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Rabin Vincent 8a1435880f ubi: fastmap: Fix slab corruption
Booting with UBI fastmap and SLUB debugging enabled results in the
following splats.  The problem is that ubi_scan_fastmap() moves the
fastmap blocks from the scan_ai (allocated in scan_fast()) to the ai
allocated in ubi_attach().  This results in two problems:

 - When the scan_ai is freed, aebs which were allocated from its slab
   cache are still in use.

 - When the other ai is being destroyed in destroy_ai(), the
   arguments to kmem_cache_free() call are incorrect since aebs on its
   ->fastmap list were allocated with a slab cache from a differnt ai.

Fix this by making a copy of the aebs in ubi_scan_fastmap() instead of
moving them.

 =============================================================================
 BUG ubi_aeb_slab_cache (Not tainted): Objects remaining in ubi_aeb_slab_cache on __kmem_cache_shutdown()
 -----------------------------------------------------------------------------

 INFO: Slab 0xbfd2da3c objects=17 used=1 fp=0xb33d7748 flags=0x40000080
 CPU: 1 PID: 118 Comm: ubiattach Tainted: G    B           4.9.15 #3
 [<80111910>] (unwind_backtrace) from [<8010d498>] (show_stack+0x18/0x1c)
 [<8010d498>] (show_stack) from [<804a3274>] (dump_stack+0xb4/0xe0)
 [<804a3274>] (dump_stack) from [<8026c47c>] (slab_err+0x78/0x88)
 [<8026c47c>] (slab_err) from [<802735bc>] (__kmem_cache_shutdown+0x180/0x3e0)
 [<802735bc>] (__kmem_cache_shutdown) from [<8024e13c>] (shutdown_cache+0x1c/0x60)
 [<8024e13c>] (shutdown_cache) from [<8024ed64>] (kmem_cache_destroy+0x19c/0x20c)
 [<8024ed64>] (kmem_cache_destroy) from [<8057cc14>] (destroy_ai+0x1dc/0x1e8)
 [<8057cc14>] (destroy_ai) from [<8057f04c>] (ubi_attach+0x3f4/0x450)
 [<8057f04c>] (ubi_attach) from [<8056fe70>] (ubi_attach_mtd_dev+0x60c/0xff8)
 [<8056fe70>] (ubi_attach_mtd_dev) from [<80571d78>] (ctrl_cdev_ioctl+0x110/0x2b8)
 [<80571d78>] (ctrl_cdev_ioctl) from [<8029c77c>] (do_vfs_ioctl+0xac/0xa00)
 [<8029c77c>] (do_vfs_ioctl) from [<8029d10c>] (SyS_ioctl+0x3c/0x64)
 [<8029d10c>] (SyS_ioctl) from [<80108860>] (ret_fast_syscall+0x0/0x1c)
 INFO: Object 0xb33d7e88 @offset=3720
 INFO: Allocated in scan_peb+0x608/0x81c age=72 cpu=1 pid=118
 	kmem_cache_alloc+0x3b0/0x43c
 	scan_peb+0x608/0x81c
 	ubi_attach+0x124/0x450
 	ubi_attach_mtd_dev+0x60c/0xff8
 	ctrl_cdev_ioctl+0x110/0x2b8
 	do_vfs_ioctl+0xac/0xa00
 	SyS_ioctl+0x3c/0x64
 	ret_fast_syscall+0x0/0x1c
 kmem_cache_destroy ubi_aeb_slab_cache: Slab cache still has objects
 CPU: 1 PID: 118 Comm: ubiattach Tainted: G    B           4.9.15 #3
 [<80111910>] (unwind_backtrace) from [<8010d498>] (show_stack+0x18/0x1c)
 [<8010d498>] (show_stack) from [<804a3274>] (dump_stack+0xb4/0xe0)
 [<804a3274>] (dump_stack) from [<8024ed80>] (kmem_cache_destroy+0x1b8/0x20c)
 [<8024ed80>] (kmem_cache_destroy) from [<8057cc14>] (destroy_ai+0x1dc/0x1e8)
 [<8057cc14>] (destroy_ai) from [<8057f04c>] (ubi_attach+0x3f4/0x450)
 [<8057f04c>] (ubi_attach) from [<8056fe70>] (ubi_attach_mtd_dev+0x60c/0xff8)
 [<8056fe70>] (ubi_attach_mtd_dev) from [<80571d78>] (ctrl_cdev_ioctl+0x110/0x2b8)
 [<80571d78>] (ctrl_cdev_ioctl) from [<8029c77c>] (do_vfs_ioctl+0xac/0xa00)
 [<8029c77c>] (do_vfs_ioctl) from [<8029d10c>] (SyS_ioctl+0x3c/0x64)
 [<8029d10c>] (SyS_ioctl) from [<80108860>] (ret_fast_syscall+0x0/0x1c)
 cache_from_obj: Wrong slab cache. ubi_aeb_slab_cache but object is from ubi_aeb_slab_cache
 ------------[ cut here ]------------
 WARNING: CPU: 1 PID: 118 at mm/slab.h:354 kmem_cache_free+0x39c/0x450
 Modules linked in:
 CPU: 1 PID: 118 Comm: ubiattach Tainted: G    B           4.9.15 #3
 [<80111910>] (unwind_backtrace) from [<8010d498>] (show_stack+0x18/0x1c)
 [<8010d498>] (show_stack) from [<804a3274>] (dump_stack+0xb4/0xe0)
 [<804a3274>] (dump_stack) from [<80120e40>] (__warn+0xf4/0x10c)
 [<80120e40>] (__warn) from [<80120f20>] (warn_slowpath_null+0x28/0x30)
 [<80120f20>] (warn_slowpath_null) from [<80271fe0>] (kmem_cache_free+0x39c/0x450)
 [<80271fe0>] (kmem_cache_free) from [<8057cb88>] (destroy_ai+0x150/0x1e8)
 [<8057cb88>] (destroy_ai) from [<8057ef1c>] (ubi_attach+0x2c4/0x450)
 [<8057ef1c>] (ubi_attach) from [<8056fe70>] (ubi_attach_mtd_dev+0x60c/0xff8)
 [<8056fe70>] (ubi_attach_mtd_dev) from [<80571d78>] (ctrl_cdev_ioctl+0x110/0x2b8)
 [<80571d78>] (ctrl_cdev_ioctl) from [<8029c77c>] (do_vfs_ioctl+0xac/0xa00)
 [<8029c77c>] (do_vfs_ioctl) from [<8029d10c>] (SyS_ioctl+0x3c/0x64)
 [<8029d10c>] (SyS_ioctl) from [<80108860>] (ret_fast_syscall+0x0/0x1c)
 ---[ end trace 2bd8396277fd0a0b ]---
 =============================================================================
 BUG ubi_aeb_slab_cache (Tainted: G    B   W      ): page slab pointer corrupt.
 -----------------------------------------------------------------------------

 INFO: Allocated in scan_peb+0x608/0x81c age=104 cpu=1 pid=118
 	kmem_cache_alloc+0x3b0/0x43c
 	scan_peb+0x608/0x81c
 	ubi_attach+0x124/0x450
 	ubi_attach_mtd_dev+0x60c/0xff8
 	ctrl_cdev_ioctl+0x110/0x2b8
 	do_vfs_ioctl+0xac/0xa00
 	SyS_ioctl+0x3c/0x64
 	ret_fast_syscall+0x0/0x1c
 INFO: Slab 0xbfd2da3c objects=17 used=1 fp=0xb33d7748 flags=0x40000081
 INFO: Object 0xb33d7e88 @offset=3720 fp=0xb33d7da0

 Redzone b33d7e80: cc cc cc cc cc cc cc cc                          ........
 Object b33d7e88: 02 00 00 00 01 00 00 00 00 f0 ff 7f ff ff ff ff  ................
 Object b33d7e98: 00 00 00 00 00 00 00 00 bd 16 00 00 00 00 00 00  ................
 Object b33d7ea8: 00 01 00 00 00 02 00 00 00 00 00 00 00 00 00 00  ................
 Redzone b33d7eb8: cc cc cc cc                                      ....
 Padding b33d7f60: 5a 5a 5a 5a 5a 5a 5a 5a                          ZZZZZZZZ
 CPU: 1 PID: 118 Comm: ubiattach Tainted: G    B   W       4.9.15 #3
 [<80111910>] (unwind_backtrace) from [<8010d498>] (show_stack+0x18/0x1c)
 [<8010d498>] (show_stack) from [<804a3274>] (dump_stack+0xb4/0xe0)
 [<804a3274>] (dump_stack) from [<80271770>] (free_debug_processing+0x320/0x3c4)
 [<80271770>] (free_debug_processing) from [<80271ad0>] (__slab_free+0x2bc/0x430)
 [<80271ad0>] (__slab_free) from [<80272024>] (kmem_cache_free+0x3e0/0x450)
 [<80272024>] (kmem_cache_free) from [<8057cb88>] (destroy_ai+0x150/0x1e8)
 [<8057cb88>] (destroy_ai) from [<8057ef1c>] (ubi_attach+0x2c4/0x450)
 [<8057ef1c>] (ubi_attach) from [<8056fe70>] (ubi_attach_mtd_dev+0x60c/0xff8)
 [<8056fe70>] (ubi_attach_mtd_dev) from [<80571d78>] (ctrl_cdev_ioctl+0x110/0x2b8)
 [<80571d78>] (ctrl_cdev_ioctl) from [<8029c77c>] (do_vfs_ioctl+0xac/0xa00)
 [<8029c77c>] (do_vfs_ioctl) from [<8029d10c>] (SyS_ioctl+0x3c/0x64)
 [<8029d10c>] (SyS_ioctl) from [<80108860>] (ret_fast_syscall+0x0/0x1c)
 FIX ubi_aeb_slab_cache: Object at 0xb33d7e88 not freed

Signed-off-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-05-08 20:48:33 +02:00
arch Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-04-30 11:44:18 -07:00
block blk-mq: fix potential oops with polling and blk-mq scheduler 2017-04-20 14:53:28 -06:00
certs certs: Add a secondary system keyring that can be added to dynamically 2016-04-11 22:48:09 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-04-18 09:03:50 -07:00
Documentation pci-v4.11-fixes-5 2017-04-21 09:26:34 -07:00
drivers ubi: fastmap: Fix slab corruption 2017-05-08 20:48:33 +02:00
firmware WHENCE: use https://linuxtv.org for LinuxTV URLs 2015-12-04 10:35:11 -02:00
fs ubifs: Add CONFIG_UBIFS_FS_SECURITY to disable/enable security labels 2017-05-08 20:48:23 +02:00
include Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-04-27 11:09:37 -07:00
init mm: move mm_percpu_wq initialization earlier 2017-03-31 17:13:30 -07:00
ipc Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
kernel sched/cputime: Fix ksoftirqd cputime accounting regression 2017-04-27 09:08:26 +02:00
lib Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-04-29 14:00:42 -07:00
mm mm: prevent NR_ISOLATE_* stats from going negative 2017-04-20 15:30:18 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-28 14:13:16 -07:00
samples statx: Include a mask for stx_attributes in struct statx 2017-04-03 01:06:00 -04:00
scripts Kbuild fixes for v4.11 2017-04-05 08:37:28 -07:00
security KEYS: fix keyctl_set_reqkey_keyring() to not leak thread keyrings 2017-04-18 15:31:49 +01:00
sound ASoC: Fixes for v4.11 2017-04-25 17:43:56 +02:00
tools bpf: Fix values type used in test_maps 2017-04-21 15:16:46 -04:00
usr kbuild: initramfs cleanup, set target from Kconfig 2017-01-05 09:40:16 -08:00
virt KVM/ARM Fixes for v4.11-rc6 2017-04-05 16:27:47 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:48:52 -04:00
.mailmap mailmap: add Martin Kepplinger's email 2017-04-13 18:24:21 -07:00
COPYING
CREDITS MAINTAINERS: Remove old e-mail address 2017-02-13 12:24:56 -05:00
Kbuild scripts/gdb: provide linux constants 2016-05-23 17:04:14 -07:00
Kconfig
MAINTAINERS bpf, doc: update bpf maintainers entry 2017-04-21 15:25:10 -04:00
Makefile Linux 4.11 2017-04-30 19:47:48 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
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Please read the Documentation/process/changes.rst file, as it contains the
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