524] ret_from_fork+0x10/0x18 [ 21.000087] [ 21.001567] Allocated by task 1: [ 21.004785] save_stack+0x28/0xc8 [ 21.008089] __kasan_kmalloc.isra.9+0xbc/0xd8 [ 21.012435] kasan_kmalloc+0xc/0x18 [ 21.015913] pcc_data_alloc+0x94/0xb8 [ 21.019564] acpi_cppc_processor_probe+0x4e8/0xb08 [ 21.024343] __acpi_processor_start+0x48/0xb0 [ 21.028689] acpi_processor_start+0x40/0x60 [ 21.032860] really_probe+0x118/0x548 [ 21.036512] driver_probe_device+0x7c/0x148 [ 21.040684] device_driver_attach+0x94/0xa0 [ 21.044855] __driver_attach+0xa4/0x110 [ 21.048680] bus_for_each_dev+0xe8/0x158 [ 21.052591] driver_attach+0x30/0x40 [ 21.056155] bus_add_driver+0x234/0x2f0 [ 21.059980] driver_register+0xbc/0x1d0 [ 21.063805] acpi_processor_driver_init+0x40/0xe4 [ 21.068497] do_one_initcall+0xb4/0x254 [ 21.072322] kernel_init_freeable+0x24c/0x2f8 [ 21.076667] kernel_init+0x10/0x118 [ 21.080144] ret_from_fork+0x10/0x18 [ 21.083707] [ 21.085186] Freed by task 1: [ 21.088056] save_stack+0x28/0xc8 [ 21.091360] __kasan_slab_free+0x118/0x180 [ 21.095445] kasan_slab_free+0x10/0x18 [ 21.099183] kfree+0x80/0x268 [ 21.102139] acpi_cppc_processor_exit+0x1a8/0x1b8 [ 21.106832] acpi_processor_stop+0x70/0x80 [ 21.110917] really_probe+0x174/0x548 [ 21.114568] driver_probe_device+0x7c/0x148 [ 21.118740] device_driver_attach+0x94/0xa0 [ 21.122912] __driver_attach+0xa4/0x110 [ 21.126736] bus_for_each_dev+0xe8/0x158 [ 21.130648] driver_attach+0x30/0x40 [ 21.134212] bus_add_driver+0x234/0x2f0 [ 21.0x10/0x18 [ 21.161764] [ 21.163244] The buggy address belongs to the object at ffff00236cdeb600 [ 21.163244] which belongs to the cache kmalloc-256 of size 256 [ 21.175750] The buggy address is located 132 bytes inside of [ 21.175750] 256-byte region [ffff00236cdeb600, ffff00236cdeb700) [ 21.187473] The buggy address belongs to the page: [ 21.192254] page:fffffe008d937a00 refcount:1 mapcount:0 mapping:ffff002370c0fa00 index:0x0 compound_mapcount: 0 [ 21.202331] flags: 0x1ffff00000010200(slab|head) [ 21.206940] raw: 1ffff00000010200 dead000000000100 dead000000000122 ffff002370c0fa00 [ 21.214671] raw: 0000000000000000 00000000802a002a 00000001ffffffff 0000000000000000 [ 21.222400] page dumped because: kasan: bad access detected [ 21.227959] [ 21.229438] Memory state around the buggy address: [ 21.234218] ffff00236cdeb580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 21.241427] ffff00236cdeb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.248637] >ffff00236cdeb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.255845] ^ [ 21.259062] ffff00236cdeb700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 21.266272] ffff00236cdeb780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.273480] ================================================================== It seems that global pcc_data[pcc_ss_id] can be freed in acpi_cppc_processor_exit(), but we may later reference this value, so NULLify it when freed. Also remove the useless setting of data "pcc_channel_acquired", which we're about to free. Signed-off-by: John Garry <john.garry@huawei.com>