Re: 4.11-rc1 acpi stomping ext4 slabs

From: Rafael J. Wysocki
Date: Mon Mar 06 2017 - 17:48:12 EST

On Mon, Mar 6, 2017 at 9:31 PM, Nikolay Borisov
<n.borisov.lkml@xxxxxxxxx> wrote:
> Hello,
>
> Booting 4.11-rc1 with kasan enabled and "slub_debug=F" produces the following errors:
>
> [ 7.070797] ==================================================================
> [ 7.071724] BUG: KASAN: slab-out-of-bounds in filldir+0xc3/0x160 at addr ffff88006bc2b0ae
> [ 7.071724] Read of size 20 by task systemd/1
> [ 7.071724] CPU: 1 PID: 1 Comm: systemd Not tainted 4.11.0-rc1-nbor #150
> [ 7.071724] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
> [ 7.071724] Call Trace:
> [ 7.071724] dump_stack+0x85/0xc9
> [ 7.071724] kasan_object_err+0x2c/0x90
> [ 7.071724] kasan_report+0x285/0x510
> [ 7.071724] check_memory_region+0x137/0x160
> [ 7.071724] kasan_check_read+0x11/0x20
> [ 7.071724] filldir+0xc3/0x160
> [ 7.071724] call_filldir+0x88/0x140
> [ 7.071724] ext4_readdir+0x757/0x920
> [ 7.071724] ? iterate_dir+0x49/0x190
> [ 7.071724] iterate_dir+0x7d/0x190
> [ 7.071724] ? entry_SYSCALL_64_fastpath+0x5/0xc6
> [ 7.071724] SyS_getdents+0xac/0x170
> [ 7.071724] ? filldir64+0x170/0x170
> [ 7.071724] entry_SYSCALL_64_fastpath+0x23/0xc6
> [ 7.071724] RIP: 0033:0x7fa37ca2dd3b
> [ 7.071724] RSP: 002b:00007ffc63daf400 EFLAGS: 00000206 ORIG_RAX: 000000000000004e
> [ 7.071724] RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007fa37ca2dd3b
> [ 7.071724] RDX: 0000000000008000 RSI: 0000560b369e4a10 RDI: 0000000000000004
> [ 7.071724] RBP: 00007fa37cd29b20 R08: 00007fa37cd29bd8 R09: 0000000000000000
> [ 7.071724] R10: 000000000000008f R11: 0000000000000206 R12: 0000000000008041
> [ 7.071724] R13: 00007fa37cd29b78 R14: 000000000000270f R15: 00007fa37cd29b78
> [ 7.071724] Object at ffff88006bc2b080, in cache kmalloc-96 size: 96
> [ 7.071724] Allocated:
> [ 7.071724] PID = 1
> [ 7.071724] save_stack_trace+0x1b/0x20
> [ 7.071724] kasan_kmalloc.part.4+0x64/0xf0
> [ 7.071724] kasan_kmalloc+0x85/0xb0
> [ 7.071724] __kmalloc+0x12b/0x320
> [ 7.071724] ext4_htree_store_dirent+0x3e/0x120
> [ 7.071724] htree_dirblock_to_tree+0xb9/0x1a0
> [ 7.071724] ext4_htree_fill_tree+0xa3/0x310
> [ 7.071724] ext4_readdir+0x6a9/0x920
> [ 7.071724] iterate_dir+0x7d/0x190
> [ 7.071724] SyS_getdents+0xac/0x170
> [ 7.071724] entry_SYSCALL_64_fastpath+0x23/0xc6
> [ 7.071724] Freed:
> [ 7.071724] PID = 1
> [ 7.071724] save_stack_trace+0x1b/0x20
> [ 7.071724] kasan_slab_free+0xbe/0x190
> [ 7.071724] kfree+0xff/0x2f0
> [ 7.071724] acpi_ut_evaluate_object+0x18e/0x19d
> [ 7.071724] acpi_ut_execute_STA+0x26/0x53
> [ 7.071724] acpi_ns_get_device_callback+0x73/0x163
> [ 7.071724] acpi_ns_walk_namespace+0xc0/0x17a
> [ 7.071724] acpi_get_devices+0x66/0x7d
> [ 7.071724] pnpacpi_init+0x52/0x74
> [ 7.071724] do_one_initcall+0x51/0x1b0
> [ 7.071724] kernel_init_freeable+0x20a/0x2a1
> [ 7.071724] kernel_init+0xe/0x100
> [ 7.071724] ret_from_fork+0x31/0x40
> [ 7.071724] Memory state around the buggy address:
> [ 7.071724] ffff88006bc2af80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> [ 7.071724] ffff88006bc2b000: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
> [ 7.071724] >ffff88006bc2b080: 00 00 00 00 00 00 00 00 05 fc fc fc fc fc fc fc
> [ 7.071724] ^
> [ 7.071724] ffff88006bc2b100: 00 00 00 00 00 00 00 00 00 04 fc fc fc fc fc fc
> [ 7.071724] ffff88006bc2b180: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
>
> Not killing the VM instantly produces a continuous stream of kasan errors. Most of them
> are identical to the one above, however there was one which was different:
>
> [ 5.846193] ==================================================================
> [ 5.846787] BUG: KASAN: slab-out-of-bounds in filldir+0xc3/0x160 at addr ffff88006c783eae
> [ 5.847177] Read of size 22 by task systemd/1
> [ 5.847177] CPU: 3 PID: 1 Comm: systemd Tainted: G B 4.11.0-rc1-nbor #150
> [ 5.847177] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
> [ 5.847177] Call Trace:
> [ 5.847177] dump_stack+0x85/0xc9
> [ 5.847177] kasan_object_err+0x2c/0x90
> [ 5.847177] kasan_report+0x285/0x510
> [ 5.847177] check_memory_region+0x137/0x160
> [ 5.847177] kasan_check_read+0x11/0x20
> [ 5.847177] filldir+0xc3/0x160
> [ 5.847177] call_filldir+0x88/0x140
> [ 5.847177] ext4_readdir+0x757/0x920
> [ 5.847177] ? iterate_dir+0x49/0x190
> [ 5.847177] iterate_dir+0x7d/0x190
> [ 5.847177] ? entry_SYSCALL_64_fastpath+0x5/0xc6
> [ 5.847177] SyS_getdents+0xac/0x170
> [ 5.847177] ? filldir64+0x170/0x170
> [ 5.847177] entry_SYSCALL_64_fastpath+0x23/0xc6
> [ 5.847177] RIP: 0033:0x7f9dbd4e1d3b
> [ 5.847177] RSP: 002b:00007ffee6b51a60 EFLAGS: 00000206 ORIG_RAX: 000000000000004e
> [ 5.847177] RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007f9dbd4e1d3b
> [ 5.847177] RDX: 0000000000008000 RSI: 000055c046802a10 RDI: 0000000000000004
> [ 5.847177] RBP: 00007f9dbd7ddb20 R08: 00007f9dbd7ddbd8 R09: 0000000000000000
> [ 5.847177] R10: 000000000000008f R11: 0000000000000206 R12: 0000000000008041
> [ 5.847177] R13: 00007f9dbd7ddb78 R14: 000000000000270f R15: 00007f9dbd7ddb78
> [ 5.847177] Object at ffff88006c783e80, in cache kmalloc-96 size: 96
> [ 5.847177] Allocated:
> [ 5.847177] PID = 1
> [ 5.847177] save_stack_trace+0x1b/0x20
> [ 5.847177] kasan_kmalloc.part.4+0x64/0xf0
> [ 5.847177] kasan_kmalloc+0x85/0xb0
> [ 5.847177] __kmalloc+0x12b/0x320
> [ 5.847177] ext4_htree_store_dirent+0x3e/0x120
> [ 5.847177] htree_dirblock_to_tree+0xb9/0x1a0
> [ 5.847177] ext4_htree_fill_tree+0xa3/0x310
> [ 5.847177] ext4_readdir+0x6a9/0x920
> [ 5.847177] iterate_dir+0x7d/0x190
> [ 5.847177] SyS_getdents+0xac/0x170
> [ 5.847177] entry_SYSCALL_64_fastpath+0x23/0xc6
> [ 5.847177] Freed:
> [ 5.847177] PID = 1
> [ 5.847177] save_stack_trace+0x1b/0x20
> [ 5.847177] kasan_slab_free+0xbe/0x190
> [ 5.847177] kfree+0xff/0x2f0
> [ 5.847177] krealloc+0xac/0xc0
> [ 5.847177] create_trace_option_files+0x127/0x270
> [ 5.847177] __update_tracer_options+0x2c/0x40
> [ 5.847177] tracer_init_tracefs+0x1a4/0x1b7
> [ 5.847177] do_one_initcall+0x51/0x1b0
> [ 5.847177] kernel_init_freeable+0x20a/0x2a1
> [ 5.847177] kernel_init+0xe/0x100
> [ 5.847177] ret_from_fork+0x31/0x40
> [ 5.847177] Memory state around the buggy address:
>
> So the free path is different.
>
> On a different boot with slab_debug options omitted e.g. no debugging enabled for SLUB
> I got:
>
> [ 5.586620] ==================================================================
> [ 5.587445] BUG: KASAN: slab-out-of-bounds in filldir+0xc3/0x160 at addr ffff880000141aae
> [ 5.587584] Read of size 20 by task systemd/1
> [ 5.587584] CPU: 0 PID: 1 Comm: systemd Not tainted 4.11.0-rc1-nbor #148
> [ 5.587584] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
> [ 5.587584] Call Trace:
> [ 5.587584] dump_stack+0x85/0xc9
> [ 5.587584] kasan_object_err+0x2c/0x90
> [ 5.587584] kasan_report+0x285/0x510
> [ 5.587584] check_memory_region+0x137/0x160
> [ 5.587584] kasan_check_read+0x11/0x20
> [ 5.587584] filldir+0xc3/0x160
> [ 5.587584] call_filldir+0x88/0x140
> [ 5.587584] ext4_readdir+0x757/0x920
> [ 5.587584] ? iterate_dir+0x49/0x190
> [ 5.587584] iterate_dir+0x7d/0x190
> [ 5.587584] ? entry_SYSCALL_64_fastpath+0x5/0xc6
> [ 5.587584] SyS_getdents+0xac/0x170
> [ 5.587584] ? filldir64+0x170/0x170
> [ 5.587584] entry_SYSCALL_64_fastpath+0x23/0xc6
> [ 5.587584] RIP: 0033:0x7f71af785d3b
> [ 5.587584] RSP: 002b:00007ffeeda83390 EFLAGS: 00000206 ORIG_RAX: 000000000000004e
> [ 5.587584] RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007f71af785d3b
> [ 5.587584] RDX: 0000000000008000 RSI: 0000561e6483ba10 RDI: 0000000000000004
> [ 5.587584] RBP: 00007f71afa81b20 R08: 00007f71afa81bd8 R09: 0000000000000000
> [ 5.587584] R10: 000000000000008f R11: 0000000000000206 R12: 0000000000008041
> [ 5.587584] R13: 00007f71afa81b78 R14: 000000000000270f R15: 00007f71afa81b78
> [ 5.587584] Object at ffff880000141a80, in cache kmalloc-96 size: 96
> [ 5.587584] Allocated:
> [ 5.587584] PID = 1
> [ 5.587584] save_stack_trace+0x1b/0x20
> [ 5.587584] kasan_kmalloc.part.4+0x64/0xf0
> [ 5.587584] kasan_kmalloc+0x85/0xb0
> [ 5.587584] __kmalloc+0x12b/0x320
> [ 5.587584] ext4_htree_store_dirent+0x3e/0x120
> [ 5.587584] htree_dirblock_to_tree+0xb9/0x1a0
> [ 5.587584] ext4_htree_fill_tree+0xa3/0x310
> [ 5.587584] ext4_readdir+0x6a9/0x920
> [ 5.587584] iterate_dir+0x7d/0x190
> [ 5.587584] SyS_getdents+0xac/0x170
> [ 5.587584] entry_SYSCALL_64_fastpath+0x23/0xc6
> [ 5.587584] Freed:
> [ 5.587584] PID = 1
> [ 5.587584] save_stack_trace+0x1b/0x20
> [ 5.587584] kasan_slab_free+0xbe/0x190
> [ 5.587584] kfree+0xff/0x2f0
> [ 5.587584] acpi_evaluate_object+0x26c/0x27e
> [ 5.587584] acpi_evaluate_integer+0x34/0x53
> [ 5.587584] acpi_get_node+0x2b/0x51
> [ 5.587584] pci_acpi_scan_root+0x2e/0x1d0
> [ 5.587584] acpi_pci_root_add+0x264/0x34b
> [ 5.587584] acpi_bus_attach+0xb6/0x15c
> [ 5.587584] acpi_bus_attach+0x123/0x15c
> [ 5.587584] acpi_bus_attach+0x123/0x15c
> [ 5.587584] acpi_bus_scan+0x5b/0x6b
> [ 5.587584] acpi_scan_init+0xcd/0x211
> [ 5.587584] acpi_init+0x2e0/0x309
> [ 5.587584] do_one_initcall+0x51/0x1b0
> [ 5.587584] kernel_init_freeable+0x20a/0x2a1
> [ 5.587584] kernel_init+0xe/0x100
> [ 5.587584] ret_from_fork+0x31/0x40
> [ 5.587584] Memory state around the buggy address:
> [ 5.587584] ffff880000141980: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
> [ 5.587584] ffff880000141a00: 00 00 00 00 00 00 00 00 00 03 fc fc fc fc fc fc
> [ 5.587584] >ffff880000141a80: 00 00 00 00 00 00 00 00 05 fc fc fc fc fc fc fc
> [ 5.587584] ^
> [ 5.587584] ffff880000141b00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
> [ 5.587584] ffff880000141b80: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
>
> I'm not sure if this is an ext4 or ACPI problem.

If this is a new bug, you can look for the first bad commit using git-bisect.

I don't recall changing the ACPI code involved in 4.11-rc1, though.

Thanks,
Rafael