diff mbox series

possible circular locking in kernfs_remove_by_name_ns/devinet_ioctl linux 6.0-rc3

Message ID 20220901122129.GA493609@francesco-nb.int.toradex.com (mailing list archive)
State RFC
Headers show
Series possible circular locking in kernfs_remove_by_name_ns/devinet_ioctl linux 6.0-rc3 | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Francesco Dolcini Sept. 1, 2022, 12:21 p.m. UTC 
Hello all,
I have this warning on linux 6.0-rc3, running on a ARM colibri-imx7.

[   21.629186] ======================================================
[   21.635418] WARNING: possible circular locking dependency detected
[   21.641646] 6.0.0-rc3 #7 Not tainted
[   21.645256] ------------------------------------------------------
[   21.651480] connmand/542 is trying to acquire lock:
[   21.656399] c2ce1d70 (kn->active#9){++++}-{0:0}, at: kernfs_remove_by_name_ns+0x50/0xa0
[   21.664516]
               but task is already holding lock:
[   21.670394] c17af6e0 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0xc8/0x870
[   21.677441]
               which lock already depends on the new lock.

[   21.685677]
               the existing dependency chain (in reverse order) is:
[   21.693230]
               -> #2 (rtnl_mutex){+.+.}-{3:3}:
[   21.698971]        __mutex_lock+0x88/0x1110
[   21.703208]        mutex_lock_killable_nested+0x1c/0x28
[   21.708487]        register_netdev+0xc/0x34
[   21.712721]        gether_register_netdev+0x38/0xb0
[   21.717654]        rndis_bind+0x22c/0x39c
[   21.721710]        usb_add_function+0x7c/0x1e4
[   21.726201]        configfs_composite_bind+0x1bc/0x370
[   21.731391]        gadget_bind_driver+0x9c/0x204
[   21.736059]        really_probe+0xd8/0x3dc
[   21.740201]        __driver_probe_device+0x94/0x200
[   21.745125]        driver_probe_device+0x2c/0xd0
[   21.749785]        __driver_attach+0xc0/0x18c
[   21.754184]        bus_for_each_dev+0x74/0xc0
[   21.758583]        bus_add_driver+0x164/0x218
[   21.762980]        driver_register+0x74/0x10c
[   21.767379]        usb_gadget_register_driver_owner+0x40/0xd4
[   21.773173]        gadget_dev_desc_UDC_store+0xbc/0xf0
[   21.778358]        configfs_write_iter+0xac/0x110
[   21.783110]        vfs_write+0x2d4/0x46c
[   21.787077]        ksys_write+0x60/0xec
[   21.790953]        ret_fast_syscall+0x0/0x1c
[   21.795265]        0xbeeb4b88
[   21.798266]
               -> #1 (udc_lock){+.+.}-{3:3}:
[   21.803824]        __mutex_lock+0x88/0x1110
[   21.808054]        mutex_lock_nested+0x1c/0x24
[   21.812540]        usb_udc_uevent+0x34/0xb0
[   21.816763]        dev_uevent+0x100/0x2dc
[   21.820812]        uevent_show+0x90/0x10c
[   21.824860]        dev_attr_show+0x18/0x48
[   21.828999]        sysfs_kf_seq_show+0x88/0x118
[   21.833573]        seq_read_iter+0x194/0x4bc
[   21.837885]        vfs_read+0x1a8/0x270
[   21.841762]        ksys_read+0x60/0xec
[   21.845550]        ret_fast_syscall+0x0/0x1c
[   21.849860]        0xbea98840
[   21.852857]
               -> #0 (kn->active#9){++++}-{0:0}:
[   21.858766]        __lock_acquire+0x1550/0x23c0
[   21.863344]        lock_acquire+0x108/0x37c
[   21.867570]        __kernfs_remove+0x294/0x368
[   21.872055]        kernfs_remove_by_name_ns+0x50/0xa0
[   21.877151]        device_del+0x178/0x454
[   21.881199]        device_unregister+0x20/0x64
[   21.885683]        wakeup_source_unregister.part.0+0x20/0x3c
[   21.891396]        device_wakeup_disable+0x48/0x58
[   21.896232]        fec_enet_open+0x2ec/0x36c
[   21.900547]        __dev_open+0xec/0x180
[   21.904512]        __dev_change_flags+0x164/0x1d4
[   21.909261]        dev_change_flags+0x14/0x44
[   21.913660]        devinet_ioctl+0x6c8/0x870
[   21.917971]        inet_ioctl+0x1c4/0x2b8
[   21.922019]        sock_ioctl+0x458/0x4fc
[   21.926072]        sys_ioctl+0xf4/0xe04
[   21.929948]        ret_fast_syscall+0x0/0x1c
[   21.934258]        0xbeeca960
[   21.937256]
               other info that might help us debug this:

[   21.945318] Chain exists of:
                 kn->active#9 --> udc_lock --> rtnl_mutex

[   21.954902]  Possible unsafe locking scenario:

[   21.960865]        CPU0                    CPU1
[   21.965430]        ----                    ----
[   21.969994]   lock(rtnl_mutex);
[   21.973174]                                lock(udc_lock);
[   21.978709]                                lock(rtnl_mutex);
[   21.984419]   lock(kn->active#9);
[   21.987779]
                *** DEADLOCK ***

[   21.993745] 1 lock held by connmand/542:
[   21.997704]  #0: c17af6e0 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0xc8/0x870
[   22.005191]
               stack backtrace:
[   22.009587] CPU: 0 PID: 542 Comm: connmand Not tainted 6.0.0-rc3 #7
[   22.015905] Hardware name: Freescale i.MX7 Dual (Device Tree)
[   22.021703]  unwind_backtrace from show_stack+0x10/0x14
[   22.026985]  show_stack from dump_stack_lvl+0x58/0x70
[   22.032088]  dump_stack_lvl from check_noncircular+0xf4/0x168
[   22.037891]  check_noncircular from check_prev_add+0xc4/0x15d8
[   22.043783]  check_prev_add from __lock_acquire+0x1550/0x23c0
[   22.049587]  __lock_acquire from lock_acquire+0x108/0x37c
[   22.055041]  lock_acquire from __kernfs_remove+0x294/0x368
[   22.060582]  __kernfs_remove from kernfs_remove_by_name_ns+0x50/0xa0
[   22.066991]  kernfs_remove_by_name_ns from device_del+0x178/0x454
[   22.073141]  device_del from device_unregister+0x20/0x64
[   22.078501]  device_unregister from wakeup_source_unregister.part.0+0x20/0x3c
[   22.085700]  wakeup_source_unregister.part.0 from device_wakeup_disable+0x48/0x58
[   22.093253]  device_wakeup_disable from fec_enet_open+0x2ec/0x36c
[   22.099408]  fec_enet_open from __dev_open+0xec/0x180
[   22.104514]  __dev_open from __dev_change_flags+0x164/0x1d4
[   22.110141]  __dev_change_flags from dev_change_flags+0x14/0x44
[   22.116117]  dev_change_flags from devinet_ioctl+0x6c8/0x870
[   22.121830]  devinet_ioctl from inet_ioctl+0x1c4/0x2b8
[   22.127017]  inet_ioctl from sock_ioctl+0x458/0x4fc
[   22.131946]  sock_ioctl from sys_ioctl+0xf4/0xe04
[   22.136701]  sys_ioctl from ret_fast_syscall+0x0/0x1c
[   22.141802] Exception stack(0xf1269fa8 to 0xf1269ff0)
[   22.146900] 9fa0:                   00000000 beeca984 00000010 00008914 beeca984 beeca978
[   22.155141] 9fc0: 00000000 beeca984 00000010 00000036 00000003 00001002 00000e94 beecab3c
[   22.163380] 9fe0: 00000036 beeca960 b6b58089 b6ad1ae6


The kernel configuration used is based on imx_v6_v7_defconfig with the
following changes:


I have not tried to bisect this yet, just probing if someone has already
some idea on this.

Francesco

Comments

Francesco Dolcini Sept. 1, 2022, 7:25 p.m. UTC | #1 
On Thu, Sep 01, 2022 at 02:21:29PM +0200, Francesco Dolcini wrote:
> [   21.629186] ======================================================
> [   21.635418] WARNING: possible circular locking dependency detected
> [   21.641646] 6.0.0-rc3 #7 Not tainted
> [   21.645256] ------------------------------------------------------
> [   21.651480] connmand/542 is trying to acquire lock:
> [   21.656399] c2ce1d70 (kn->active#9){++++}-{0:0}, at: kernfs_remove_by_name_ns+0x50/0xa0
> [   21.664516]
>                but task is already holding lock:
> [   21.670394] c17af6e0 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0xc8/0x870
> [   21.677441]
>                which lock already depends on the new lock.
...
> [   21.945318] Chain exists of:
>                  kn->active#9 --> udc_lock --> rtnl_mutex
> 
> [   21.954902]  Possible unsafe locking scenario:
> 
> [   21.960865]        CPU0                    CPU1
> [   21.965430]        ----                    ----
> [   21.969994]   lock(rtnl_mutex);
> [   21.973174]                                lock(udc_lock);
> [   21.978709]                                lock(rtnl_mutex);
> [   21.984419]   lock(kn->active#9);
> [   21.987779]
>                 *** DEADLOCK ***
> 
> [   21.993745] 1 lock held by connmand/542:
> [   21.997704]  #0: c17af6e0 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0xc8/0x870
> [   22.005191]
...
> I have not tried to bisect this yet, just probing if someone has already
> some idea on this.

Commit 2191c00855b0 ("USB: gadget: Fix use-after-free Read in usb_udc_uevent()")
introduced this, see
https://lore.kernel.org/all/20220901192204.GA2268599@francesco-nb.int.toradex.com/

Francesco
diff mbox series

Patch

--- original	2022-09-01 14:13:12.334642373 +0200
+++ new	2022-09-01 14:12:46.799096809 +0200
@@ -1 +1 @@ 
-CONFIG_KERNEL_LZO=y
+CONFIG_KERNEL_LZ4=y
@@ -18,5 +17,0 @@ 
-CONFIG_SOC_IMX31=y
-CONFIG_SOC_IMX35=y
-CONFIG_SOC_IMX50=y
-CONFIG_SOC_IMX51=y
-CONFIG_SOC_IMX53=y
@@ -24,3 +18,0 @@ 
-CONFIG_SOC_IMX6SL=y
-CONFIG_SOC_IMX6SLL=y
-CONFIG_SOC_IMX6SX=y
@@ -29,2 +20,0 @@ 
-CONFIG_SOC_IMX7ULP=y
-CONFIG_SOC_VF610=y
@@ -36 +25,0 @@ 
-CONFIG_KEXEC=y
@@ -58,0 +48 @@ 
+# CONFIG_SWAP is not set
@@ -67,0 +58,2 @@ 
+CONFIG_CAN_FLEXCAN=y
+CONFIG_CAN_MCP251X=m
@@ -71,0 +64,2 @@ 
+CONFIG_BT_MRVL=m
+CONFIG_BT_MRVL_SDIO=m
@@ -101 +94,0 @@ 
-CONFIG_MTD_NAND_VF610_NFC=y
@@ -103 +95,0 @@ 
-CONFIG_MTD_SPI_NOR=y
@@ -121 +112,0 @@ 
-CONFIG_PATA_IMX=y
@@ -138 +128,0 @@ 
-CONFIG_CAN_FLEXCAN=y
@@ -200,0 +191 @@ 
+CONFIG_SPI_MEM=y
@@ -204,5 +195 @@ 
-CONFIG_SPI_FSL_DSPI=y
-CONFIG_PINCTRL_IMX8MM=y
-CONFIG_PINCTRL_IMX8MN=y
-CONFIG_PINCTRL_IMX8MP=y
-CONFIG_PINCTRL_IMX8MQ=y
+CONFIG_SPI_SPIDEV=y
@@ -240,0 +228 @@ 
+CONFIG_REGULATOR=y
@@ -252,3 +239,0 @@ 
-CONFIG_RC_CORE=y
-CONFIG_RC_DEVICES=y
-CONFIG_IR_GPIO_CIR=y
@@ -269 +253,0 @@ 
-CONFIG_DRM_MSM=y
@@ -273,0 +258 @@ 
+CONFIG_DRM_SIMPLE_BRIDGE=y
@@ -391,5 +376 @@ 
-CONFIG_CLK_IMX8MM=y
-CONFIG_CLK_IMX8MN=y
-CONFIG_CLK_IMX8MP=y
-CONFIG_CLK_IMX8MQ=y
-CONFIG_SOC_IMX8M=y
+CONFIG_EXTCON_USB_GPIO=y
@@ -410 +390,0 @@ 
-CONFIG_NVMEM_VF610_OCOTP=y
@@ -417 +397 @@ 
-CONFIG_EXT2_FS=y
+CONFIG_EXT2_FS=m
@@ -421 +401 @@ 
-CONFIG_EXT3_FS=y
+CONFIG_EXT3_FS=m
@@ -423,0 +404 @@ 
+CONFIG_EXT4_FS=y
@@ -428 +409 @@ 
-CONFIG_FUSE_FS=y
+CONFIG_FUSE_FS=m
@@ -434,0 +416 @@ 
+CONFIG_NTFS3_FS=m
@@ -436 +418 @@ 
-CONFIG_JFFS2_FS=y
+CONFIG_JFFS2_FS=m
@@ -457 +439,3 @@ 
-CONFIG_CMA_SIZE_MBYTES=64
+CONFIG_CMA_SIZE_MBYTES=256
+CONFIG_CMA_SIZE_PERCENTAGE=50
+CONFIG_CMA_SIZE_SEL_MIN=y
@@ -461,0 +446 @@ 
+CONFIG_DYNAMIC_DEBUG=y