linux-stable.git/drivers/mtd/ubi, branch v3.12.45 Linux kernel stable tree UBI: fix soft lockup in ubi_check_volume() 2015-05-15T07:10:44+00:00 hujianyang hujianyang@huawei.com 2014-12-30T03:56:09+00:00 359b12b2647191a879bbc10b3d18a46cb8a604b3 commit 9aa272b492e7551a9ee0e2c83c720ea013698485 upstream. Running mtd-utils/tests/ubi-tests/io_basic.c could cause soft lockup or watchdog reset. It is because *updatevol* will perform ubi_check_volume() after updating finish and this function will full scan the updated lebs if the volume is initialized as STATIC_VOLUME. This patch adds *cond_resched()* in the loop of lebs scan to avoid soft lockup. Helped by Richard Weinberger <richard@nod.at> [ 2158.067096] INFO: rcu_sched self-detected stall on CPU { 1} (t=2101 jiffies g=1606 c=1605 q=56) [ 2158.172867] CPU: 1 PID: 2073 Comm: io_basic Tainted: G O 3.10.53 #21 [ 2158.172898] [<c000f624>] (unwind_backtrace+0x0/0x120) from [<c000c294>] (show_stack+0x10/0x14) [ 2158.172918] [<c000c294>] (show_stack+0x10/0x14) from [<c008ac3c>] (rcu_check_callbacks+0x1c0/0x660) [ 2158.172936] [<c008ac3c>] (rcu_check_callbacks+0x1c0/0x660) from [<c002b480>] (update_process_times+0x38/0x64) [ 2158.172953] [<c002b480>] (update_process_times+0x38/0x64) from [<c005ff38>] (tick_sched_handle+0x54/0x60) [ 2158.172966] [<c005ff38>] (tick_sched_handle+0x54/0x60) from [<c00601ac>] (tick_sched_timer+0x44/0x74) [ 2158.172978] [<c00601ac>] (tick_sched_timer+0x44/0x74) from [<c003f348>] (__run_hrtimer+0xc8/0x1b8) [ 2158.172992] [<c003f348>] (__run_hrtimer+0xc8/0x1b8) from [<c003fd9c>] (hrtimer_interrupt+0x128/0x2a4) [ 2158.173007] [<c003fd9c>] (hrtimer_interrupt+0x128/0x2a4) from [<c0246f1c>] (arch_timer_handler_virt+0x28/0x30) [ 2158.173022] [<c0246f1c>] (arch_timer_handler_virt+0x28/0x30) from [<c0086214>] (handle_percpu_devid_irq+0x9c/0x124) [ 2158.173036] [<c0086214>] (handle_percpu_devid_irq+0x9c/0x124) from [<c0082bd8>] (generic_handle_irq+0x20/0x30) [ 2158.173049] [<c0082bd8>] (generic_handle_irq+0x20/0x30) from [<c000969c>] (handle_IRQ+0x64/0x8c) [ 2158.173060] [<c000969c>] (handle_IRQ+0x64/0x8c) from [<c0008544>] (gic_handle_irq+0x3c/0x60) [ 2158.173074] [<c0008544>] (gic_handle_irq+0x3c/0x60) from [<c02f0f80>] (__irq_svc+0x40/0x50) [ 2158.173083] Exception stack(0xc4043c98 to 0xc4043ce0) [ 2158.173092] 3c80: c4043ce4 00000019 [ 2158.173102] 3ca0: 1f8a865f c050ad10 1f8a864c 00000031 c04b5970 0003ebce 00000000 f3550000 [ 2158.173113] 3cc0: bf00bc68 00000800 0003ebce c4043ce0 c0186d14 c0186cb8 80000013 ffffffff [ 2158.173130] [<c02f0f80>] (__irq_svc+0x40/0x50) from [<c0186cb8>] (read_current_timer+0x4/0x38) [ 2158.173145] [<c0186cb8>] (read_current_timer+0x4/0x38) from [<1f8a865f>] (0x1f8a865f) [ 2183.927097] BUG: soft lockup - CPU#1 stuck for 22s! [io_basic:2073] [ 2184.002229] Modules linked in: nandflash(O) [last unloaded: nandflash] Signed-off-by: Wang Kai <morgan.wang@huawei.com> Signed-off-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit 9aa272b492e7551a9ee0e2c83c720ea013698485 upstream.

Running mtd-utils/tests/ubi-tests/io_basic.c could cause
soft lockup or watchdog reset. It is because *updatevol*
will perform ubi_check_volume() after updating finish
and this function will full scan the updated lebs if the
volume is initialized as STATIC_VOLUME.

This patch adds *cond_resched()* in the loop of lebs scan
to avoid soft lockup.

Helped by Richard Weinberger <richard@nod.at>

[ 2158.067096] INFO: rcu_sched self-detected stall on CPU { 1}  (t=2101 jiffies g=1606 c=1605 q=56)
[ 2158.172867] CPU: 1 PID: 2073 Comm: io_basic Tainted: G           O 3.10.53 #21
[ 2158.172898] [<c000f624>] (unwind_backtrace+0x0/0x120) from [<c000c294>] (show_stack+0x10/0x14)
[ 2158.172918] [<c000c294>] (show_stack+0x10/0x14) from [<c008ac3c>] (rcu_check_callbacks+0x1c0/0x660)
[ 2158.172936] [<c008ac3c>] (rcu_check_callbacks+0x1c0/0x660) from [<c002b480>] (update_process_times+0x38/0x64)
[ 2158.172953] [<c002b480>] (update_process_times+0x38/0x64) from [<c005ff38>] (tick_sched_handle+0x54/0x60)
[ 2158.172966] [<c005ff38>] (tick_sched_handle+0x54/0x60) from [<c00601ac>] (tick_sched_timer+0x44/0x74)
[ 2158.172978] [<c00601ac>] (tick_sched_timer+0x44/0x74) from [<c003f348>] (__run_hrtimer+0xc8/0x1b8)
[ 2158.172992] [<c003f348>] (__run_hrtimer+0xc8/0x1b8) from [<c003fd9c>] (hrtimer_interrupt+0x128/0x2a4)
[ 2158.173007] [<c003fd9c>] (hrtimer_interrupt+0x128/0x2a4) from [<c0246f1c>] (arch_timer_handler_virt+0x28/0x30)
[ 2158.173022] [<c0246f1c>] (arch_timer_handler_virt+0x28/0x30) from [<c0086214>] (handle_percpu_devid_irq+0x9c/0x124)
[ 2158.173036] [<c0086214>] (handle_percpu_devid_irq+0x9c/0x124) from [<c0082bd8>] (generic_handle_irq+0x20/0x30)
[ 2158.173049] [<c0082bd8>] (generic_handle_irq+0x20/0x30) from [<c000969c>] (handle_IRQ+0x64/0x8c)
[ 2158.173060] [<c000969c>] (handle_IRQ+0x64/0x8c) from [<c0008544>] (gic_handle_irq+0x3c/0x60)
[ 2158.173074] [<c0008544>] (gic_handle_irq+0x3c/0x60) from [<c02f0f80>] (__irq_svc+0x40/0x50)
[ 2158.173083] Exception stack(0xc4043c98 to 0xc4043ce0)
[ 2158.173092] 3c80:                                                       c4043ce4 00000019
[ 2158.173102] 3ca0: 1f8a865f c050ad10 1f8a864c 00000031 c04b5970 0003ebce 00000000 f3550000
[ 2158.173113] 3cc0: bf00bc68 00000800 0003ebce c4043ce0 c0186d14 c0186cb8 80000013 ffffffff
[ 2158.173130] [<c02f0f80>] (__irq_svc+0x40/0x50) from [<c0186cb8>] (read_current_timer+0x4/0x38)
[ 2158.173145] [<c0186cb8>] (read_current_timer+0x4/0x38) from [<1f8a865f>] (0x1f8a865f)
[ 2183.927097] BUG: soft lockup - CPU#1 stuck for 22s! [io_basic:2073]
[ 2184.002229] Modules linked in: nandflash(O) [last unloaded: nandflash]

Signed-off-by: Wang Kai <morgan.wang@huawei.com>
Signed-off-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
UBI: fix check for "too many bytes" 2015-05-04T09:50:09+00:00 Brian Norris computersforpeace@gmail.com 2015-02-28T10:23:28+00:00 6e86d18aa0f3615c66d7ae47d78c7717e8ef0234 commit 299d0c5b27346a77a0777c993372bf8777d4f2e5 upstream. The comparison from the previous line seems to have been erroneously (partially) copied-and-pasted onto the next. The second line should be checking req.bytes, not req.lnum. Coverity CID #139400 Signed-off-by: Brian Norris <computersforpeace@gmail.com> [rw: Fixed comparison] Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit 299d0c5b27346a77a0777c993372bf8777d4f2e5 upstream.

The comparison from the previous line seems to have been erroneously
(partially) copied-and-pasted onto the next. The second line should be
checking req.bytes, not req.lnum.

Coverity CID #139400

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
[rw: Fixed comparison]
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
UBI: initialize LEB number variable 2015-05-04T09:50:08+00:00 Brian Norris computersforpeace@gmail.com 2015-02-28T10:23:27+00:00 066f6610ef5196373fd2422e82e6844f38dbb95f commit f16db8071ce18819fbd705ddcc91c6f392fb61f8 upstream. In some of the 'out_not_moved' error paths, lnum may be used uninitialized. Don't ignore the warning; let's fix it. This uninitialized variable doesn't have much visible effect in the end, since we just schedule the PEB for erasure, and its LEB number doesn't really matter (it just gets printed in debug messages). But let's get it straight anyway. Coverity CID #113449 Signed-off-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit f16db8071ce18819fbd705ddcc91c6f392fb61f8 upstream.

In some of the 'out_not_moved' error paths, lnum may be used
uninitialized. Don't ignore the warning; let's fix it.

This uninitialized variable doesn't have much visible effect in the end,
since we just schedule the PEB for erasure, and its LEB number doesn't
really matter (it just gets printed in debug messages). But let's get it
straight anyway.

Coverity CID #113449

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
UBI: fix out of bounds write 2015-05-04T09:50:08+00:00 Brian Norris computersforpeace@gmail.com 2015-02-28T10:23:26+00:00 8926a8a1855b8edc24780c31b6a734901cb42f43 commit d74adbdb9abf0d2506a6c4afa534d894f28b763f upstream. If aeb->len >= vol->reserved_pebs, we should not be writing aeb into the PEB->LEB mapping. Caught by Coverity, CID #711212. Signed-off-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit d74adbdb9abf0d2506a6c4afa534d894f28b763f upstream.

If aeb->len >= vol->reserved_pebs, we should not be writing aeb into the
PEB->LEB mapping.

Caught by Coverity, CID #711212.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
UBI: account for bitflips in both the VID header and data 2015-05-04T09:50:07+00:00 Brian Norris computersforpeace@gmail.com 2015-02-28T10:23:25+00:00 fa4a3fc61b8cfc9c9ee19215906f496804d30751 commit 8eef7d70f7c6772c3490f410ee2bceab3b543fa1 upstream. We are completely discarding the earlier value of 'bitflips', which could reflect a bitflip found in ubi_io_read_vid_hdr(). Let's use the bitwise OR of header and data 'bitflip' statuses instead. Coverity CID #1226856 Signed-off-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit 8eef7d70f7c6772c3490f410ee2bceab3b543fa1 upstream.

We are completely discarding the earlier value of 'bitflips', which
could reflect a bitflip found in ubi_io_read_vid_hdr(). Let's use the
bitwise OR of header and data 'bitflip' statuses instead.

Coverity CID #1226856

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
UBI: Fix double free after do_sync_erase() 2015-01-26T13:38:47+00:00 Richard Weinberger richard@nod.at 2014-11-06T15:47:49+00:00 d97a9dc7ab8bcad943464de5d27e1341bad3ccbb commit aa5ad3b6eb8feb2399a5d26c8fb0060561bb9534 upstream. If the erase worker is unable to erase a PEB it will free the ubi_wl_entry itself. The failing ubi_wl_entry must not free()'d again after do_sync_erase() returns. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit aa5ad3b6eb8feb2399a5d26c8fb0060561bb9534 upstream.

If the erase worker is unable to erase a PEB it will
free the ubi_wl_entry itself.
The failing ubi_wl_entry must not free()'d again after
do_sync_erase() returns.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
UBI: Fix invalid vfree() 2015-01-26T13:38:46+00:00 Richard Weinberger richard@nod.at 2014-10-26T23:46:11+00:00 b4725475530d091cfac701c3d4574b04a6eed21b commit f38aed975c0c3645bbdfc5ebe35726e64caaf588 upstream. The logic of vfree()'ing vol->upd_buf is tied to vol->updating. In ubi_start_update() vol->updating is set long before vmalloc()'ing vol->upd_buf. If we encounter a write failure in ubi_start_update() before vmalloc() the UBI device release function will try to vfree() vol->upd_buf because vol->updating is set. Fix this by allocating vol->upd_buf directly after setting vol->updating. Fixes: [ 31.559338] UBI warning: vol_cdev_release: update of volume 2 not finished, volume is damaged [ 31.559340] ------------[ cut here ]------------ [ 31.559343] WARNING: CPU: 1 PID: 2747 at mm/vmalloc.c:1446 __vunmap+0xe3/0x110() [ 31.559344] Trying to vfree() nonexistent vm area (ffffc90001f2b000) [ 31.559345] Modules linked in: [ 31.565620] 0000000000000bba ffff88002a0cbdb0 ffffffff818f0497 ffff88003b9ba148 [ 31.566347] ffff88002a0cbde0 ffffffff8156f515 ffff88003b9ba148 0000000000000bba [ 31.567073] 0000000000000000 0000000000000000 ffff88002a0cbe88 ffffffff8156c10a [ 31.567793] Call Trace: [ 31.568034] [<ffffffff818f0497>] dump_stack+0x4e/0x7a [ 31.568510] [<ffffffff8156f515>] ubi_io_write_vid_hdr+0x155/0x160 [ 31.569084] [<ffffffff8156c10a>] ubi_eba_write_leb+0x23a/0x870 [ 31.569628] [<ffffffff81569b36>] vol_cdev_write+0x226/0x380 [ 31.570155] [<ffffffff81179265>] vfs_write+0xb5/0x1f0 [ 31.570627] [<ffffffff81179f8a>] SyS_pwrite64+0x6a/0xa0 [ 31.571123] [<ffffffff818fde12>] system_call_fastpath+0x16/0x1b Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit f38aed975c0c3645bbdfc5ebe35726e64caaf588 upstream.

The logic of vfree()'ing vol->upd_buf is tied to vol->updating.
In ubi_start_update() vol->updating is set long before vmalloc()'ing
vol->upd_buf. If we encounter a write failure in ubi_start_update()
before vmalloc() the UBI device release function will try to vfree()
vol->upd_buf because vol->updating is set.
Fix this by allocating vol->upd_buf directly after setting vol->updating.

Fixes:
[   31.559338] UBI warning: vol_cdev_release: update of volume 2 not finished, volume is damaged
[   31.559340] ------------[ cut here ]------------
[   31.559343] WARNING: CPU: 1 PID: 2747 at mm/vmalloc.c:1446 __vunmap+0xe3/0x110()
[   31.559344] Trying to vfree() nonexistent vm area (ffffc90001f2b000)
[   31.559345] Modules linked in:
[   31.565620]  0000000000000bba ffff88002a0cbdb0 ffffffff818f0497 ffff88003b9ba148
[   31.566347]  ffff88002a0cbde0 ffffffff8156f515 ffff88003b9ba148 0000000000000bba
[   31.567073]  0000000000000000 0000000000000000 ffff88002a0cbe88 ffffffff8156c10a
[   31.567793] Call Trace:
[   31.568034]  [<ffffffff818f0497>] dump_stack+0x4e/0x7a
[   31.568510]  [<ffffffff8156f515>] ubi_io_write_vid_hdr+0x155/0x160
[   31.569084]  [<ffffffff8156c10a>] ubi_eba_write_leb+0x23a/0x870
[   31.569628]  [<ffffffff81569b36>] vol_cdev_write+0x226/0x380
[   31.570155]  [<ffffffff81179265>] vfs_write+0xb5/0x1f0
[   31.570627]  [<ffffffff81179f8a>] SyS_pwrite64+0x6a/0xa0
[   31.571123]  [<ffffffff818fde12>] system_call_fastpath+0x16/0x1b

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
UBI: add missing kmem_cache_free() in process_pool_aeb error path 2014-11-13T18:02:17+00:00 Richard Genoud richard.genoud@gmail.com 2014-09-09T12:25:01+00:00 c7077ed405a94651d01822ab8390ab1b84bf341a commit 1bf1890e86869032099b539bc83b098be12fc5a7 upstream. I ran into this error after a ubiupdatevol, because I forgot to backport e9110361a9a4 UBI: fix the volumes tree sorting criteria. UBI error: process_pool_aeb: orphaned volume in fastmap pool UBI error: ubi_scan_fastmap: Attach by fastmap failed, doing a full scan! kmem_cache_destroy ubi_ainf_peb_slab: Slab cache still has objects CPU: 0 PID: 1 Comm: swapper Not tainted 3.14.18-00053-gf05cac8dbf85 #1 [<c000d298>] (unwind_backtrace) from [<c000baa8>] (show_stack+0x10/0x14) [<c000baa8>] (show_stack) from [<c01b7a68>] (destroy_ai+0x230/0x244) [<c01b7a68>] (destroy_ai) from [<c01b8fd4>] (ubi_attach+0x98/0x1ec) [<c01b8fd4>] (ubi_attach) from [<c01ade90>] (ubi_attach_mtd_dev+0x2b8/0x868) [<c01ade90>] (ubi_attach_mtd_dev) from [<c038b510>] (ubi_init+0x1dc/0x2ac) [<c038b510>] (ubi_init) from [<c0008860>] (do_one_initcall+0x94/0x140) [<c0008860>] (do_one_initcall) from [<c037aadc>] (kernel_init_freeable+0xe8/0x1b0) [<c037aadc>] (kernel_init_freeable) from [<c02730ac>] (kernel_init+0x8/0xe4) [<c02730ac>] (kernel_init) from [<c00093f0>] (ret_from_fork+0x14/0x24) UBI: scanning is finished Freeing the cache in the error path fixes the Slab error. Tested on at91sam9g35 (3.14.18+fastmap backports) Signed-off-by: Richard Genoud <richard.genoud@gmail.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit 1bf1890e86869032099b539bc83b098be12fc5a7 upstream.

I ran into this error after a ubiupdatevol, because I forgot to backport
e9110361a9a4 UBI: fix the volumes tree sorting criteria.

UBI error: process_pool_aeb: orphaned volume in fastmap pool
UBI error: ubi_scan_fastmap: Attach by fastmap failed, doing a full scan!
kmem_cache_destroy ubi_ainf_peb_slab: Slab cache still has objects
CPU: 0 PID: 1 Comm: swapper Not tainted 3.14.18-00053-gf05cac8dbf85 #1
[<c000d298>] (unwind_backtrace) from [<c000baa8>] (show_stack+0x10/0x14)
[<c000baa8>] (show_stack) from [<c01b7a68>] (destroy_ai+0x230/0x244)
[<c01b7a68>] (destroy_ai) from [<c01b8fd4>] (ubi_attach+0x98/0x1ec)
[<c01b8fd4>] (ubi_attach) from [<c01ade90>] (ubi_attach_mtd_dev+0x2b8/0x868)
[<c01ade90>] (ubi_attach_mtd_dev) from [<c038b510>] (ubi_init+0x1dc/0x2ac)
[<c038b510>] (ubi_init) from [<c0008860>] (do_one_initcall+0x94/0x140)
[<c0008860>] (do_one_initcall) from [<c037aadc>] (kernel_init_freeable+0xe8/0x1b0)
[<c037aadc>] (kernel_init_freeable) from [<c02730ac>] (kernel_init+0x8/0xe4)
[<c02730ac>] (kernel_init) from [<c00093f0>] (ret_from_fork+0x14/0x24)
UBI: scanning is finished

Freeing the cache in the error path fixes the Slab error.

Tested on at91sam9g35 (3.14.18+fastmap backports)

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
UBI: Fix invalidate_fastmap() 2013-08-20T14:53:25+00:00 Richard Weinberger richard@nod.at 2013-08-19T20:31:49+00:00 8930fa500f55215f0211db9b78255e727ac3f282 Onging tests uncovered that invalidate_fastmap() is broken. It must not call ubi_wl_put_fm_peb() because all PEBs used by the old fastmap have already been put back. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> 
Onging tests uncovered that invalidate_fastmap() is broken.
It must not call ubi_wl_put_fm_peb() because all PEBs used
by the old fastmap have already been put back.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
UBI: Fix PEB leak in wear_leveling_worker() 2013-08-19T15:15:11+00:00 Richard Weinberger richard@nod.at 2013-08-19T06:48:12+00:00 5ef4414f4bc26a19cfd5cd11aee9697a863e4d51 get_peb_for_wl() removes the PEB from the free list. If the WL subsystem detects that no wear leveling is needed it cancels the operation and drops the gained PEB. In this case we have to put the PEB back into the free list. This issue was introduced with commit ed4b7021c (UBI: remove PEB from free tree in get_peb_for_wl()). Cc: <stable@vger.kernel.org> # 3.7.x Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> 
get_peb_for_wl() removes the PEB from the free list.
If the WL subsystem detects that no wear leveling is needed
it cancels the operation and drops the gained PEB.
In this case we have to put the PEB back into the free list.

This issue was introduced with commit ed4b7021c
(UBI: remove PEB from free tree in get_peb_for_wl()).

Cc: <stable@vger.kernel.org> # 3.7.x
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>