Re: [v4] Add security.* XATTR support for the UBIFS

From: Marc Kleine-Budde
Date: Wed Jan 16 2013 - 16:49:05 EST

On 01/15/2013 04:48 PM, Marc Kleine-Budde wrote:
> On 05/13/2012 05:24 AM, Subodh Nijsure wrote:
>> From: Subodh Nijsure <snijsure@xxxxxxxxxxxx>
>>
>> Also fix couple of bugs in UBIFS extended attribute length calculation.
>>
>> Changes in v4:
>> Fix lock issues introduced in v3.
>> Tested with CONFIG_SECURITY enabled & disabled.
>>
>> Changes in v3:
>> Remove #ifdef CONFIG_UBIFS_FS_XATTR
>>
>> Changes in v2:
>> Instead of just handling security.selinux extended attribute handle
>> all security.* attributes.
>>
>> TESTING: Tested on MX28 based platforms using Micron MT29F2G08ABAEAH4 NAND
>> With these change we are able to label UBIFS filesystem with
>> security.selinux and run system with selinux enabled.
>> This change also allows one to set other security.* extended
>> attributes, such as security.smack security.evm, security.ima
>> Ran integck test on UBI filesystem.
>> This patch set has been tested with CONFIG_LOCKDEP=y and other options
>> suggested in Submitchecklist
>>
>> Signed-off-by: Subodh Nijsure <snijsure@xxxxxxxxxxxx>
>
> What's the status of this patch? Was there a v5?

I've ported v4 to v3.7.2 and get this deadlock:

> [ 18.870000] UBIFS: background thread "ubifs_bgt0_0" started, PID 101
> [ 20.650000]
> [ 20.650000] ======================================================
> [ 20.650000] [ INFO: possible circular locking dependency detected ]
> [ 20.650000] 3.7.2-00001-g8cdd29c #2 Not tainted
> [ 20.650000] -------------------------------------------------------
> [ 20.650000] systemd-rc-once/79 is trying to acquire lock:
> [ 20.650000] (&sb->s_type->i_mutex_key#9){+.+.+.}, at: [<c01afe64>] ubifs_init_security+0x28/0x74
> [ 20.650000]
> [ 20.650000] but task is already holding lock:
> [ 20.650000] (&ui->ui_mutex){+.+...}, at: [<c018a404>] ubifs_create+0x9c/0x1f8
> [ 20.650000]
> [ 20.650000] which lock already depends on the new lock.
> [ 20.650000]
> [ 20.650000]
> [ 20.650000] the existing dependency chain (in reverse order) is:
> [ 20.650000]
> -> #1 (&ui->ui_mutex){+.+...}:
> [ 20.650000] [<c0054c3c>] lock_acquire+0x64/0x78
> [ 20.650000] [<c0391b80>] mutex_lock_nested+0x68/0x2f8
> [ 20.650000] [<c01876fc>] ubifs_setattr+0xe4/0x3ec
> [ 20.650000] [<c00c8f48>] notify_change+0x1dc/0x324
> [ 20.650000] [<c00af3c8>] do_truncate+0x78/0x94
> [ 20.650000] [<c00bd738>] do_last.isra.24+0x530/0xc30
> [ 20.650000] [<c00bdee0>] path_openat+0xa8/0x4b8
> [ 20.650000] [<c00be5ec>] do_filp_open+0x2c/0x80
> [ 20.650000] [<c00b0128>] do_sys_open+0xe4/0x170
> [ 20.650000] [<c000e260>] ret_fast_syscall+0x0/0x38
> [ 20.650000]
> -> #0 (&sb->s_type->i_mutex_key#9){+.+.+.}:
> [ 20.650000] [<c0054138>] __lock_acquire+0x1354/0x19b0
> [ 20.650000] [<c0054c3c>] lock_acquire+0x64/0x78
> [ 20.650000] [<c0391b80>] mutex_lock_nested+0x68/0x2f8
> [ 20.650000] [<c01afe64>] ubifs_init_security+0x28/0x74
> [ 20.650000] [<c018a488>] ubifs_create+0x120/0x1f8
> [ 20.650000] [<c00bb7d4>] vfs_create+0xac/0xd8
> [ 20.650000] [<c00bdcb8>] do_last.isra.24+0xab0/0xc30
> [ 20.650000] [<c00bdee0>] path_openat+0xa8/0x4b8
> [ 20.650000] [<c00be5ec>] do_filp_open+0x2c/0x80
> [ 20.650000] [<c00b0128>] do_sys_open+0xe4/0x170
> [ 20.650000] [<c000e260>] ret_fast_syscall+0x0/0x38
> [ 20.650000]
> [ 20.650000] other info that might help us debug this:
> [ 20.650000]
> [ 20.650000] Possible unsafe locking scenario:
> [ 20.650000]
> [ 20.650000] CPU0 CPU1
> [ 20.650000] ---- ----
> [ 20.650000] lock(&ui->ui_mutex);
> [ 20.650000] lock(&sb->s_type->i_mutex_key#9);
> [ 20.650000] lock(&ui->ui_mutex);
> [ 20.650000] lock(&sb->s_type->i_mutex_key#9);
> [ 20.650000]
> [ 20.650000] *** DEADLOCK ***
> [ 20.650000]
> [ 20.650000] 3 locks held by systemd-rc-once/79:
> [ 20.650000] #0: (sb_writers#3){.+.+.+}, at: [<c00cc300>] mnt_want_write+0x18/0x3c
> [ 20.650000] #1: (&type->i_mutex_dir_key){+.+.+.}, at: [<c00bd4ac>] do_last.isra.24+0x2a4/0xc30
> [ 20.650000] #2: (&ui->ui_mutex){+.+...}, at: [<c018a404>] ubifs_create+0x9c/0x1f8
> [ 20.650000]
> [ 20.650000] stack backtrace:
> [ 20.650000] [<c00123e8>] (unwind_backtrace+0x0/0xf0) from [<c038c874>] (print_circular_bug+0x254/0x2a0)
> [ 20.650000] [<c038c874>] (print_circular_bug+0x254/0x2a0) from [<c0054138>] (__lock_acquire+0x1354/0x19b0)
> [ 20.650000] [<c0054138>] (__lock_acquire+0x1354/0x19b0) from [<c0054c3c>] (lock_acquire+0x64/0x78)
> [ 20.650000] [<c0054c3c>] (lock_acquire+0x64/0x78) from [<c0391b80>] (mutex_lock_nested+0x68/0x2f8)
> [ 20.650000] [<c0391b80>] (mutex_lock_nested+0x68/0x2f8) from [<c01afe64>] (ubifs_init_security+0x28/0x74)
> [ 20.650000] [<c01afe64>] (ubifs_init_security+0x28/0x74) from [<c018a488>] (ubifs_create+0x120/0x1f8)
> [ 20.650000] [<c018a488>] (ubifs_create+0x120/0x1f8) from [<c00bb7d4>] (vfs_create+0xac/0xd8)
> [ 20.650000] [<c00bb7d4>] (vfs_create+0xac/0xd8) from [<c00bdcb8>] (do_last.isra.24+0xab0/0xc30)
> [ 20.650000] [<c00bdcb8>] (do_last.isra.24+0xab0/0xc30) from [<c00bdee0>] (path_openat+0xa8/0x4b8)
> [ 20.650000] [<c00bdee0>] (path_openat+0xa8/0x4b8) from [<c00be5ec>] (do_filp_open+0x2c/0x80)
> [ 20.650000] [<c00be5ec>] (do_filp_open+0x2c/0x80) from [<c00b0128>] (do_sys_open+0xe4/0x170)
> [ 20.650000] [<c00b0128>] (do_sys_open+0xe4/0x170) from [<c000e260>] (ret_fast_syscall+0x0/0x38)
> [ 49.430000] UBIFS: background thread "ubifs_bgt0_0" stops

Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
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