CVE-2022-48734

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix deadlock between quota disable and qgroup rescan worker Quota disable ioctl starts a transaction before waiting for the qgroup rescan worker completes. However, this wait can be infinite and results in deadlock because of circular dependency among the quota disable ioctl, the qgroup rescan worker and the other task with transaction such as block group relocation task. The deadlock happens with the steps following: 1) Task A calls ioctl to disable quota. It starts a transaction and waits for qgroup rescan worker completes. 2) Task B such as block group relocation task starts a transaction and joins to the transaction that task A started. Then task B commits to the transaction. In this commit, task B waits for a commit by task A. 3) Task C as the qgroup rescan worker starts its job and starts a transaction. In this transaction start, task C waits for completion of the transaction that task A started and task B committed. This deadlock was found with fstests test case btrfs/115 and a zoned null_blk device. The test case enables and disables quota, and the block group reclaim was triggered during the quota disable by chance. The deadlock was also observed by running quota enable and disable in parallel with 'btrfs balance' command on regular null_blk devices. An example report of the deadlock: [372.469894] INFO: task kworker/u16:6:103 blocked for more than 122 seconds. [372.479944] Not tainted 5.16.0-rc8 #7 [372.485067] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [372.493898] task:kworker/u16:6 state:D stack: 0 pid: 103 ppid: 2 flags:0x00004000 [372.503285] Workqueue: btrfs-qgroup-rescan btrfs_work_helper [btrfs] [372.510782] Call Trace: [372.514092] <TASK> [372.521684] __schedule+0xb56/0x4850 [372.530104] ? io_schedule_timeout+0x190/0x190 [372.538842] ? lockdep_hardirqs_on+0x7e/0x100 [372.547092] ? _raw_spin_unlock_irqrestore+0x3e/0x60 [372.555591] schedule+0xe0/0x270 [372.561894] btrfs_commit_transaction+0x18bb/0x2610 [btrfs] [372.570506] ? btrfs_apply_pending_changes+0x50/0x50 [btrfs] [372.578875] ? free_unref_page+0x3f2/0x650 [372.585484] ? finish_wait+0x270/0x270 [372.591594] ? release_extent_buffer+0x224/0x420 [btrfs] [372.599264] btrfs_qgroup_rescan_worker+0xc13/0x10c0 [btrfs] [372.607157] ? lock_release+0x3a9/0x6d0 [372.613054] ? btrfs_qgroup_account_extent+0xda0/0xda0 [btrfs] [372.620960] ? do_raw_spin_lock+0x11e/0x250 [372.627137] ? rwlock_bug.part.0+0x90/0x90 [372.633215] ? lock_is_held_type+0xe4/0x140 [372.639404] btrfs_work_helper+0x1ae/0xa90 [btrfs] [372.646268] process_one_work+0x7e9/0x1320 [372.652321] ? lock_release+0x6d0/0x6d0 [372.658081] ? pwq_dec_nr_in_flight+0x230/0x230 [372.664513] ? rwlock_bug.part.0+0x90/0x90 [372.670529] worker_thread+0x59e/0xf90 [372.676172] ? process_one_work+0x1320/0x1320 [372.682440] kthread+0x3b9/0x490 [372.687550] ? _raw_spin_unlock_irq+0x24/0x50 [372.693811] ? set_kthread_struct+0x100/0x100 [372.700052] ret_from_fork+0x22/0x30 [372.705517] </TASK> [372.709747] INFO: task btrfs-transacti:2347 blocked for more than 123 seconds. [372.729827] Not tainted 5.16.0-rc8 #7 [372.745907] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [372.767106] task:btrfs-transacti state:D stack: 0 pid: 2347 ppid: 2 flags:0x00004000 [372.787776] Call Trace: [372.801652] <TASK> [372.812961] __schedule+0xb56/0x4850 [372.830011] ? io_schedule_timeout+0x190/0x190 [372.852547] ? lockdep_hardirqs_on+0x7e/0x100 [372.871761] ? _raw_spin_unlock_irqrestore+0x3e/0x60 [372.886792] schedule+0xe0/0x270 [372.901685] wait_current_trans+0x22c/0x310 [btrfs] [372.919743] ? btrfs_put_transaction+0x3d0/0x3d0 [btrfs] [372.938923] ? finish_wait+0x270/0x270 [372.959085] ? join_transaction+0xc7 ---truncated---
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

History

19 Aug 2024, 17:22

Type Values Removed Values Added
First Time Linux
Linux linux Kernel
Summary
  • (es) En el kernel de Linux, se resolvió la siguiente vulnerabilidad: btrfs: soluciona el punto muerto entre la desactivación de cuota y el trabajador de rescaneo de qgroup. La desactivación de cuota ioctl inicia una transacción antes de esperar a que se complete el trabajador de rescaneo de qgroup. Sin embargo, esta espera puede ser infinita y provocar un punto muerto debido a la dependencia circular entre el ioctl de desactivación de cuota, el trabajador de rescaneo de qgroup y la otra tarea con transacciones como la tarea de reubicación del grupo de bloques. El punto muerto ocurre con los siguientes pasos: 1) La tarea A llama a ioctl para deshabilitar la cuota. Inicia una transacción y espera a que se complete el trabajo de rescaneo de qgroup. 2) La tarea B, como la tarea de reubicación del grupo de bloques, inicia una transacción y se une a la transacción que inició la tarea A. Luego la tarea B se compromete con la transacción. En esta confirmación, la tarea B espera una confirmación de la tarea A. 3) La tarea C, como trabajador de rescaneo de qgroup, inicia su trabajo e inicia una transacción. En el inicio de esta transacción, la tarea C espera a que se complete la transacción que inició la tarea A y confirmó la tarea B. Este punto muerto se encontró con el caso de prueba btrfs/115 de fstests y un dispositivo null_blk zonificado. El caso de prueba habilita y deshabilita la cuota, y la recuperación del grupo de bloques se activó durante la deshabilitación de la cuota por casualidad. El punto muerto también se observó al ejecutar la habilitación y deshabilitación de cuotas en paralelo con el comando 'btrfs balance' en dispositivos null_blk normales. Un informe de ejemplo del punto muerto: [372.469894] INFORMACIÓN: tarea kworker/u16:6:103 bloqueada durante más de 122 segundos. [372.479944] No contaminado 5.16.0-rc8 #7 [372.485067] "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" desactiva este mensaje. [372.493898] tarea:kworker/u16:6 estado:D pila: 0 pid: 103 ppid: 2 banderas:0x00004000 [372.503285] Cola de trabajo: btrfs-qgroup-rescan btrfs_work_helper [btrfs] [372.510782] Seguimiento de llamadas: [372.521684] __programación+0xb56/0x4850 [372.530104] ? io_schedule_timeout+0x190/0x190 [372.538842] ? lockdep_hardirqs_on+0x7e/0x100 [372.547092] ? _raw_spin_unlock_irqrestore+0x3e/0x60 [372.555591] horario+0xe0/0x270 [372.561894] btrfs_commit_transaction+0x18bb/0x2610 [btrfs] [372.570506] ? btrfs_apply_pending_changes+0x50/0x50 [btrfs] [372.578875] ? free_unref_page+0x3f2/0x650 [372.585484] ? terminar_esperar+0x270/0x270 [372.591594] ? release_extent_buffer+0x224/0x420 [btrfs] [372.599264] btrfs_qgroup_rescan_worker+0xc13/0x10c0 [btrfs] [372.607157] ? lock_release+0x3a9/0x6d0 [372.613054]? btrfs_qgroup_account_extent+0xda0/0xda0 [btrfs] [372.620960]? do_raw_spin_lock+0x11e/0x250 [372.627137]? rwlock_bug.part.0+0x90/0x90 [372.633215] ? lock_is_held_type+0xe4/0x140 [372.639404] btrfs_work_helper+0x1ae/0xa90 [btrfs] [372.646268] Process_one_work+0x7e9/0x1320 [372.652321] ? lock_release+0x6d0/0x6d0 [372.658081]? pwq_dec_nr_in_flight+0x230/0x230 [372.664513] ? rwlock_bug.part.0+0x90/0x90 [372.670529] trabajador_thread+0x59e/0xf90 [372.676172] ? proceso_one_work+0x1320/0x1320 [372.682440] kthread+0x3b9/0x490 [372.687550] ? _raw_spin_unlock_irq+0x24/0x50 [372.693811] ? set_kthread_struct+0x100/0x100 [372.700052] ret_from_fork+0x22/0x30 [372.705517] [372.709747] INFORMACIÓN: tarea btrfs-transacti:2347 bloqueada durante más de 123 segundos. [372.729827] No contaminado 5.16.0-rc8 #7 [372.745907] "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" desactiva este mensaje. [372.767106] tarea: btrfs-transacti estado: D pila: 0 pid: 2347 ppid: 2 banderas: 0x00004000 [372.787776] Seguimiento de llamadas: [372.801652] [372.812961] __schedule+0xb56/0x4850 [372.83 0011] ? io_schedule_timeout+0x190/0x190 [372.852547] ? lockdep_hardirqs_on+0x7e/0x100 [372.871761]? _raw_spin_unlock_irqrestore+0x3e/0x60 [372.886792] horario+0xe0/0x270 [372.901685] ---truncado---
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
CWE CWE-667
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.5
References () https://git.kernel.org/stable/c/26b3901d20bf9da2c6a00cb1fb48932166f80a45 - () https://git.kernel.org/stable/c/26b3901d20bf9da2c6a00cb1fb48932166f80a45 - Patch
References () https://git.kernel.org/stable/c/31198e58c09e21d4f65c49d2361f76b87aca4c3f - () https://git.kernel.org/stable/c/31198e58c09e21d4f65c49d2361f76b87aca4c3f - Patch
References () https://git.kernel.org/stable/c/32747e01436aac8ef93fe85b5b523b4f3b52f040 - () https://git.kernel.org/stable/c/32747e01436aac8ef93fe85b5b523b4f3b52f040 - Patch
References () https://git.kernel.org/stable/c/89d4cca583fc9594ee7d1a0bc986886d6fb587e6 - () https://git.kernel.org/stable/c/89d4cca583fc9594ee7d1a0bc986886d6fb587e6 - Patch
References () https://git.kernel.org/stable/c/e804861bd4e69cc5fe1053eedcb024982dde8e48 - () https://git.kernel.org/stable/c/e804861bd4e69cc5fe1053eedcb024982dde8e48 - Patch

20 Jun 2024, 12:15

Type Values Removed Values Added
New CVE

Information

Published : 2024-06-20 12:15

Updated : 2024-08-19 17:22


NVD link : CVE-2022-48734

Mitre link : CVE-2022-48734

CVE.ORG link : CVE-2022-48734


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-667

Improper Locking