<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/uio/uio.c, branch linux-5.9.y</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=linux-5.9.y</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=linux-5.9.y'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2020-11-18T18:22:25+00:00</updated>
<entry>
<title>uio: Fix use-after-free in uio_unregister_device()</title>
<updated>2020-11-18T18:22:25+00:00</updated>
<author>
<name>Shin'ichiro Kawasaki</name>
<email>shinichiro.kawasaki@wdc.com</email>
</author>
<published>2020-11-02T12:28:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=f93a741a19a99d1ea894ddf7d193599f84672ee0'/>
<id>urn:sha1:f93a741a19a99d1ea894ddf7d193599f84672ee0</id>
<content type='text'>
commit 092561f06702dd4fdd7fb74dd3a838f1818529b7 upstream.

Commit 8fd0e2a6df26 ("uio: free uio id after uio file node is freed")
triggered KASAN use-after-free failure at deletion of TCM-user
backstores [1].

In uio_unregister_device(), struct uio_device *idev is passed to
uio_free_minor() to refer idev-&gt;minor. However, before uio_free_minor()
call, idev is already freed by uio_device_release() during call to
device_unregister().

To avoid reference to idev-&gt;minor after idev free, keep idev-&gt;minor
value in a local variable. Also modify uio_free_minor() argument to
receive the value.

[1]
BUG: KASAN: use-after-free in uio_unregister_device+0x166/0x190
Read of size 4 at addr ffff888105196508 by task targetcli/49158

CPU: 3 PID: 49158 Comm: targetcli Not tainted 5.10.0-rc1 #1
Hardware name: Supermicro Super Server/X10SRL-F, BIOS 2.0 12/17/2015
Call Trace:
 dump_stack+0xae/0xe5
 ? uio_unregister_device+0x166/0x190
 print_address_description.constprop.0+0x1c/0x210
 ? uio_unregister_device+0x166/0x190
 ? uio_unregister_device+0x166/0x190
 kasan_report.cold+0x37/0x7c
 ? kobject_put+0x80/0x410
 ? uio_unregister_device+0x166/0x190
 uio_unregister_device+0x166/0x190
 tcmu_destroy_device+0x1c4/0x280 [target_core_user]
 ? tcmu_release+0x90/0x90 [target_core_user]
 ? __mutex_unlock_slowpath+0xd6/0x5d0
 target_free_device+0xf3/0x2e0 [target_core_mod]
 config_item_cleanup+0xea/0x210
 configfs_rmdir+0x651/0x860
 ? detach_groups.isra.0+0x380/0x380
 vfs_rmdir.part.0+0xec/0x3a0
 ? __lookup_hash+0x20/0x150
 do_rmdir+0x252/0x320
 ? do_file_open_root+0x420/0x420
 ? strncpy_from_user+0xbc/0x2f0
 ? getname_flags.part.0+0x8e/0x450
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f9e2bfc91fb
Code: 73 01 c3 48 8b 0d 9d ec 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 54 00 00 00 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 8b 0d 6d ec 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffdd2baafe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007f9e2beb44a0 RCX: 00007f9e2bfc91fb
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f9e1c20be90
RBP: 00007ffdd2bab000 R08: 0000000000000000 R09: 00007f9e2bdf2440
R10: 00007ffdd2baaf37 R11: 0000000000000246 R12: 00000000ffffff9c
R13: 000055f9abb7e390 R14: 000055f9abcf9558 R15: 00007f9e2be7a780

Allocated by task 34735:
 kasan_save_stack+0x1b/0x40
 __kasan_kmalloc.constprop.0+0xc2/0xd0
 __uio_register_device+0xeb/0xd40
 tcmu_configure_device+0x5a0/0xbc0 [target_core_user]
 target_configure_device+0x12f/0x760 [target_core_mod]
 target_dev_enable_store+0x32/0x50 [target_core_mod]
 configfs_write_file+0x2bb/0x450
 vfs_write+0x1ce/0x610
 ksys_write+0xe9/0x1b0
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 49158:
 kasan_save_stack+0x1b/0x40
 kasan_set_track+0x1c/0x30
 kasan_set_free_info+0x1b/0x30
 __kasan_slab_free+0x110/0x150
 slab_free_freelist_hook+0x5a/0x170
 kfree+0xc6/0x560
 device_release+0x9b/0x210
 kobject_put+0x13e/0x410
 uio_unregister_device+0xf9/0x190
 tcmu_destroy_device+0x1c4/0x280 [target_core_user]
 target_free_device+0xf3/0x2e0 [target_core_mod]
 config_item_cleanup+0xea/0x210
 configfs_rmdir+0x651/0x860
 vfs_rmdir.part.0+0xec/0x3a0
 do_rmdir+0x252/0x320
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff888105196000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1288 bytes inside of
 2048-byte region [ffff888105196000, ffff888105196800)
The buggy address belongs to the page:
page:0000000098e6ca81 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x105190
head:0000000098e6ca81 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x17ffffc0010200(slab|head)
raw: 0017ffffc0010200 dead000000000100 dead000000000122 ffff888100043040
raw: 0000000000000000 0000000000080008 00000001ffffffff ffff88810eb55c01
page dumped because: kasan: bad access detected
page-&gt;mem_cgroup:ffff88810eb55c01

Memory state around the buggy address:
 ffff888105196400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888105196480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
&gt;ffff888105196500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888105196580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888105196600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Fixes: 8fd0e2a6df26 ("uio: free uio id after uio file node is freed")
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Shin'ichiro Kawasaki &lt;shinichiro.kawasaki@wdc.com&gt;
Link: https://lore.kernel.org/r/20201102122819.2346270-1-shinichiro.kawasaki@wdc.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>uio: free uio id after uio file node is freed</title>
<updated>2020-11-05T10:51:22+00:00</updated>
<author>
<name>Lang Dai</name>
<email>lang.dai@intel.com</email>
</author>
<published>2020-09-14T03:26:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=1737a0bd8f5ecdd2774f31fe41c7454c355e09c1'/>
<id>urn:sha1:1737a0bd8f5ecdd2774f31fe41c7454c355e09c1</id>
<content type='text'>
[ Upstream commit 8fd0e2a6df262539eaa28b0a2364cca10d1dc662 ]

uio_register_device() do two things.
1) get an uio id from a global pool, e.g. the id is &lt;A&gt;
2) create file nodes like /sys/class/uio/uio&lt;A&gt;

uio_unregister_device() do two things.
1) free the uio id &lt;A&gt; and return it to the global pool
2) free the file node /sys/class/uio/uio&lt;A&gt;

There is a situation is that one worker is calling uio_unregister_device(),
and another worker is calling uio_register_device().
If the two workers are X and Y, they go as below sequence,
1) X free the uio id &lt;AAA&gt;
2) Y get an uio id &lt;AAA&gt;
3) Y create file node /sys/class/uio/uio&lt;AAA&gt;
4) X free the file note /sys/class/uio/uio&lt;AAA&gt;
Then it will failed at the 3rd step and cause the phenomenon we saw as it
is creating a duplicated file node.

Failure reports as follows:
sysfs: cannot create duplicate filename '/class/uio/uio10'
Call Trace:
   sysfs_do_create_link_sd.isra.2+0x9e/0xb0
   sysfs_create_link+0x25/0x40
   device_add+0x2c4/0x640
   __uio_register_device+0x1c5/0x576 [uio]
   adf_uio_init_bundle_dev+0x231/0x280 [intel_qat]
   adf_uio_register+0x1c0/0x340 [intel_qat]
   adf_dev_start+0x202/0x370 [intel_qat]
   adf_dev_start_async+0x40/0xa0 [intel_qat]
   process_one_work+0x14d/0x410
   worker_thread+0x4b/0x460
   kthread+0x105/0x140
 ? process_one_work+0x410/0x410
 ? kthread_bind+0x40/0x40
 ret_from_fork+0x1f/0x40
 Code: 85 c0 48 89 c3 74 12 b9 00 10 00 00 48 89 c2 31 f6 4c 89 ef
 e8 ec c4 ff ff 4c 89 e2 48 89 de 48 c7 c7 e8 b4 ee b4 e8 6a d4 d7
 ff &lt;0f&gt; 0b 48 89 df e8 20 fa f3 ff 5b 41 5c 41 5d 5d c3 66 0f 1f 84
---[ end trace a7531c1ed5269e84 ]---
 c6xxvf b002:00:00.0: Failed to register UIO devices
 c6xxvf b002:00:00.0: Failed to register UIO devices

Signed-off-by: Lang Dai &lt;lang.dai@intel.com&gt;

Link: https://lore.kernel.org/r/1600054002-17722-1-git-send-email-lang.dai@intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>drivers: uio: remove redundant assignment to variable retval</title>
<updated>2020-04-28T13:55:15+00:00</updated>
<author>
<name>Colin Ian King</name>
<email>colin.king@canonical.com</email>
</author>
<published>2020-04-25T12:44:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=56731c68f335ff0ce49e7d8f4fb45eb7805629be'/>
<id>urn:sha1:56731c68f335ff0ce49e7d8f4fb45eb7805629be</id>
<content type='text'>
The variable retval is being initialized with a value that is
never read and it is being updated later with a new value. The
initialization is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King &lt;colin.king@canonical.com&gt;
Link: https://lore.kernel.org/r/20200425124448.139532-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>uio: add resource managed devm_uio_register_device() function</title>
<updated>2020-03-18T11:34:10+00:00</updated>
<author>
<name>Alexandru Ardelean</name>
<email>alexandru.ardelean@analog.com</email>
</author>
<published>2020-03-06T16:18:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=86a78b1cfc78a6378c4ff3b30f822899c066dca5'/>
<id>urn:sha1:86a78b1cfc78a6378c4ff3b30f822899c066dca5</id>
<content type='text'>
This change adds a resource managed equivalent of uio_register_device().
Not adding devm_uio_unregister_device(), since the intent is to discourage
it's usage. Having such a function may allow some bad driver designs. Most
users of devm_*register*() functions rarely use the unregister equivalents.

Signed-off-by: Alexandru Ardelean &lt;alexandru.ardelean@analog.com&gt;
Link: https://lore.kernel.org/r/20200306161853.25368-1-alexandru.ardelean@analog.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>driver: uio: fix possible use-after-free in __uio_register_device</title>
<updated>2019-01-31T15:36:52+00:00</updated>
<author>
<name>Liu Jian</name>
<email>liujian56@huawei.com</email>
</author>
<published>2019-01-22T22:45:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=221a1f4ac12d2ab46246c160b2e00d1b1160d5d9'/>
<id>urn:sha1:221a1f4ac12d2ab46246c160b2e00d1b1160d5d9</id>
<content type='text'>
In uio_dev_add_attributes() error handing case, idev is used after
device_unregister(), in which 'idev' has been released, touch idev cause
use-after-free.

Fixes: a93e7b331568 ("uio: Prevent device destruction while fds are open")
Signed-off-by: Liu Jian &lt;liujian56@huawei.com&gt;
Reviewed-by: Hamish Martin &lt;hamish.martin@alliedtelesis.co.nz&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>driver: uio: fix possible memory leak in __uio_register_device</title>
<updated>2019-01-31T15:36:36+00:00</updated>
<author>
<name>Liu Jian</name>
<email>liujian56@huawei.com</email>
</author>
<published>2019-01-22T22:45:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=1a392b3de7c5747506b38fc14b2e79977d3c7770'/>
<id>urn:sha1:1a392b3de7c5747506b38fc14b2e79977d3c7770</id>
<content type='text'>
'idev' is malloced in __uio_register_device() and leak free it before
leaving from the uio_get_minor() error handing case, it will cause
memory leak.

Fixes: a93e7b331568 ("uio: Prevent device destruction while fds are open")
Signed-off-by: Liu Jian &lt;liujian56@huawei.com&gt;
Reviewed-by: Hamish Martin &lt;hamish.martin@alliedtelesis.co.nz&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>uio: remove redundant check</title>
<updated>2019-01-22T11:03:16+00:00</updated>
<author>
<name>Chengguang Xu</name>
<email>cgxu519@gmx.com</email>
</author>
<published>2019-01-19T13:15:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=54557665a4e776a1affa132faea87bc60c452617'/>
<id>urn:sha1:54557665a4e776a1affa132faea87bc60c452617</id>
<content type='text'>
It is not necessary to check idev-&gt;info several times under
mutex lock, so just remove redundant check.

Signed-off-by: Chengguang Xu &lt;cgxu519@gmx.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>uio: fix potential memory leak in error case</title>
<updated>2019-01-22T11:03:16+00:00</updated>
<author>
<name>Chengguang Xu</name>
<email>cgxu519@gmx.com</email>
</author>
<published>2019-01-17T09:27:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=1e09cdd506c8833a9d52cb61009798660cff4051'/>
<id>urn:sha1:1e09cdd506c8833a9d52cb61009798660cff4051</id>
<content type='text'>
Should jump to lable err_infoopen when idev-&gt;info is NULL
in uio_open().

Signed-off-by: Chengguang Xu &lt;cgxu519@gmx.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>uio: dismiss waiters on device unregistration</title>
<updated>2018-11-27T10:19:10+00:00</updated>
<author>
<name>Zhaolong Zhang</name>
<email>zhangzl2013@126.com</email>
</author>
<published>2018-11-16T10:21:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=b5570ca7c475bffbc5fc2e9af994dc6d249eb13e'/>
<id>urn:sha1:b5570ca7c475bffbc5fc2e9af994dc6d249eb13e</id>
<content type='text'>
When the device is unregistered, it should wake up the blocking waiters.
Otherwise, they will sleep forever.

Signed-off-by: Zhaolong Zhang &lt;zhangzl2013@126.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>uio: Fix an Oops on load</title>
<updated>2018-11-11T17:21:46+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2018-10-26T07:19:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=432798195bbce1f8cd33d1c0284d0538835e25fb'/>
<id>urn:sha1:432798195bbce1f8cd33d1c0284d0538835e25fb</id>
<content type='text'>
I was trying to solve a double free but I introduced a more serious
NULL dereference bug.  The problem is that if there is an IRQ which
triggers immediately, then we need "info-&gt;uio_dev" but it's not set yet.

This patch puts the original initialization back to how it was and just
sets info-&gt;uio_dev to NULL on the error path so it should solve both
the Oops and the double free.

Fixes: f019f07ecf6a ("uio: potential double frees if __uio_register_device() fails")
Reported-by: Mathias Thore &lt;Mathias.Thore@infinera.com&gt;
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Tested-by: Mathias Thore &lt;Mathias.Thore@infinera.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
