* SELinux + ubifs: possible circular locking dependency [not found] <51123C80.2050400@pengutronix.de> @ 2013-02-08 14:10 ` Marc Kleine-Budde 2013-02-13 12:47 ` Artem Bityutskiy 0 siblings, 1 reply; 6+ messages in thread From: Marc Kleine-Budde @ 2013-02-08 14:10 UTC (permalink / raw) To: linux-mtd; +Cc: linux-security-module, LKML, kernel@pengutronix.de [-- Attachment #1: Type: text/plain, Size: 10547 bytes --] Hello, I'm on a arm imx28 v3.8-rc6 (+ a handfull of patches to support the custom board) but no modifications on ubifs, selinux or the vfs layer. And not including the xattr patches by Subodh Nijsure. When booting with SELinux and lockdep enabled I see this _possible_ circular locking dependency: This warning shows up every boot, but not again later. Is lockep automatically disabled after the first circular lockdep warning? This particular situation, where the dependency chain is occurs as far as I understand only at boot. Three functions in this chain are only called once: - pinctrl_init() - clk_debug_init() - mount_block_root() Another critical ingredient is security_load_policy(). Is this really an uncritical catch of the lock validator? If so, is it possible to annotate this, so that the system boot up quietly? > [ 5.390312] ====================================================== > [ 5.396500] [ INFO: possible circular locking dependency detected ] > [ 5.402781] 3.8.0-rc6-00005-g4f7e39d #49 Not tainted > [ 5.407750] ------------------------------------------------------- > [ 5.414031] systemd/1 is trying to acquire lock: > [ 5.418656] (&c->tnc_mutex){+.+...}, at: [<c01552d0>] ubifs_tnc_locate+0x30/0x198 > [ 5.426343] > [ 5.426343] but task is already holding lock: > [ 5.432218] (&isec->lock){+.+.+.}, at: [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c > [ 5.440375] > [ 5.440375] which lock already depends on the new lock. > [ 5.440375] > [ 5.448593] > [ 5.448593] the existing dependency chain (in reverse order) is: > [ 5.456093] > -> #4 (&isec->lock){+.+.+.}: > [ 5.460250] [<c004e8e8>] lock_acquire+0x64/0x78 > [ 5.465437] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec > [ 5.471125] [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c > [ 5.477437] [<c0189bd8>] security_d_instantiate+0x1c/0x34 > [ 5.483500] [<c017a614>] debugfs_mknod.part.15.constprop.18+0x94/0x128 > [ 5.490656] [<c017a858>] __create_file+0x1b0/0x25c > [ 5.496093] [<c017a98c>] debugfs_create_dir+0x1c/0x28 > [ 5.501781] [<c0491ce8>] pinctrl_init+0x1c/0xd0 > [ 5.506968] [<c0008900>] do_one_initcall+0x108/0x17c > [ 5.512593] [<c0483858>] kernel_init_freeable+0xec/0x1b4 > [ 5.518562] [<c034f398>] kernel_init+0x8/0xe4 > [ 5.523562] [<c0009448>] ret_from_fork+0x14/0x2c > [ 5.528812] > -> #3 (&sb->s_type->i_mutex_key#2){+.+.+.}: > [ 5.534312] [<c004e8e8>] lock_acquire+0x64/0x78 > [ 5.539468] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec > [ 5.545187] [<c017a6f8>] __create_file+0x50/0x25c > [ 5.550531] [<c017a98c>] debugfs_create_dir+0x1c/0x28 > [ 5.556218] [<c026cfc4>] clk_debug_create_subtree+0x1c/0x108 > [ 5.562500] [<c0495bfc>] clk_debug_init+0x68/0xc0 > [ 5.567875] [<c0008900>] do_one_initcall+0x108/0x17c > [ 5.573468] [<c0483858>] kernel_init_freeable+0xec/0x1b4 > [ 5.579437] [<c034f398>] kernel_init+0x8/0xe4 > [ 5.584437] [<c0009448>] ret_from_fork+0x14/0x2c > [ 5.589687] > -> #2 (prepare_lock){+.+.+.}: > [ 5.593937] [<c004e8e8>] lock_acquire+0x64/0x78 > [ 5.599125] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec > [ 5.604812] [<c026d400>] clk_prepare+0x18/0x38 > [ 5.609906] [<c023a2f8>] __gpmi_enable_clk+0x30/0xb0 > [ 5.615531] [<c023a7bc>] gpmi_begin+0x18/0x530 > [ 5.620625] [<c0239244>] gpmi_select_chip+0x3c/0x54 > [ 5.626156] [<c02341ac>] nand_do_read_ops+0x7c/0x3e4 > [ 5.631750] [<c023483c>] nand_read+0x50/0x74 > [ 5.636656] [<c02198e4>] part_read+0x5c/0xa4 > [ 5.641593] [<c0217404>] mtd_read+0x84/0xb8 > [ 5.646406] [<c02450cc>] ubi_io_read+0xa0/0x2c0 > [ 5.651593] [<c0242640>] ubi_eba_read_leb+0x190/0x424 > [ 5.657281] [<c0241b18>] ubi_leb_read+0xac/0x120 > [ 5.662562] [<c01503e4>] ubifs_leb_read+0x28/0x8c > [ 5.667906] [<c0151f74>] ubifs_read_node+0x98/0x2a0 > [ 5.673437] [<c014e780>] ubifs_read_sb_node+0x54/0x78 > [ 5.679125] [<c014f444>] ubifs_read_superblock+0xc60/0x163c > [ 5.685343] [<c014d64c>] ubifs_mount+0x800/0x171c > [ 5.690687] [<c00b5740>] mount_fs+0x44/0x184 > [ 5.695593] [<c00cd7ec>] vfs_kern_mount+0x4c/0xc0 > [ 5.700968] [<c00cf394>] do_mount+0x18c/0x8d0 > [ 5.705968] [<c00cfb5c>] sys_mount+0x84/0xb8 > [ 5.710875] [<c0483bc8>] mount_block_root+0x118/0x258 > [ 5.716562] [<c0483eac>] prepare_namespace+0x8c/0x17c > [ 5.722281] [<c034f398>] kernel_init+0x8/0xe4 > [ 5.727281] [<c0009448>] ret_from_fork+0x14/0x2c > [ 5.732531] > -> #1 (&le->mutex){++++..}: > [ 5.736625] [<c004e8e8>] lock_acquire+0x64/0x78 > [ 5.741812] [<c0356468>] down_read+0x40/0x54 > [ 5.746718] [<c02424e4>] ubi_eba_read_leb+0x34/0x424 > [ 5.752312] [<c0241b18>] ubi_leb_read+0xac/0x120 > [ 5.757562] [<c01503e4>] ubifs_leb_read+0x28/0x8c > [ 5.762937] [<c0151f74>] ubifs_read_node+0x98/0x2a0 > [ 5.768437] [<c016edc0>] ubifs_load_znode+0x88/0x560 > [ 5.774062] [<c0155254>] ubifs_lookup_level0+0x190/0x1dc > [ 5.780031] [<c01552e4>] ubifs_tnc_locate+0x44/0x198 > [ 5.785656] [<c014c614>] ubifs_iget+0x6c/0x8a4 > [ 5.790718] [<c014da64>] ubifs_mount+0xc18/0x171c > [ 5.796093] [<c00b5740>] mount_fs+0x44/0x184 > [ 5.801000] [<c00cd7ec>] vfs_kern_mount+0x4c/0xc0 > [ 5.806343] [<c00cf394>] do_mount+0x18c/0x8d0 > [ 5.811343] [<c00cfb5c>] sys_mount+0x84/0xb8 > [ 5.816250] [<c0483bc8>] mount_block_root+0x118/0x258 > [ 5.821968] [<c0483eac>] prepare_namespace+0x8c/0x17c > [ 5.827656] [<c034f398>] kernel_init+0x8/0xe4 > [ 5.832656] [<c0009448>] ret_from_fork+0x14/0x2c > [ 5.837906] > -> #0 (&c->tnc_mutex){+.+...}: > [ 5.842250] [<c004de48>] __lock_acquire+0x14ec/0x1b08 > [ 5.847968] [<c004e8e8>] lock_acquire+0x64/0x78 > [ 5.853125] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec > [ 5.858812] [<c01552d0>] ubifs_tnc_locate+0x30/0x198 > [ 5.864437] [<c0155a48>] ubifs_tnc_lookup_nm+0x28/0x150 > [ 5.870312] [<c016fc18>] ubifs_getxattr+0xc0/0x254 > [ 5.875750] [<c018e468>] inode_doinit_with_dentry+0x25c/0x55c > [ 5.882125] [<c018f1a8>] sb_finish_set_opts+0xa4/0x21c > [ 5.887906] [<c019055c>] selinux_set_mnt_opts+0x2ec/0x4b8 > [ 5.893968] [<c01907dc>] superblock_doinit+0xb4/0xc0 > [ 5.899562] [<c00b51f4>] iterate_supers+0xb4/0xdc > [ 5.904906] [<c01a02e8>] security_load_policy+0x248/0x3c4 > [ 5.910968] [<c0194994>] sel_write_load+0x9c/0x6a0 > [ 5.916406] [<c00b2148>] vfs_write+0xa0/0x17c > [ 5.921406] [<c00b2450>] sys_write+0x3c/0x70 > [ 5.926343] [<c00093a0>] ret_fast_syscall+0x0/0x38 > [ 5.931781] > [ 5.931781] other info that might help us debug this: > [ 5.931781] > [ 5.939781] Chain exists of: > &c->tnc_mutex --> &sb->s_type->i_mutex_key#2 --> &isec->lock > [ 5.948500] Possible unsafe locking scenario: > [ 5.948500] > [ 5.954437] CPU0 CPU1 > [ 5.958968] ---- ---- > [ 5.963500] lock(&isec->lock); > [ 5.966781] lock(&sb->s_type->i_mutex_key#2); > [ 5.973843] lock(&isec->lock); > [ 5.979625] lock(&c->tnc_mutex); > [ 5.983062] > [ 5.983062] *** DEADLOCK *** > [ 5.983062] > [ 5.989000] 4 locks held by systemd/1: > [ 5.992781] #0: (sel_mutex){+.+.+.}, at: [<c0194918>] sel_write_load+0x20/0x6a0 > [ 6.000343] #1: (&type->s_umount_key#26){.+.+..}, at: [<c00b51d0>] iterate_supers+0x90/0xdc > [ 6.008968] #2: (&sbsec->lock){+.+.+.}, at: [<c01902d4>] selinux_set_mnt_opts+0x64/0x4b8 > [ 6.017343] #3: (&isec->lock){+.+.+.}, at: [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c > [ 6.025937] > [ 6.025937] stack backtrace: > [ 6.030375] [<c000d0f0>] (unwind_backtrace+0x0/0xf0) from [<c0351a2c>] (print_circular_bug+0x25c/0x2a8) > [ 6.039843] [<c0351a2c>] (print_circular_bug+0x25c/0x2a8) from [<c004de48>] (__lock_acquire+0x14ec/0x1b08) > [ 6.049531] [<c004de48>] (__lock_acquire+0x14ec/0x1b08) from [<c004e8e8>] (lock_acquire+0x64/0x78) > [ 6.058531] [<c004e8e8>] (lock_acquire+0x64/0x78) from [<c0355d5c>] (mutex_lock_nested+0x5c/0x2ec) > [ 6.067531] [<c0355d5c>] (mutex_lock_nested+0x5c/0x2ec) from [<c01552d0>] (ubifs_tnc_locate+0x30/0x198) > [ 6.076968] [<c01552d0>] (ubifs_tnc_locate+0x30/0x198) from [<c0155a48>] (ubifs_tnc_lookup_nm+0x28/0x150) > [ 6.086593] [<c0155a48>] (ubifs_tnc_lookup_nm+0x28/0x150) from [<c016fc18>] (ubifs_getxattr+0xc0/0x254) > [ 6.096031] [<c016fc18>] (ubifs_getxattr+0xc0/0x254) from [<c018e468>] (inode_doinit_with_dentry+0x25c/0x55c) > [ 6.105968] [<c018e468>] (inode_doinit_with_dentry+0x25c/0x55c) from [<c018f1a8>] (sb_finish_set_opts+0xa4/0x21c) > [ 6.116281] [<c018f1a8>] (sb_finish_set_opts+0xa4/0x21c) from [<c019055c>] (selinux_set_mnt_opts+0x2ec/0x4b8) > [ 6.126218] [<c019055c>] (selinux_set_mnt_opts+0x2ec/0x4b8) from [<c01907dc>] (superblock_doinit+0xb4/0xc0) > [ 6.136000] [<c01907dc>] (superblock_doinit+0xb4/0xc0) from [<c00b51f4>] (iterate_supers+0xb4/0xdc) > [ 6.145093] [<c00b51f4>] (iterate_supers+0xb4/0xdc) from [<c01a02e8>] (security_load_policy+0x248/0x3c4) > [ 6.154625] [<c01a02e8>] (security_load_policy+0x248/0x3c4) from [<c0194994>] (sel_write_load+0x9c/0x6a0) > [ 6.164218] [<c0194994>] (sel_write_load+0x9c/0x6a0) from [<c00b2148>] (vfs_write+0xa0/0x17c) > [ 6.172781] [<c00b2148>] (vfs_write+0xa0/0x17c) from [<c00b2450>] (sys_write+0x3c/0x70) > [ 6.180843] [<c00b2450>] (sys_write+0x3c/0x70) from [<c00093a0>] (ret_fast_syscall+0x0/0x38) regards, Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 263 bytes --] ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: SELinux + ubifs: possible circular locking dependency 2013-02-08 14:10 ` SELinux + ubifs: possible circular locking dependency Marc Kleine-Budde @ 2013-02-13 12:47 ` Artem Bityutskiy 2013-02-13 14:37 ` Marc Kleine-Budde 0 siblings, 1 reply; 6+ messages in thread From: Artem Bityutskiy @ 2013-02-13 12:47 UTC (permalink / raw) To: Marc Kleine-Budde Cc: linux-mtd, linux-security-module, LKML, kernel@pengutronix.de [-- Attachment #1: Type: text/plain, Size: 11283 bytes --] On Fri, 2013-02-08 at 15:10 +0100, Marc Kleine-Budde wrote: > Hello, > > I'm on a arm imx28 v3.8-rc6 (+ a handfull of patches to support the > custom board) but no modifications on ubifs, selinux or the vfs layer. > And not including the xattr patches by Subodh Nijsure. > > When booting with SELinux and lockdep enabled I see this _possible_ > circular locking dependency: I guess one needs to really understand how lockdep works, because it seems there is no direct 'tnc_mutex -> isec->lock', and lockdep somehow deducts this connection inderectly. However, it seems I see what _may_ be the reason, and here is a patch which I think may fix the issue. Would you please test/review it? It is inlined and also attached. >From a2b29a190227959bdeadf8d412745003c86857ef Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Date: Wed, 13 Feb 2013 13:49:14 +0200 Subject: [PATCH] selinux: do not confuse lockdep Selinux initializes all per-inode 'isec->lock' mutexes in one single place, which makes lockdep believe they all belong to the same class, which will make lockdep treat all 'isec->lock' mutexes equivalent. This leads to a lockdep false-positive reported by Marc Kleine-Budde <mkl@pengutronix.de> (see at the end). Frankly, I failed to understand the warning and this fix is more of a guess of what would be the root-cause. I would appreciate if someone could explain me what this warning actually tells, because I cannot see any 'c->tnc_mutex -> isec->lock' chain in the code! Where this chain comes from: "&c->tnc_mutex --> &sb->s_type->i_mutex_key#2 --> &isec->lock" The lockdep complaint: Look at the stacktrace #4: here we have 'debugfs_create_dir()' [ 5.390312] ====================================================== [ 5.396500] [ INFO: possible circular locking dependency detected ] [ 5.402781] 3.8.0-rc6-00005-g4f7e39d #49 Not tainted [ 5.407750] ------------------------------------------------------- [ 5.414031] systemd/1 is trying to acquire lock: [ 5.418656] (&c->tnc_mutex){+.+...}, at: [<c01552d0>] ubifs_tnc_locate+0x30/0x198 [ 5.426343] [ 5.426343] but task is already holding lock: [ 5.432218] (&isec->lock){+.+.+.}, at: [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 5.440375] [ 5.440375] which lock already depends on the new lock. [ 5.440375] [ 5.448593] [ 5.448593] the existing dependency chain (in reverse order) is: [ 5.456093] -> #4 (&isec->lock){+.+.+.}: [ 5.460250] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.465437] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.471125] [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 5.477437] [<c0189bd8>] security_d_instantiate+0x1c/0x34 [ 5.483500] [<c017a614>] debugfs_mknod.part.15.constprop.18+0x94/0x128 [ 5.490656] [<c017a858>] __create_file+0x1b0/0x25c [ 5.496093] [<c017a98c>] debugfs_create_dir+0x1c/0x28 [ 5.501781] [<c0491ce8>] pinctrl_init+0x1c/0xd0 [ 5.506968] [<c0008900>] do_one_initcall+0x108/0x17c [ 5.512593] [<c0483858>] kernel_init_freeable+0xec/0x1b4 [ 5.518562] [<c034f398>] kernel_init+0x8/0xe4 [ 5.523562] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.528812] -> #3 (&sb->s_type->i_mutex_key#2){+.+.+.}: [ 5.534312] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.539468] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.545187] [<c017a6f8>] __create_file+0x50/0x25c [ 5.550531] [<c017a98c>] debugfs_create_dir+0x1c/0x28 [ 5.556218] [<c026cfc4>] clk_debug_create_subtree+0x1c/0x108 [ 5.562500] [<c0495bfc>] clk_debug_init+0x68/0xc0 [ 5.567875] [<c0008900>] do_one_initcall+0x108/0x17c [ 5.573468] [<c0483858>] kernel_init_freeable+0xec/0x1b4 [ 5.579437] [<c034f398>] kernel_init+0x8/0xe4 [ 5.584437] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.589687] -> #2 (prepare_lock){+.+.+.}: [ 5.593937] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.599125] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.604812] [<c026d400>] clk_prepare+0x18/0x38 [ 5.609906] [<c023a2f8>] __gpmi_enable_clk+0x30/0xb0 [ 5.615531] [<c023a7bc>] gpmi_begin+0x18/0x530 [ 5.620625] [<c0239244>] gpmi_select_chip+0x3c/0x54 [ 5.626156] [<c02341ac>] nand_do_read_ops+0x7c/0x3e4 [ 5.631750] [<c023483c>] nand_read+0x50/0x74 [ 5.636656] [<c02198e4>] part_read+0x5c/0xa4 [ 5.641593] [<c0217404>] mtd_read+0x84/0xb8 [ 5.646406] [<c02450cc>] ubi_io_read+0xa0/0x2c0 [ 5.651593] [<c0242640>] ubi_eba_read_leb+0x190/0x424 [ 5.657281] [<c0241b18>] ubi_leb_read+0xac/0x120 [ 5.662562] [<c01503e4>] ubifs_leb_read+0x28/0x8c [ 5.667906] [<c0151f74>] ubifs_read_node+0x98/0x2a0 [ 5.673437] [<c014e780>] ubifs_read_sb_node+0x54/0x78 [ 5.679125] [<c014f444>] ubifs_read_superblock+0xc60/0x163c [ 5.685343] [<c014d64c>] ubifs_mount+0x800/0x171c [ 5.690687] [<c00b5740>] mount_fs+0x44/0x184 [ 5.695593] [<c00cd7ec>] vfs_kern_mount+0x4c/0xc0 [ 5.700968] [<c00cf394>] do_mount+0x18c/0x8d0 [ 5.705968] [<c00cfb5c>] sys_mount+0x84/0xb8 [ 5.710875] [<c0483bc8>] mount_block_root+0x118/0x258 [ 5.716562] [<c0483eac>] prepare_namespace+0x8c/0x17c [ 5.722281] [<c034f398>] kernel_init+0x8/0xe4 [ 5.727281] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.732531] -> #1 (&le->mutex){++++..}: [ 5.736625] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.741812] [<c0356468>] down_read+0x40/0x54 [ 5.746718] [<c02424e4>] ubi_eba_read_leb+0x34/0x424 [ 5.752312] [<c0241b18>] ubi_leb_read+0xac/0x120 [ 5.757562] [<c01503e4>] ubifs_leb_read+0x28/0x8c [ 5.762937] [<c0151f74>] ubifs_read_node+0x98/0x2a0 [ 5.768437] [<c016edc0>] ubifs_load_znode+0x88/0x560 [ 5.774062] [<c0155254>] ubifs_lookup_level0+0x190/0x1dc [ 5.780031] [<c01552e4>] ubifs_tnc_locate+0x44/0x198 [ 5.785656] [<c014c614>] ubifs_iget+0x6c/0x8a4 [ 5.790718] [<c014da64>] ubifs_mount+0xc18/0x171c [ 5.796093] [<c00b5740>] mount_fs+0x44/0x184 [ 5.801000] [<c00cd7ec>] vfs_kern_mount+0x4c/0xc0 [ 5.806343] [<c00cf394>] do_mount+0x18c/0x8d0 [ 5.811343] [<c00cfb5c>] sys_mount+0x84/0xb8 [ 5.816250] [<c0483bc8>] mount_block_root+0x118/0x258 [ 5.821968] [<c0483eac>] prepare_namespace+0x8c/0x17c [ 5.827656] [<c034f398>] kernel_init+0x8/0xe4 [ 5.832656] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.837906] -> #0 (&c->tnc_mutex){+.+...}: [ 5.842250] [<c004de48>] __lock_acquire+0x14ec/0x1b08 [ 5.847968] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.853125] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.858812] [<c01552d0>] ubifs_tnc_locate+0x30/0x198 [ 5.864437] [<c0155a48>] ubifs_tnc_lookup_nm+0x28/0x150 [ 5.870312] [<c016fc18>] ubifs_getxattr+0xc0/0x254 [ 5.875750] [<c018e468>] inode_doinit_with_dentry+0x25c/0x55c [ 5.882125] [<c018f1a8>] sb_finish_set_opts+0xa4/0x21c [ 5.887906] [<c019055c>] selinux_set_mnt_opts+0x2ec/0x4b8 [ 5.893968] [<c01907dc>] superblock_doinit+0xb4/0xc0 [ 5.899562] [<c00b51f4>] iterate_supers+0xb4/0xdc [ 5.904906] [<c01a02e8>] security_load_policy+0x248/0x3c4 [ 5.910968] [<c0194994>] sel_write_load+0x9c/0x6a0 [ 5.916406] [<c00b2148>] vfs_write+0xa0/0x17c [ 5.921406] [<c00b2450>] sys_write+0x3c/0x70 [ 5.926343] [<c00093a0>] ret_fast_syscall+0x0/0x38 [ 5.931781] [ 5.931781] other info that might help us debug this: [ 5.931781] [ 5.939781] Chain exists of: &c->tnc_mutex --> &sb->s_type->i_mutex_key#2 --> &isec->lock [ 5.948500] Possible unsafe locking scenario: [ 5.948500] [ 5.954437] CPU0 CPU1 [ 5.958968] ---- ---- [ 5.963500] lock(&isec->lock); [ 5.966781] lock(&sb->s_type->i_mutex_key#2); [ 5.973843] lock(&isec->lock); [ 5.979625] lock(&c->tnc_mutex); [ 5.983062] [ 5.983062] *** DEADLOCK *** [ 5.983062] [ 5.989000] 4 locks held by systemd/1: [ 5.992781] #0: (sel_mutex){+.+.+.}, at: [<c0194918>] sel_write_load+0x20/0x6a0 [ 6.000343] #1: (&type->s_umount_key#26){.+.+..}, at: [<c00b51d0>] iterate_supers+0x90/0xdc [ 6.008968] #2: (&sbsec->lock){+.+.+.}, at: [<c01902d4>] selinux_set_mnt_opts+0x64/0x4b8 [ 6.017343] #3: (&isec->lock){+.+.+.}, at: [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 6.025937] [ 6.025937] stack backtrace: [ 6.030375] [<c000d0f0>] (unwind_backtrace+0x0/0xf0) from [<c0351a2c>] (print_circular_bug+0x25c/0x2a8) [ 6.039843] [<c0351a2c>] (print_circular_bug+0x25c/0x2a8) from [<c004de48>] (__lock_acquire+0x14ec/0x1b08) [ 6.049531] [<c004de48>] (__lock_acquire+0x14ec/0x1b08) from [<c004e8e8>] (lock_acquire+0x64/0x78) [ 6.058531] [<c004e8e8>] (lock_acquire+0x64/0x78) from [<c0355d5c>] (mutex_lock_nested+0x5c/0x2ec) [ 6.067531] [<c0355d5c>] (mutex_lock_nested+0x5c/0x2ec) from [<c01552d0>] (ubifs_tnc_locate+0x30/0x198) [ 6.076968] [<c01552d0>] (ubifs_tnc_locate+0x30/0x198) from [<c0155a48>] (ubifs_tnc_lookup_nm+0x28/0x150) [ 6.086593] [<c0155a48>] (ubifs_tnc_lookup_nm+0x28/0x150) from [<c016fc18>] (ubifs_getxattr+0xc0/0x254) [ 6.096031] [<c016fc18>] (ubifs_getxattr+0xc0/0x254) from [<c018e468>] (inode_doinit_with_dentry+0x25c/0x55c) [ 6.105968] [<c018e468>] (inode_doinit_with_dentry+0x25c/0x55c) from [<c018f1a8>] (sb_finish_set_opts+0xa4/0x21c) [ 6.116281] [<c018f1a8>] (sb_finish_set_opts+0xa4/0x21c) from [<c019055c>] (selinux_set_mnt_opts+0x2ec/0x4b8) [ 6.126218] [<c019055c>] (selinux_set_mnt_opts+0x2ec/0x4b8) from [<c01907dc>] (superblock_doinit+0xb4/0xc0) [ 6.136000] [<c01907dc>] (superblock_doinit+0xb4/0xc0) from [<c00b51f4>] (iterate_supers+0xb4/0xdc) [ 6.145093] [<c00b51f4>] (iterate_supers+0xb4/0xdc) from [<c01a02e8>] (security_load_policy+0x248/0x3c4) [ 6.154625] [<c01a02e8>] (security_load_policy+0x248/0x3c4) from [<c0194994>] (sel_write_load+0x9c/0x6a0) [ 6.164218] [<c0194994>] (sel_write_load+0x9c/0x6a0) from [<c00b2148>] (vfs_write+0xa0/0x17c) [ 6.172781] [<c00b2148>] (vfs_write+0xa0/0x17c) from [<c00b2450>] (sys_write+0x3c/0x70) [ 6.180843] [<c00b2450>] (sys_write+0x3c/0x70) from [<c00093a0>] (ret_fast_syscall+0x0/0x38) Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> --- security/selinux/hooks.c | 1 + 1 file changed, 1 insertion(+) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ef26e96..328180e 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -207,6 +207,7 @@ static int inode_alloc_security(struct inode *inode) return -ENOMEM; mutex_init(&isec->lock); + lockdep_set_class(&isec->lock, inode->i_sb->s_type->i_mutex_key); INIT_LIST_HEAD(&isec->list); isec->inode = inode; isec->sid = SECINITSID_UNLABELED; -- 1.7.10.4 -- Best Regards, Artem Bityutskiy [-- Attachment #2: 0001-selinux-do-not-confuse-lockdep.patch --] [-- Type: text/x-patch, Size: 10521 bytes --] >From a2b29a190227959bdeadf8d412745003c86857ef Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Date: Wed, 13 Feb 2013 13:49:14 +0200 Subject: [PATCH] selinux: do not confuse lockdep Selinux initializes all per-inode 'isec->lock' mutexes in one single place, which makes lockdep believe they all belong to the same class, which will make lockdep treat all 'isec->lock' mutexes equivalent. This leads to a lockdep false-positive reported by Marc Kleine-Budde <mkl@pengutronix.de> (see at the end). Frankly, I failed to understand the warning and this fix is more of a guess of what would be the root-cause. I would appreciate if someone could explain me what this warning actually tells, because I cannot see any 'c->tnc_mutex -> isec->lock' chain in the code! Where this chain comes from: "&c->tnc_mutex --> &sb->s_type->i_mutex_key#2 --> &isec->lock" The lockdep complaint: Look at the stacktrace #4: here we have 'debugfs_create_dir()' [ 5.390312] ====================================================== [ 5.396500] [ INFO: possible circular locking dependency detected ] [ 5.402781] 3.8.0-rc6-00005-g4f7e39d #49 Not tainted [ 5.407750] ------------------------------------------------------- [ 5.414031] systemd/1 is trying to acquire lock: [ 5.418656] (&c->tnc_mutex){+.+...}, at: [<c01552d0>] ubifs_tnc_locate+0x30/0x198 [ 5.426343] [ 5.426343] but task is already holding lock: [ 5.432218] (&isec->lock){+.+.+.}, at: [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 5.440375] [ 5.440375] which lock already depends on the new lock. [ 5.440375] [ 5.448593] [ 5.448593] the existing dependency chain (in reverse order) is: [ 5.456093] -> #4 (&isec->lock){+.+.+.}: [ 5.460250] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.465437] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.471125] [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 5.477437] [<c0189bd8>] security_d_instantiate+0x1c/0x34 [ 5.483500] [<c017a614>] debugfs_mknod.part.15.constprop.18+0x94/0x128 [ 5.490656] [<c017a858>] __create_file+0x1b0/0x25c [ 5.496093] [<c017a98c>] debugfs_create_dir+0x1c/0x28 [ 5.501781] [<c0491ce8>] pinctrl_init+0x1c/0xd0 [ 5.506968] [<c0008900>] do_one_initcall+0x108/0x17c [ 5.512593] [<c0483858>] kernel_init_freeable+0xec/0x1b4 [ 5.518562] [<c034f398>] kernel_init+0x8/0xe4 [ 5.523562] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.528812] -> #3 (&sb->s_type->i_mutex_key#2){+.+.+.}: [ 5.534312] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.539468] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.545187] [<c017a6f8>] __create_file+0x50/0x25c [ 5.550531] [<c017a98c>] debugfs_create_dir+0x1c/0x28 [ 5.556218] [<c026cfc4>] clk_debug_create_subtree+0x1c/0x108 [ 5.562500] [<c0495bfc>] clk_debug_init+0x68/0xc0 [ 5.567875] [<c0008900>] do_one_initcall+0x108/0x17c [ 5.573468] [<c0483858>] kernel_init_freeable+0xec/0x1b4 [ 5.579437] [<c034f398>] kernel_init+0x8/0xe4 [ 5.584437] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.589687] -> #2 (prepare_lock){+.+.+.}: [ 5.593937] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.599125] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.604812] [<c026d400>] clk_prepare+0x18/0x38 [ 5.609906] [<c023a2f8>] __gpmi_enable_clk+0x30/0xb0 [ 5.615531] [<c023a7bc>] gpmi_begin+0x18/0x530 [ 5.620625] [<c0239244>] gpmi_select_chip+0x3c/0x54 [ 5.626156] [<c02341ac>] nand_do_read_ops+0x7c/0x3e4 [ 5.631750] [<c023483c>] nand_read+0x50/0x74 [ 5.636656] [<c02198e4>] part_read+0x5c/0xa4 [ 5.641593] [<c0217404>] mtd_read+0x84/0xb8 [ 5.646406] [<c02450cc>] ubi_io_read+0xa0/0x2c0 [ 5.651593] [<c0242640>] ubi_eba_read_leb+0x190/0x424 [ 5.657281] [<c0241b18>] ubi_leb_read+0xac/0x120 [ 5.662562] [<c01503e4>] ubifs_leb_read+0x28/0x8c [ 5.667906] [<c0151f74>] ubifs_read_node+0x98/0x2a0 [ 5.673437] [<c014e780>] ubifs_read_sb_node+0x54/0x78 [ 5.679125] [<c014f444>] ubifs_read_superblock+0xc60/0x163c [ 5.685343] [<c014d64c>] ubifs_mount+0x800/0x171c [ 5.690687] [<c00b5740>] mount_fs+0x44/0x184 [ 5.695593] [<c00cd7ec>] vfs_kern_mount+0x4c/0xc0 [ 5.700968] [<c00cf394>] do_mount+0x18c/0x8d0 [ 5.705968] [<c00cfb5c>] sys_mount+0x84/0xb8 [ 5.710875] [<c0483bc8>] mount_block_root+0x118/0x258 [ 5.716562] [<c0483eac>] prepare_namespace+0x8c/0x17c [ 5.722281] [<c034f398>] kernel_init+0x8/0xe4 [ 5.727281] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.732531] -> #1 (&le->mutex){++++..}: [ 5.736625] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.741812] [<c0356468>] down_read+0x40/0x54 [ 5.746718] [<c02424e4>] ubi_eba_read_leb+0x34/0x424 [ 5.752312] [<c0241b18>] ubi_leb_read+0xac/0x120 [ 5.757562] [<c01503e4>] ubifs_leb_read+0x28/0x8c [ 5.762937] [<c0151f74>] ubifs_read_node+0x98/0x2a0 [ 5.768437] [<c016edc0>] ubifs_load_znode+0x88/0x560 [ 5.774062] [<c0155254>] ubifs_lookup_level0+0x190/0x1dc [ 5.780031] [<c01552e4>] ubifs_tnc_locate+0x44/0x198 [ 5.785656] [<c014c614>] ubifs_iget+0x6c/0x8a4 [ 5.790718] [<c014da64>] ubifs_mount+0xc18/0x171c [ 5.796093] [<c00b5740>] mount_fs+0x44/0x184 [ 5.801000] [<c00cd7ec>] vfs_kern_mount+0x4c/0xc0 [ 5.806343] [<c00cf394>] do_mount+0x18c/0x8d0 [ 5.811343] [<c00cfb5c>] sys_mount+0x84/0xb8 [ 5.816250] [<c0483bc8>] mount_block_root+0x118/0x258 [ 5.821968] [<c0483eac>] prepare_namespace+0x8c/0x17c [ 5.827656] [<c034f398>] kernel_init+0x8/0xe4 [ 5.832656] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.837906] -> #0 (&c->tnc_mutex){+.+...}: [ 5.842250] [<c004de48>] __lock_acquire+0x14ec/0x1b08 [ 5.847968] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.853125] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.858812] [<c01552d0>] ubifs_tnc_locate+0x30/0x198 [ 5.864437] [<c0155a48>] ubifs_tnc_lookup_nm+0x28/0x150 [ 5.870312] [<c016fc18>] ubifs_getxattr+0xc0/0x254 [ 5.875750] [<c018e468>] inode_doinit_with_dentry+0x25c/0x55c [ 5.882125] [<c018f1a8>] sb_finish_set_opts+0xa4/0x21c [ 5.887906] [<c019055c>] selinux_set_mnt_opts+0x2ec/0x4b8 [ 5.893968] [<c01907dc>] superblock_doinit+0xb4/0xc0 [ 5.899562] [<c00b51f4>] iterate_supers+0xb4/0xdc [ 5.904906] [<c01a02e8>] security_load_policy+0x248/0x3c4 [ 5.910968] [<c0194994>] sel_write_load+0x9c/0x6a0 [ 5.916406] [<c00b2148>] vfs_write+0xa0/0x17c [ 5.921406] [<c00b2450>] sys_write+0x3c/0x70 [ 5.926343] [<c00093a0>] ret_fast_syscall+0x0/0x38 [ 5.931781] [ 5.931781] other info that might help us debug this: [ 5.931781] [ 5.939781] Chain exists of: &c->tnc_mutex --> &sb->s_type->i_mutex_key#2 --> &isec->lock [ 5.948500] Possible unsafe locking scenario: [ 5.948500] [ 5.954437] CPU0 CPU1 [ 5.958968] ---- ---- [ 5.963500] lock(&isec->lock); [ 5.966781] lock(&sb->s_type->i_mutex_key#2); [ 5.973843] lock(&isec->lock); [ 5.979625] lock(&c->tnc_mutex); [ 5.983062] [ 5.983062] *** DEADLOCK *** [ 5.983062] [ 5.989000] 4 locks held by systemd/1: [ 5.992781] #0: (sel_mutex){+.+.+.}, at: [<c0194918>] sel_write_load+0x20/0x6a0 [ 6.000343] #1: (&type->s_umount_key#26){.+.+..}, at: [<c00b51d0>] iterate_supers+0x90/0xdc [ 6.008968] #2: (&sbsec->lock){+.+.+.}, at: [<c01902d4>] selinux_set_mnt_opts+0x64/0x4b8 [ 6.017343] #3: (&isec->lock){+.+.+.}, at: [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 6.025937] [ 6.025937] stack backtrace: [ 6.030375] [<c000d0f0>] (unwind_backtrace+0x0/0xf0) from [<c0351a2c>] (print_circular_bug+0x25c/0x2a8) [ 6.039843] [<c0351a2c>] (print_circular_bug+0x25c/0x2a8) from [<c004de48>] (__lock_acquire+0x14ec/0x1b08) [ 6.049531] [<c004de48>] (__lock_acquire+0x14ec/0x1b08) from [<c004e8e8>] (lock_acquire+0x64/0x78) [ 6.058531] [<c004e8e8>] (lock_acquire+0x64/0x78) from [<c0355d5c>] (mutex_lock_nested+0x5c/0x2ec) [ 6.067531] [<c0355d5c>] (mutex_lock_nested+0x5c/0x2ec) from [<c01552d0>] (ubifs_tnc_locate+0x30/0x198) [ 6.076968] [<c01552d0>] (ubifs_tnc_locate+0x30/0x198) from [<c0155a48>] (ubifs_tnc_lookup_nm+0x28/0x150) [ 6.086593] [<c0155a48>] (ubifs_tnc_lookup_nm+0x28/0x150) from [<c016fc18>] (ubifs_getxattr+0xc0/0x254) [ 6.096031] [<c016fc18>] (ubifs_getxattr+0xc0/0x254) from [<c018e468>] (inode_doinit_with_dentry+0x25c/0x55c) [ 6.105968] [<c018e468>] (inode_doinit_with_dentry+0x25c/0x55c) from [<c018f1a8>] (sb_finish_set_opts+0xa4/0x21c) [ 6.116281] [<c018f1a8>] (sb_finish_set_opts+0xa4/0x21c) from [<c019055c>] (selinux_set_mnt_opts+0x2ec/0x4b8) [ 6.126218] [<c019055c>] (selinux_set_mnt_opts+0x2ec/0x4b8) from [<c01907dc>] (superblock_doinit+0xb4/0xc0) [ 6.136000] [<c01907dc>] (superblock_doinit+0xb4/0xc0) from [<c00b51f4>] (iterate_supers+0xb4/0xdc) [ 6.145093] [<c00b51f4>] (iterate_supers+0xb4/0xdc) from [<c01a02e8>] (security_load_policy+0x248/0x3c4) [ 6.154625] [<c01a02e8>] (security_load_policy+0x248/0x3c4) from [<c0194994>] (sel_write_load+0x9c/0x6a0) [ 6.164218] [<c0194994>] (sel_write_load+0x9c/0x6a0) from [<c00b2148>] (vfs_write+0xa0/0x17c) [ 6.172781] [<c00b2148>] (vfs_write+0xa0/0x17c) from [<c00b2450>] (sys_write+0x3c/0x70) [ 6.180843] [<c00b2450>] (sys_write+0x3c/0x70) from [<c00093a0>] (ret_fast_syscall+0x0/0x38) Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> --- security/selinux/hooks.c | 1 + 1 file changed, 1 insertion(+) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ef26e96..328180e 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -207,6 +207,7 @@ static int inode_alloc_security(struct inode *inode) return -ENOMEM; mutex_init(&isec->lock); + lockdep_set_class(&isec->lock, inode->i_sb->s_type->i_mutex_key); INIT_LIST_HEAD(&isec->list); isec->inode = inode; isec->sid = SECINITSID_UNLABELED; -- 1.7.10.4 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: SELinux + ubifs: possible circular locking dependency 2013-02-13 12:47 ` Artem Bityutskiy @ 2013-02-13 14:37 ` Marc Kleine-Budde 2013-02-14 6:36 ` Artem Bityutskiy 2013-02-14 7:15 ` Artem Bityutskiy 0 siblings, 2 replies; 6+ messages in thread From: Marc Kleine-Budde @ 2013-02-13 14:37 UTC (permalink / raw) To: dedekind1; +Cc: linux-mtd, linux-security-module, LKML, kernel@pengutronix.de [-- Attachment #1: Type: text/plain, Size: 7083 bytes --] On 02/13/2013 01:47 PM, Artem Bityutskiy wrote: >> I'm on a arm imx28 v3.8-rc6 (+ a handfull of patches to support the >> custom board) but no modifications on ubifs, selinux or the vfs layer. >> And not including the xattr patches by Subodh Nijsure. >> >> When booting with SELinux and lockdep enabled I see this _possible_ >> circular locking dependency: > > I guess one needs to really understand how lockdep works, because it > seems there is no direct 'tnc_mutex -> isec->lock', and lockdep somehow > deducts this connection inderectly. > > However, it seems I see what _may_ be the reason, and here is a patch > which I think may fix the issue. Would you please test/review it? It is > inlined and also attached. Thanks, [...] The compiler complains security/selinux/hooks.c:210:2: error: incompatible type for argument 3 of 'lockdep_init_map' In file included from include/linux/spinlock_types.h:18:0, from include/linux/spinlock.h:81, from include/linux/seqlock.h:29, from include/linux/time.h:5, from include/uapi/linux/timex.h:56, from include/linux/timex.h:56, from include/linux/sched.h:17, from include/linux/tracehook.h:49, from security/selinux/hooks.c:29: include/linux/lockdep.h:279:13: note: expected 'struct lock_class_key *' but argument is of type 'struct lock_class_key' > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index ef26e96..328180e 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -207,6 +207,7 @@ static int inode_alloc_security(struct inode *inode) > return -ENOMEM; > > mutex_init(&isec->lock); > + lockdep_set_class(&isec->lock, inode->i_sb->s_type->i_mutex_key); So I added an "&", so that the line looks like that: + lockdep_set_class(&isec->lock, &inode->i_sb->s_type->i_mutex_key); > INIT_LIST_HEAD(&isec->list); > isec->inode = inode; > isec->sid = SECINITSID_UNLABELED; > That solves original circular lock warning, but brings these two: > [ 0.213843] ------------[ cut here ]------------ > [ 0.218687] WARNING: at kernel/lockdep.c:702 __lock_acquire+0x1824/0x1c58() > [ 0.225875] Modules linked in: > [ 0.229156] [<c000d0f0>] (unwind_backtrace+0x0/0xf0) from [<c001575c>] (warn_slowpath_common+0x4c/0x64) > [ 0.238812] [<c001575c>] (warn_slowpath_common+0x4c/0x64) from [<c0015790>] (warn_slowpath_null+0x1c/0x24) > [ 0.248750] [<c0015790>] (warn_slowpath_null+0x1c/0x24) from [<c00548f0>] (__lock_acquire+0x1824/0x1c58) > [ 0.258500] [<c00548f0>] (__lock_acquire+0x1824/0x1c58) from [<c0055210>] (lock_acquire+0x88/0x9c) > [ 0.267750] [<c0055210>] (lock_acquire+0x88/0x9c) from [<c0390aa4>] (mutex_lock_nested+0x5c/0x2ec) > [ 0.276968] [<c0390aa4>] (mutex_lock_nested+0x5c/0x2ec) from [<c00dcf04>] (lock_mount+0x1c/0xbc) > [ 0.286031] [<c00dcf04>] (lock_mount+0x1c/0xbc) from [<c00dd310>] (do_add_mount+0x18/0xc8) > [ 0.294531] [<c00dd310>] (do_add_mount+0x18/0xc8) from [<c00de17c>] (do_mount+0x1cc/0x8d0) > [ 0.303062] [<c00de17c>] (do_mount+0x1cc/0x8d0) from [<c00de904>] (sys_mount+0x84/0xb8) > [ 0.311343] [<c00de904>] (sys_mount+0x84/0xb8) from [<c022cf58>] (devtmpfsd+0x4c/0x2b8) > [ 0.319593] [<c022cf58>] (devtmpfsd+0x4c/0x2b8) from [<c0034a58>] (kthread+0xa4/0xb0) > [ 0.327656] [<c0034a58>] (kthread+0xa4/0xb0) from [<c0009448>] (ret_from_fork+0x14/0x2c) > [ 0.336062] ---[ end trace 1b75b31a2719ed1c ]--- The warning comes from: list_for_each_entry(class, hash_head, hash_entry) { if (class->key == key) { /* * Huh! same key, different name? Did someone trample * on some memory? We're most confused. */ WARN_ON_ONCE(class->name != lock->name); return class; } } [...] > [ 0.342000] devtmpfs: initialized > [ 0.350187] pinctrl core: initialized pinctrl subsystem > [ 0.358000] > [ 0.359656] ============================================= > [ 0.365218] [ INFO: possible recursive locking detected ] > [ 0.370812] 3.8.0-rc7-00011-g7a589e1-dirty #108 Tainted: G W > [ 0.377562] --------------------------------------------- > [ 0.383125] swapper/1 is trying to acquire lock: > [ 0.387906] (&inode->i_sb->s_type->i_mutex_key#7){+.+.+.}, at: [<c01a988c>] inode_doinit_with_dentry+0x8c/0x55c > [ 0.398437] > [ 0.398437] but task is already holding lock: > [ 0.404562] (&inode->i_sb->s_type->i_mutex_key#7){+.+.+.}, at: [<c0191bd4>] __create_file+0x50/0x25c > [ 0.414093] > [ 0.414093] other info that might help us debug this: > [ 0.420906] Possible unsafe locking scenario: > [ 0.420906] > [ 0.427125] CPU0 > [ 0.429687] ---- > [ 0.432250] lock(&inode->i_sb->s_type->i_mutex_key#7); > [ 0.437781] lock(&inode->i_sb->s_type->i_mutex_key#7); > [ 0.443312] > [ 0.443312] *** DEADLOCK *** > [ 0.443312] > [ 0.449593] May be due to missing lock nesting notation > [ 0.449593] > [ 0.456687] 1 lock held by swapper/1: > [ 0.460500] #0: (&inode->i_sb->s_type->i_mutex_key#7){+.+.+.}, at: [<c0191bd4>] __create_file+0x50/0x25c > [ 0.470468] > [ 0.470468] stack backtrace: > [ 0.475125] [<c000d0f0>] (unwind_backtrace+0x0/0xf0) from [<c0054578>] (__lock_acquire+0x14ac/0x1c58) > [ 0.484625] [<c0054578>] (__lock_acquire+0x14ac/0x1c58) from [<c0055210>] (lock_acquire+0x88/0x9c) > [ 0.493843] [<c0055210>] (lock_acquire+0x88/0x9c) from [<c0390aa4>] (mutex_lock_nested+0x5c/0x2ec) > [ 0.503093] [<c0390aa4>] (mutex_lock_nested+0x5c/0x2ec) from [<c01a988c>] (inode_doinit_with_dentry+0x8c/0x55c) > [ 0.513468] [<c01a988c>] (inode_doinit_with_dentry+0x8c/0x55c) from [<c01a3f9c>] (security_d_instantiate+0x1c/0x34) > [ 0.524187] [<c01a3f9c>] (security_d_instantiate+0x1c/0x34) from [<c0191af0>] (debugfs_mknod.part.15.constprop.18+0x94/0x128) > [ 0.535812] [<c0191af0>] (debugfs_mknod.part.15.constprop.18+0x94/0x128) from [<c0191d34>] (__create_file+0x1b0/0x25c) > [ 0.546781] [<c0191d34>] (__create_file+0x1b0/0x25c) from [<c0191e68>] (debugfs_create_dir+0x1c/0x28) > [ 0.556312] [<c0191e68>] (debugfs_create_dir+0x1c/0x28) from [<c04d1f58>] (pinctrl_init+0x1c/0xd0) > [ 0.565531] [<c04d1f58>] (pinctrl_init+0x1c/0xd0) from [<c0008900>] (do_one_initcall+0x108/0x17c) > [ 0.574656] [<c0008900>] (do_one_initcall+0x108/0x17c) from [<c04c3858>] (kernel_init_freeable+0xec/0x1b4) > [ 0.584593] [<c04c3858>] (kernel_init_freeable+0xec/0x1b4) from [<c0389af0>] (kernel_init+0x8/0xe4) > [ 0.593906] [<c0389af0>] (kernel_init+0x8/0xe4) from [<c0009448>] (ret_from_fork+0x14/0x2c) Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 263 bytes --] ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: SELinux + ubifs: possible circular locking dependency 2013-02-13 14:37 ` Marc Kleine-Budde @ 2013-02-14 6:36 ` Artem Bityutskiy 2013-02-14 7:15 ` Artem Bityutskiy 1 sibling, 0 replies; 6+ messages in thread From: Artem Bityutskiy @ 2013-02-14 6:36 UTC (permalink / raw) To: Marc Kleine-Budde Cc: linux-mtd, linux-security-module, LKML, kernel@pengutronix.de On Wed, 2013-02-13 at 15:37 +0100, Marc Kleine-Budde wrote: > > + lockdep_set_class(&isec->lock, inode->i_sb->s_type->i_mutex_key); > > So I added an "&", so that the line looks like that: Yeah, I did not compile it, and for the deadlock of course I have to add own class for isec->lock in the fstype structure. I'll try to come up with another patch. Thanks! -- Best Regards, Artem Bityutskiy ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: SELinux + ubifs: possible circular locking dependency 2013-02-13 14:37 ` Marc Kleine-Budde 2013-02-14 6:36 ` Artem Bityutskiy @ 2013-02-14 7:15 ` Artem Bityutskiy 2013-02-14 11:56 ` Marc Kleine-Budde 1 sibling, 1 reply; 6+ messages in thread From: Artem Bityutskiy @ 2013-02-14 7:15 UTC (permalink / raw) To: Marc Kleine-Budde Cc: linux-mtd, linux-security-module, LKML, kernel@pengutronix.de [-- Attachment #1: Type: text/plain, Size: 11110 bytes --] Mark, how about this one? I compiled it and ran on my fedora 16 with SElinux enabled, no obvious issues. >From a19350097200570571aa522afebb96b34db534f4 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Date: Thu, 14 Feb 2013 09:07:36 +0200 Subject: [PATCH] selinux: do not confuse lockdep Selinux has per-inode mutexes called 'isec->lock', and they are initialized in the same place, which makes lockdep treat all of the them as if they were identical. However, locking rules may be a little bit different depending on the file-system, so we should put these locks to separate classes, just like we do for 'i_mutex'. Namely, we should put them to per-FS type classes, which is exactly what this patch does. The problem this patch intends to fix is a strange lockdep warning, which I, frankly speaking, do not really understand, but I believe the root-cause should be fixed by this patch. Look at the stacktrace #4: here we have 'debugfs_create_dir()' [ 5.390312] ====================================================== [ 5.396500] [ INFO: possible circular locking dependency detected ] [ 5.402781] 3.8.0-rc6-00005-g4f7e39d #49 Not tainted [ 5.407750] ------------------------------------------------------- [ 5.414031] systemd/1 is trying to acquire lock: [ 5.418656] (&c->tnc_mutex){+.+...}, at: [<c01552d0>] ubifs_tnc_locate+0x30/0x198 [ 5.426343] [ 5.426343] but task is already holding lock: [ 5.432218] (&isec->lock){+.+.+.}, at: [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 5.440375] [ 5.440375] which lock already depends on the new lock. [ 5.440375] [ 5.448593] [ 5.448593] the existing dependency chain (in reverse order) is: [ 5.456093] -> #4 (&isec->lock){+.+.+.}: [ 5.460250] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.465437] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.471125] [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 5.477437] [<c0189bd8>] security_d_instantiate+0x1c/0x34 [ 5.483500] [<c017a614>] debugfs_mknod.part.15.constprop.18+0x94/0x128 [ 5.490656] [<c017a858>] __create_file+0x1b0/0x25c [ 5.496093] [<c017a98c>] debugfs_create_dir+0x1c/0x28 [ 5.501781] [<c0491ce8>] pinctrl_init+0x1c/0xd0 [ 5.506968] [<c0008900>] do_one_initcall+0x108/0x17c [ 5.512593] [<c0483858>] kernel_init_freeable+0xec/0x1b4 [ 5.518562] [<c034f398>] kernel_init+0x8/0xe4 [ 5.523562] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.528812] -> #3 (&sb->s_type->i_mutex_key#2){+.+.+.}: [ 5.534312] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.539468] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.545187] [<c017a6f8>] __create_file+0x50/0x25c [ 5.550531] [<c017a98c>] debugfs_create_dir+0x1c/0x28 [ 5.556218] [<c026cfc4>] clk_debug_create_subtree+0x1c/0x108 [ 5.562500] [<c0495bfc>] clk_debug_init+0x68/0xc0 [ 5.567875] [<c0008900>] do_one_initcall+0x108/0x17c [ 5.573468] [<c0483858>] kernel_init_freeable+0xec/0x1b4 [ 5.579437] [<c034f398>] kernel_init+0x8/0xe4 [ 5.584437] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.589687] -> #2 (prepare_lock){+.+.+.}: [ 5.593937] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.599125] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.604812] [<c026d400>] clk_prepare+0x18/0x38 [ 5.609906] [<c023a2f8>] __gpmi_enable_clk+0x30/0xb0 [ 5.615531] [<c023a7bc>] gpmi_begin+0x18/0x530 [ 5.620625] [<c0239244>] gpmi_select_chip+0x3c/0x54 [ 5.626156] [<c02341ac>] nand_do_read_ops+0x7c/0x3e4 [ 5.631750] [<c023483c>] nand_read+0x50/0x74 [ 5.636656] [<c02198e4>] part_read+0x5c/0xa4 [ 5.641593] [<c0217404>] mtd_read+0x84/0xb8 [ 5.646406] [<c02450cc>] ubi_io_read+0xa0/0x2c0 [ 5.651593] [<c0242640>] ubi_eba_read_leb+0x190/0x424 [ 5.657281] [<c0241b18>] ubi_leb_read+0xac/0x120 [ 5.662562] [<c01503e4>] ubifs_leb_read+0x28/0x8c [ 5.667906] [<c0151f74>] ubifs_read_node+0x98/0x2a0 [ 5.673437] [<c014e780>] ubifs_read_sb_node+0x54/0x78 [ 5.679125] [<c014f444>] ubifs_read_superblock+0xc60/0x163c [ 5.685343] [<c014d64c>] ubifs_mount+0x800/0x171c [ 5.690687] [<c00b5740>] mount_fs+0x44/0x184 [ 5.695593] [<c00cd7ec>] vfs_kern_mount+0x4c/0xc0 [ 5.700968] [<c00cf394>] do_mount+0x18c/0x8d0 [ 5.705968] [<c00cfb5c>] sys_mount+0x84/0xb8 [ 5.710875] [<c0483bc8>] mount_block_root+0x118/0x258 [ 5.716562] [<c0483eac>] prepare_namespace+0x8c/0x17c [ 5.722281] [<c034f398>] kernel_init+0x8/0xe4 [ 5.727281] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.732531] -> #1 (&le->mutex){++++..}: [ 5.736625] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.741812] [<c0356468>] down_read+0x40/0x54 [ 5.746718] [<c02424e4>] ubi_eba_read_leb+0x34/0x424 [ 5.752312] [<c0241b18>] ubi_leb_read+0xac/0x120 [ 5.757562] [<c01503e4>] ubifs_leb_read+0x28/0x8c [ 5.762937] [<c0151f74>] ubifs_read_node+0x98/0x2a0 [ 5.768437] [<c016edc0>] ubifs_load_znode+0x88/0x560 [ 5.774062] [<c0155254>] ubifs_lookup_level0+0x190/0x1dc [ 5.780031] [<c01552e4>] ubifs_tnc_locate+0x44/0x198 [ 5.785656] [<c014c614>] ubifs_iget+0x6c/0x8a4 [ 5.790718] [<c014da64>] ubifs_mount+0xc18/0x171c [ 5.796093] [<c00b5740>] mount_fs+0x44/0x184 [ 5.801000] [<c00cd7ec>] vfs_kern_mount+0x4c/0xc0 [ 5.806343] [<c00cf394>] do_mount+0x18c/0x8d0 [ 5.811343] [<c00cfb5c>] sys_mount+0x84/0xb8 [ 5.816250] [<c0483bc8>] mount_block_root+0x118/0x258 [ 5.821968] [<c0483eac>] prepare_namespace+0x8c/0x17c [ 5.827656] [<c034f398>] kernel_init+0x8/0xe4 [ 5.832656] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.837906] -> #0 (&c->tnc_mutex){+.+...}: [ 5.842250] [<c004de48>] __lock_acquire+0x14ec/0x1b08 [ 5.847968] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.853125] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.858812] [<c01552d0>] ubifs_tnc_locate+0x30/0x198 [ 5.864437] [<c0155a48>] ubifs_tnc_lookup_nm+0x28/0x150 [ 5.870312] [<c016fc18>] ubifs_getxattr+0xc0/0x254 [ 5.875750] [<c018e468>] inode_doinit_with_dentry+0x25c/0x55c [ 5.882125] [<c018f1a8>] sb_finish_set_opts+0xa4/0x21c [ 5.887906] [<c019055c>] selinux_set_mnt_opts+0x2ec/0x4b8 [ 5.893968] [<c01907dc>] superblock_doinit+0xb4/0xc0 [ 5.899562] [<c00b51f4>] iterate_supers+0xb4/0xdc [ 5.904906] [<c01a02e8>] security_load_policy+0x248/0x3c4 [ 5.910968] [<c0194994>] sel_write_load+0x9c/0x6a0 [ 5.916406] [<c00b2148>] vfs_write+0xa0/0x17c [ 5.921406] [<c00b2450>] sys_write+0x3c/0x70 [ 5.926343] [<c00093a0>] ret_fast_syscall+0x0/0x38 [ 5.931781] [ 5.931781] other info that might help us debug this: [ 5.931781] [ 5.939781] Chain exists of: &c->tnc_mutex --> &sb->s_type->i_mutex_key#2 --> &isec->lock [ 5.948500] Possible unsafe locking scenario: [ 5.948500] [ 5.954437] CPU0 CPU1 [ 5.958968] ---- ---- [ 5.963500] lock(&isec->lock); [ 5.966781] lock(&sb->s_type->i_mutex_key#2); [ 5.973843] lock(&isec->lock); [ 5.979625] lock(&c->tnc_mutex); [ 5.983062] [ 5.983062] *** DEADLOCK *** [ 5.983062] [ 5.989000] 4 locks held by systemd/1: [ 5.992781] #0: (sel_mutex){+.+.+.}, at: [<c0194918>] sel_write_load+0x20/0x6a0 [ 6.000343] #1: (&type->s_umount_key#26){.+.+..}, at: [<c00b51d0>] iterate_supers+0x90/0xdc [ 6.008968] #2: (&sbsec->lock){+.+.+.}, at: [<c01902d4>] selinux_set_mnt_opts+0x64/0x4b8 [ 6.017343] #3: (&isec->lock){+.+.+.}, at: [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 6.025937] [ 6.025937] stack backtrace: [ 6.030375] [<c000d0f0>] (unwind_backtrace+0x0/0xf0) from [<c0351a2c>] (print_circular_bug+0x25c/0x2a8) [ 6.039843] [<c0351a2c>] (print_circular_bug+0x25c/0x2a8) from [<c004de48>] (__lock_acquire+0x14ec/0x1b08) [ 6.049531] [<c004de48>] (__lock_acquire+0x14ec/0x1b08) from [<c004e8e8>] (lock_acquire+0x64/0x78) [ 6.058531] [<c004e8e8>] (lock_acquire+0x64/0x78) from [<c0355d5c>] (mutex_lock_nested+0x5c/0x2ec) [ 6.067531] [<c0355d5c>] (mutex_lock_nested+0x5c/0x2ec) from [<c01552d0>] (ubifs_tnc_locate+0x30/0x198) [ 6.076968] [<c01552d0>] (ubifs_tnc_locate+0x30/0x198) from [<c0155a48>] (ubifs_tnc_lookup_nm+0x28/0x150) [ 6.086593] [<c0155a48>] (ubifs_tnc_lookup_nm+0x28/0x150) from [<c016fc18>] (ubifs_getxattr+0xc0/0x254) [ 6.096031] [<c016fc18>] (ubifs_getxattr+0xc0/0x254) from [<c018e468>] (inode_doinit_with_dentry+0x25c/0x55c) [ 6.105968] [<c018e468>] (inode_doinit_with_dentry+0x25c/0x55c) from [<c018f1a8>] (sb_finish_set_opts+0xa4/0x21c) [ 6.116281] [<c018f1a8>] (sb_finish_set_opts+0xa4/0x21c) from [<c019055c>] (selinux_set_mnt_opts+0x2ec/0x4b8) [ 6.126218] [<c019055c>] (selinux_set_mnt_opts+0x2ec/0x4b8) from [<c01907dc>] (superblock_doinit+0xb4/0xc0) [ 6.136000] [<c01907dc>] (superblock_doinit+0xb4/0xc0) from [<c00b51f4>] (iterate_supers+0xb4/0xdc) [ 6.145093] [<c00b51f4>] (iterate_supers+0xb4/0xdc) from [<c01a02e8>] (security_load_policy+0x248/0x3c4) [ 6.154625] [<c01a02e8>] (security_load_policy+0x248/0x3c4) from [<c0194994>] (sel_write_load+0x9c/0x6a0) [ 6.164218] [<c0194994>] (sel_write_load+0x9c/0x6a0) from [<c00b2148>] (vfs_write+0xa0/0x17c) [ 6.172781] [<c00b2148>] (vfs_write+0xa0/0x17c) from [<c00b2450>] (sys_write+0x3c/0x70) [ 6.180843] [<c00b2450>] (sys_write+0x3c/0x70) from [<c00093a0>] (ret_fast_syscall+0x0/0x38) Reported-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> --- include/linux/fs.h | 1 + security/selinux/hooks.c | 2 ++ 2 files changed, 3 insertions(+), 0 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 7617ee0..ccd49e1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1824,6 +1824,7 @@ struct file_system_type { struct lock_class_key i_lock_key; struct lock_class_key i_mutex_key; struct lock_class_key i_mutex_dir_key; + struct lock_class_key i_security_lock_key; }; extern struct dentry *mount_ns(struct file_system_type *fs_type, int flags, diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ef26e96..13ccbb0 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -207,6 +207,8 @@ static int inode_alloc_security(struct inode *inode) return -ENOMEM; mutex_init(&isec->lock); + lockdep_set_class(&isec->lock, + &inode->i_sb->s_type->i_security_lock_key); INIT_LIST_HEAD(&isec->list); isec->inode = inode; isec->sid = SECINITSID_UNLABELED; -- 1.7.7.6 -- Best Regards, Artem Bityutskiy [-- Attachment #2: 0001-selinux-do-not-confuse-lockdep.patch --] [-- Type: text/x-patch, Size: 10969 bytes --] >From a19350097200570571aa522afebb96b34db534f4 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Date: Thu, 14 Feb 2013 09:07:36 +0200 Subject: [PATCH] selinux: do not confuse lockdep Selinux has per-inode mutexes called 'isec->lock', and they are initialized in the same place, which makes lockdep treat all of the them as if they were identical. However, locking rules may be a little bit different depending on the file-system, so we should put these locks to separate classes, just like we do for 'i_mutex'. Namely, we should put them to per-FS type classes, which is exactly what this patch does. The problem this patch intends to fix is a strange lockdep warning, which I, frankly speaking, do not really understand, but I believe the root-cause should be fixed by this patch. Look at the stacktrace #4: here we have 'debugfs_create_dir()' [ 5.390312] ====================================================== [ 5.396500] [ INFO: possible circular locking dependency detected ] [ 5.402781] 3.8.0-rc6-00005-g4f7e39d #49 Not tainted [ 5.407750] ------------------------------------------------------- [ 5.414031] systemd/1 is trying to acquire lock: [ 5.418656] (&c->tnc_mutex){+.+...}, at: [<c01552d0>] ubifs_tnc_locate+0x30/0x198 [ 5.426343] [ 5.426343] but task is already holding lock: [ 5.432218] (&isec->lock){+.+.+.}, at: [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 5.440375] [ 5.440375] which lock already depends on the new lock. [ 5.440375] [ 5.448593] [ 5.448593] the existing dependency chain (in reverse order) is: [ 5.456093] -> #4 (&isec->lock){+.+.+.}: [ 5.460250] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.465437] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.471125] [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 5.477437] [<c0189bd8>] security_d_instantiate+0x1c/0x34 [ 5.483500] [<c017a614>] debugfs_mknod.part.15.constprop.18+0x94/0x128 [ 5.490656] [<c017a858>] __create_file+0x1b0/0x25c [ 5.496093] [<c017a98c>] debugfs_create_dir+0x1c/0x28 [ 5.501781] [<c0491ce8>] pinctrl_init+0x1c/0xd0 [ 5.506968] [<c0008900>] do_one_initcall+0x108/0x17c [ 5.512593] [<c0483858>] kernel_init_freeable+0xec/0x1b4 [ 5.518562] [<c034f398>] kernel_init+0x8/0xe4 [ 5.523562] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.528812] -> #3 (&sb->s_type->i_mutex_key#2){+.+.+.}: [ 5.534312] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.539468] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.545187] [<c017a6f8>] __create_file+0x50/0x25c [ 5.550531] [<c017a98c>] debugfs_create_dir+0x1c/0x28 [ 5.556218] [<c026cfc4>] clk_debug_create_subtree+0x1c/0x108 [ 5.562500] [<c0495bfc>] clk_debug_init+0x68/0xc0 [ 5.567875] [<c0008900>] do_one_initcall+0x108/0x17c [ 5.573468] [<c0483858>] kernel_init_freeable+0xec/0x1b4 [ 5.579437] [<c034f398>] kernel_init+0x8/0xe4 [ 5.584437] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.589687] -> #2 (prepare_lock){+.+.+.}: [ 5.593937] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.599125] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.604812] [<c026d400>] clk_prepare+0x18/0x38 [ 5.609906] [<c023a2f8>] __gpmi_enable_clk+0x30/0xb0 [ 5.615531] [<c023a7bc>] gpmi_begin+0x18/0x530 [ 5.620625] [<c0239244>] gpmi_select_chip+0x3c/0x54 [ 5.626156] [<c02341ac>] nand_do_read_ops+0x7c/0x3e4 [ 5.631750] [<c023483c>] nand_read+0x50/0x74 [ 5.636656] [<c02198e4>] part_read+0x5c/0xa4 [ 5.641593] [<c0217404>] mtd_read+0x84/0xb8 [ 5.646406] [<c02450cc>] ubi_io_read+0xa0/0x2c0 [ 5.651593] [<c0242640>] ubi_eba_read_leb+0x190/0x424 [ 5.657281] [<c0241b18>] ubi_leb_read+0xac/0x120 [ 5.662562] [<c01503e4>] ubifs_leb_read+0x28/0x8c [ 5.667906] [<c0151f74>] ubifs_read_node+0x98/0x2a0 [ 5.673437] [<c014e780>] ubifs_read_sb_node+0x54/0x78 [ 5.679125] [<c014f444>] ubifs_read_superblock+0xc60/0x163c [ 5.685343] [<c014d64c>] ubifs_mount+0x800/0x171c [ 5.690687] [<c00b5740>] mount_fs+0x44/0x184 [ 5.695593] [<c00cd7ec>] vfs_kern_mount+0x4c/0xc0 [ 5.700968] [<c00cf394>] do_mount+0x18c/0x8d0 [ 5.705968] [<c00cfb5c>] sys_mount+0x84/0xb8 [ 5.710875] [<c0483bc8>] mount_block_root+0x118/0x258 [ 5.716562] [<c0483eac>] prepare_namespace+0x8c/0x17c [ 5.722281] [<c034f398>] kernel_init+0x8/0xe4 [ 5.727281] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.732531] -> #1 (&le->mutex){++++..}: [ 5.736625] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.741812] [<c0356468>] down_read+0x40/0x54 [ 5.746718] [<c02424e4>] ubi_eba_read_leb+0x34/0x424 [ 5.752312] [<c0241b18>] ubi_leb_read+0xac/0x120 [ 5.757562] [<c01503e4>] ubifs_leb_read+0x28/0x8c [ 5.762937] [<c0151f74>] ubifs_read_node+0x98/0x2a0 [ 5.768437] [<c016edc0>] ubifs_load_znode+0x88/0x560 [ 5.774062] [<c0155254>] ubifs_lookup_level0+0x190/0x1dc [ 5.780031] [<c01552e4>] ubifs_tnc_locate+0x44/0x198 [ 5.785656] [<c014c614>] ubifs_iget+0x6c/0x8a4 [ 5.790718] [<c014da64>] ubifs_mount+0xc18/0x171c [ 5.796093] [<c00b5740>] mount_fs+0x44/0x184 [ 5.801000] [<c00cd7ec>] vfs_kern_mount+0x4c/0xc0 [ 5.806343] [<c00cf394>] do_mount+0x18c/0x8d0 [ 5.811343] [<c00cfb5c>] sys_mount+0x84/0xb8 [ 5.816250] [<c0483bc8>] mount_block_root+0x118/0x258 [ 5.821968] [<c0483eac>] prepare_namespace+0x8c/0x17c [ 5.827656] [<c034f398>] kernel_init+0x8/0xe4 [ 5.832656] [<c0009448>] ret_from_fork+0x14/0x2c [ 5.837906] -> #0 (&c->tnc_mutex){+.+...}: [ 5.842250] [<c004de48>] __lock_acquire+0x14ec/0x1b08 [ 5.847968] [<c004e8e8>] lock_acquire+0x64/0x78 [ 5.853125] [<c0355d5c>] mutex_lock_nested+0x5c/0x2ec [ 5.858812] [<c01552d0>] ubifs_tnc_locate+0x30/0x198 [ 5.864437] [<c0155a48>] ubifs_tnc_lookup_nm+0x28/0x150 [ 5.870312] [<c016fc18>] ubifs_getxattr+0xc0/0x254 [ 5.875750] [<c018e468>] inode_doinit_with_dentry+0x25c/0x55c [ 5.882125] [<c018f1a8>] sb_finish_set_opts+0xa4/0x21c [ 5.887906] [<c019055c>] selinux_set_mnt_opts+0x2ec/0x4b8 [ 5.893968] [<c01907dc>] superblock_doinit+0xb4/0xc0 [ 5.899562] [<c00b51f4>] iterate_supers+0xb4/0xdc [ 5.904906] [<c01a02e8>] security_load_policy+0x248/0x3c4 [ 5.910968] [<c0194994>] sel_write_load+0x9c/0x6a0 [ 5.916406] [<c00b2148>] vfs_write+0xa0/0x17c [ 5.921406] [<c00b2450>] sys_write+0x3c/0x70 [ 5.926343] [<c00093a0>] ret_fast_syscall+0x0/0x38 [ 5.931781] [ 5.931781] other info that might help us debug this: [ 5.931781] [ 5.939781] Chain exists of: &c->tnc_mutex --> &sb->s_type->i_mutex_key#2 --> &isec->lock [ 5.948500] Possible unsafe locking scenario: [ 5.948500] [ 5.954437] CPU0 CPU1 [ 5.958968] ---- ---- [ 5.963500] lock(&isec->lock); [ 5.966781] lock(&sb->s_type->i_mutex_key#2); [ 5.973843] lock(&isec->lock); [ 5.979625] lock(&c->tnc_mutex); [ 5.983062] [ 5.983062] *** DEADLOCK *** [ 5.983062] [ 5.989000] 4 locks held by systemd/1: [ 5.992781] #0: (sel_mutex){+.+.+.}, at: [<c0194918>] sel_write_load+0x20/0x6a0 [ 6.000343] #1: (&type->s_umount_key#26){.+.+..}, at: [<c00b51d0>] iterate_supers+0x90/0xdc [ 6.008968] #2: (&sbsec->lock){+.+.+.}, at: [<c01902d4>] selinux_set_mnt_opts+0x64/0x4b8 [ 6.017343] #3: (&isec->lock){+.+.+.}, at: [<c018e298>] inode_doinit_with_dentry+0x8c/0x55c [ 6.025937] [ 6.025937] stack backtrace: [ 6.030375] [<c000d0f0>] (unwind_backtrace+0x0/0xf0) from [<c0351a2c>] (print_circular_bug+0x25c/0x2a8) [ 6.039843] [<c0351a2c>] (print_circular_bug+0x25c/0x2a8) from [<c004de48>] (__lock_acquire+0x14ec/0x1b08) [ 6.049531] [<c004de48>] (__lock_acquire+0x14ec/0x1b08) from [<c004e8e8>] (lock_acquire+0x64/0x78) [ 6.058531] [<c004e8e8>] (lock_acquire+0x64/0x78) from [<c0355d5c>] (mutex_lock_nested+0x5c/0x2ec) [ 6.067531] [<c0355d5c>] (mutex_lock_nested+0x5c/0x2ec) from [<c01552d0>] (ubifs_tnc_locate+0x30/0x198) [ 6.076968] [<c01552d0>] (ubifs_tnc_locate+0x30/0x198) from [<c0155a48>] (ubifs_tnc_lookup_nm+0x28/0x150) [ 6.086593] [<c0155a48>] (ubifs_tnc_lookup_nm+0x28/0x150) from [<c016fc18>] (ubifs_getxattr+0xc0/0x254) [ 6.096031] [<c016fc18>] (ubifs_getxattr+0xc0/0x254) from [<c018e468>] (inode_doinit_with_dentry+0x25c/0x55c) [ 6.105968] [<c018e468>] (inode_doinit_with_dentry+0x25c/0x55c) from [<c018f1a8>] (sb_finish_set_opts+0xa4/0x21c) [ 6.116281] [<c018f1a8>] (sb_finish_set_opts+0xa4/0x21c) from [<c019055c>] (selinux_set_mnt_opts+0x2ec/0x4b8) [ 6.126218] [<c019055c>] (selinux_set_mnt_opts+0x2ec/0x4b8) from [<c01907dc>] (superblock_doinit+0xb4/0xc0) [ 6.136000] [<c01907dc>] (superblock_doinit+0xb4/0xc0) from [<c00b51f4>] (iterate_supers+0xb4/0xdc) [ 6.145093] [<c00b51f4>] (iterate_supers+0xb4/0xdc) from [<c01a02e8>] (security_load_policy+0x248/0x3c4) [ 6.154625] [<c01a02e8>] (security_load_policy+0x248/0x3c4) from [<c0194994>] (sel_write_load+0x9c/0x6a0) [ 6.164218] [<c0194994>] (sel_write_load+0x9c/0x6a0) from [<c00b2148>] (vfs_write+0xa0/0x17c) [ 6.172781] [<c00b2148>] (vfs_write+0xa0/0x17c) from [<c00b2450>] (sys_write+0x3c/0x70) [ 6.180843] [<c00b2450>] (sys_write+0x3c/0x70) from [<c00093a0>] (ret_fast_syscall+0x0/0x38) Reported-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> --- include/linux/fs.h | 1 + security/selinux/hooks.c | 2 ++ 2 files changed, 3 insertions(+), 0 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 7617ee0..ccd49e1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1824,6 +1824,7 @@ struct file_system_type { struct lock_class_key i_lock_key; struct lock_class_key i_mutex_key; struct lock_class_key i_mutex_dir_key; + struct lock_class_key i_security_lock_key; }; extern struct dentry *mount_ns(struct file_system_type *fs_type, int flags, diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ef26e96..13ccbb0 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -207,6 +207,8 @@ static int inode_alloc_security(struct inode *inode) return -ENOMEM; mutex_init(&isec->lock); + lockdep_set_class(&isec->lock, + &inode->i_sb->s_type->i_security_lock_key); INIT_LIST_HEAD(&isec->list); isec->inode = inode; isec->sid = SECINITSID_UNLABELED; -- 1.7.7.6 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: SELinux + ubifs: possible circular locking dependency 2013-02-14 7:15 ` Artem Bityutskiy @ 2013-02-14 11:56 ` Marc Kleine-Budde 0 siblings, 0 replies; 6+ messages in thread From: Marc Kleine-Budde @ 2013-02-14 11:56 UTC (permalink / raw) To: dedekind1; +Cc: linux-mtd, linux-security-module, LKML, kernel@pengutronix.de [-- Attachment #1: Type: text/plain, Size: 9946 bytes --] On 02/14/2013 08:15 AM, Artem Bityutskiy wrote: > Mark, how about this one? I compiled it and ran on my fedora 16 with > SElinux enabled, no obvious issues. > > From a19350097200570571aa522afebb96b34db534f4 Mon Sep 17 00:00:00 2001 > From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> > Date: Thu, 14 Feb 2013 09:07:36 +0200 > Subject: [PATCH] selinux: do not confuse lockdep > > Selinux has per-inode mutexes called 'isec->lock', and they are initialized in > the same place, which makes lockdep treat all of the them as if they were > identical. However, locking rules may be a little bit different depending on > the file-system, so we should put these locks to separate classes, just like we > do for 'i_mutex'. Namely, we should put them to per-FS type classes, which is > exactly what this patch does. > > The problem this patch intends to fix is a strange lockdep warning, which I, > frankly speaking, do not really understand, but I believe the root-cause should > be fixed by this patch. Thanks, this works with mainline, but not with my xattr patch series applied. I get this warnings: > [ 13.659593] ====================================================== > [ 13.665781] [ INFO: possible circular locking dependency detected ] > [ 13.672062] 3.8.0-rc7-00011-gd50987e #113 Not tainted > [ 13.677125] ------------------------------------------------------- > [ 13.683406] touch/81 is trying to acquire lock: > [ 13.687968] (&sb->s_type->i_mutex_key#10){+.+...}, at: [<c0178330>] ubifs_init_security+0x24/0x5c > [ 13.697031] > [ 13.697031] but task is already holding lock: > [ 13.702906] (&ui->ui_mutex){+.+...}, at: [<c0152a98>] ubifs_create+0xb4/0x1ec > [ 13.710218] > [ 13.710218] which lock already depends on the new lock. > [ 13.710218] > [ 13.718406] > [ 13.718406] the existing dependency chain (in reverse order) is: > [ 13.725906] > -> #1 (&ui->ui_mutex){+.+...}: > [ 13.730250] [<c00548f0>] lock_acquire+0x64/0x78 > [ 13.735437] [<c035ea74>] mutex_lock_nested+0x5c/0x2ec > [ 13.741156] [<c014f510>] ubifs_write_begin+0x314/0x500 > [ 13.746937] [<c0084998>] generic_file_buffered_write+0x1b4/0x288 > [ 13.753625] [<c0086704>] __generic_file_aio_write+0x1bc/0x434 > [ 13.760000] [<c00869e4>] generic_file_aio_write+0x68/0xd8 > [ 13.766031] [<c014eaec>] ubifs_aio_write+0xf8/0x194 > [ 13.771562] [<c00b8994>] do_sync_write+0x94/0xc8 > [ 13.776843] [<c00b9148>] vfs_write+0xa0/0x17c > [ 13.781843] [<c00b9450>] sys_write+0x3c/0x70 > [ 13.786750] [<c000e400>] ret_fast_syscall+0x0/0x38 > [ 13.792187] > -> #0 (&sb->s_type->i_mutex_key#10){+.+...}: > [ 13.797781] [<c0053e50>] __lock_acquire+0x14ec/0x1b08 > [ 13.803468] [<c00548f0>] lock_acquire+0x64/0x78 > [ 13.808625] [<c035ea74>] mutex_lock_nested+0x5c/0x2ec > [ 13.814343] [<c0178330>] ubifs_init_security+0x24/0x5c > [ 13.820125] [<c0152b10>] ubifs_create+0x12c/0x1ec > [ 13.825468] [<c00c40a0>] vfs_create+0xa8/0x118 > [ 13.830562] [<c00c6594>] do_last+0x930/0xd4c > [ 13.835468] [<c00c6a58>] path_openat+0xa8/0x4b8 > [ 13.840625] [<c00c7168>] do_filp_open+0x2c/0x80 > [ 13.845812] [<c00b86e4>] do_sys_open+0xe4/0x170 > [ 13.850968] [<c000e400>] ret_fast_syscall+0x0/0x38 > [ 13.856406] > [ 13.856406] other info that might help us debug this: > [ 13.856406] > [ 13.864437] Possible unsafe locking scenario: > [ 13.864437] > [ 13.870375] CPU0 CPU1 > [ 13.874906] ---- ---- > [ 13.879468] lock(&ui->ui_mutex); > [ 13.882906] lock(&sb->s_type->i_mutex_key#10); > [ 13.890093] lock(&ui->ui_mutex); > [ 13.896031] lock(&sb->s_type->i_mutex_key#10); > [ 13.900718] > [ 13.900718] *** DEADLOCK *** > [ 13.900718] > [ 13.906656] 3 locks held by touch/81: > [ 13.910312] #0: (sb_writers#3){.+.+.+}, at: [<c00d4e68>] mnt_want_write+0x18/0x3c > [ 13.918093] #1: (&type->i_mutex_dir_key){+.+.+.}, at: [<c00c5fcc>] do_last+0x368/0xd4c > [ 13.926281] #2: (&ui->ui_mutex){+.+...}, at: [<c0152a98>] ubifs_create+0xb4/0x1ec > [ 13.934031] > [ 13.934031] stack backtrace: > [ 13.938468] [<c00124f0>] (unwind_backtrace+0x0/0xf0) from [<c035a670>] (print_circular_bug+0x25c/0x2a8) > [ 13.947906] [<c035a670>] (print_circular_bug+0x25c/0x2a8) from [<c0053e50>] (__lock_acquire+0x14ec/0x1b08) > [ 13.957593] [<c0053e50>] (__lock_acquire+0x14ec/0x1b08) from [<c00548f0>] (lock_acquire+0x64/0x78) > [ 13.966593] [<c00548f0>] (lock_acquire+0x64/0x78) from [<c035ea74>] (mutex_lock_nested+0x5c/0x2ec) > [ 13.975593] [<c035ea74>] (mutex_lock_nested+0x5c/0x2ec) from [<c0178330>] (ubifs_init_security+0x24/0x5c) > [ 13.985187] [<c0178330>] (ubifs_init_security+0x24/0x5c) from [<c0152b10>] (ubifs_create+0x12c/0x1ec) > [ 13.994437] [<c0152b10>] (ubifs_create+0x12c/0x1ec) from [<c00c40a0>] (vfs_create+0xa8/0x118) > [ 14.003000] [<c00c40a0>] (vfs_create+0xa8/0x118) from [<c00c6594>] (do_last+0x930/0xd4c) > [ 14.011125] [<c00c6594>] (do_last+0x930/0xd4c) from [<c00c6a58>] (path_openat+0xa8/0x4b8) > [ 14.019343] [<c00c6a58>] (path_openat+0xa8/0x4b8) from [<c00c7168>] (do_filp_open+0x2c/0x80) > [ 14.027812] [<c00c7168>] (do_filp_open+0x2c/0x80) from [<c00b86e4>] (do_sys_open+0xe4/0x170) > [ 14.036281] [<c00b86e4>] (do_sys_open+0xe4/0x170) from [<c000e400>] (ret_fast_syscall+0x0/0x38) or this: > [ 54.994687] > [ 54.996218] ====================================================== > [ 55.002437] [ INFO: possible circular locking dependency detected ] > [ 55.008718] 3.8.0-rc7-00011-gd50987e #113 Not tainted > [ 55.013781] ------------------------------------------------------- > [ 55.020062] semodule/427 is trying to acquire lock: > [ 55.024937] (&sb->s_type->i_mutex_key#12){+.+.+.}, at: [<c0178330>] ubifs_init_security+0x24/0x5c > [ 55.034031] > [ 55.034031] but task is already holding lock: > [ 55.039875] (&ui->ui_mutex){+.+...}, at: [<c0152614>] ubifs_mkdir+0x98/0x204 > [ 55.047125] > [ 55.047125] which lock already depends on the new lock. > [ 55.047125] > [ 55.055312] > [ 55.055312] the existing dependency chain (in reverse order) is: > [ 55.062812] > -> #1 (&ui->ui_mutex){+.+...}: > [ 55.067156] [<c00548f0>] lock_acquire+0x64/0x78 > [ 55.072343] [<c035ea74>] mutex_lock_nested+0x5c/0x2ec > [ 55.078031] [<c014ffb8>] ubifs_setattr+0x2c8/0x3f8 > [ 55.083500] [<c00d1b14>] notify_change+0x1dc/0x330 > [ 55.088937] [<c00b7838>] do_truncate+0x78/0x9c > [ 55.094031] [<c00c6318>] do_last+0x6b4/0xd4c > [ 55.098937] [<c00c6a58>] path_openat+0xa8/0x4b8 > [ 55.104125] [<c00c7168>] do_filp_open+0x2c/0x80 > [ 55.109281] [<c00b86e4>] do_sys_open+0xe4/0x170 > [ 55.114468] [<c000e400>] ret_fast_syscall+0x0/0x38 > [ 55.119906] > -> #0 (&sb->s_type->i_mutex_key#12){+.+.+.}: > [ 55.125468] [<c0053e50>] __lock_acquire+0x14ec/0x1b08 > [ 55.131187] [<c00548f0>] lock_acquire+0x64/0x78 > [ 55.136343] [<c035ea74>] mutex_lock_nested+0x5c/0x2ec > [ 55.142062] [<c0178330>] ubifs_init_security+0x24/0x5c > [ 55.147843] [<c01526b4>] ubifs_mkdir+0x138/0x204 > [ 55.153093] [<c00c3e50>] vfs_mkdir+0xb8/0x138 > [ 55.158093] [<c00c74bc>] sys_mkdirat+0x5c/0xb0 > [ 55.163187] [<c000e400>] ret_fast_syscall+0x0/0x38 > [ 55.168625] > [ 55.168625] other info that might help us debug this: > [ 55.168625] > [ 55.176625] Possible unsafe locking scenario: > [ 55.176625] > [ 55.182562] CPU0 CPU1 > [ 55.187125] ---- ---- > [ 55.191656] lock(&ui->ui_mutex); > [ 55.195093] lock(&sb->s_type->i_mutex_key#12); > [ 55.202281] lock(&ui->ui_mutex); > [ 55.208218] lock(&sb->s_type->i_mutex_key#12); > [ 55.212906] > [ 55.212906] *** DEADLOCK *** > [ 55.212906] > [ 55.218843] 3 locks held by semodule/427: > [ 55.222875] #0: (sb_writers#3){.+.+.+}, at: [<c00d4e68>] mnt_want_write+0x18/0x3c > [ 55.230656] #1: (&type->i_mutex_dir_key/1){+.+.+.}, at: [<c00c4ed0>] kern_path_create+0x6c/0x11c > [ 55.239718] #2: (&ui->ui_mutex){+.+...}, at: [<c0152614>] ubifs_mkdir+0x98/0x204 > [ 55.247375] > [ 55.247375] stack backtrace: > [ 55.251812] [<c00124f0>] (unwind_backtrace+0x0/0xf0) from [<c035a670>] (print_circular_bug+0x25c/0x2a8) > [ 55.261250] [<c035a670>] (print_circular_bug+0x25c/0x2a8) from [<c0053e50>] (__lock_acquire+0x14ec/0x1b08) > [ 55.270937] [<c0053e50>] (__lock_acquire+0x14ec/0x1b08) from [<c00548f0>] (lock_acquire+0x64/0x78) > [ 55.279937] [<c00548f0>] (lock_acquire+0x64/0x78) from [<c035ea74>] (mutex_lock_nested+0x5c/0x2ec) > [ 55.288937] [<c035ea74>] (mutex_lock_nested+0x5c/0x2ec) from [<c0178330>] (ubifs_init_security+0x24/0x5c) > [ 55.298531] [<c0178330>] (ubifs_init_security+0x24/0x5c) from [<c01526b4>] (ubifs_mkdir+0x138/0x204) > [ 55.307687] [<c01526b4>] (ubifs_mkdir+0x138/0x204) from [<c00c3e50>] (vfs_mkdir+0xb8/0x138) > [ 55.316062] [<c00c3e50>] (vfs_mkdir+0xb8/0x138) from [<c00c74bc>] (sys_mkdirat+0x5c/0xb0) > [ 55.324281] [<c00c74bc>] (sys_mkdirat+0x5c/0xb0) from [<c000e400>] (ret_fast_syscall+0x0/0x38) Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 263 bytes --] ^ permalink raw reply [flat|nested] 6+ messages in thread
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[not found] <51123C80.2050400@pengutronix.de>
2013-02-08 14:10 ` SELinux + ubifs: possible circular locking dependency Marc Kleine-Budde
2013-02-13 12:47 ` Artem Bityutskiy
2013-02-13 14:37 ` Marc Kleine-Budde
2013-02-14 6:36 ` Artem Bityutskiy
2013-02-14 7:15 ` Artem Bityutskiy
2013-02-14 11:56 ` Marc Kleine-Budde
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