ubifs: Fix deadlock in concurrent rename whiteout and inode writeback
Following hung tasks:
[ 77.028764] task:kworker/u8:4 state:D stack: 0 pid: 132
[ 77.028820] Call Trace:
[ 77.029027] schedule+0x8c/0x1b0
[ 77.029067] mutex_lock+0x50/0x60
[ 77.029074] ubifs_write_inode+0x68/0x1f0 [ubifs]
[ 77.029117] __writeback_single_inode+0x43c/0x570
[ 77.029128] writeback_sb_inodes+0x259/0x740
[ 77.029148] wb_writeback+0x107/0x4d0
[ 77.029163] wb_workfn+0x162/0x7b0
[ 92.390442] task:aa state:D stack: 0 pid: 1506
[ 92.390448] Call Trace:
[ 92.390458] schedule+0x8c/0x1b0
[ 92.390461] wb_wait_for_completion+0x82/0xd0
[ 92.390469] __writeback_inodes_sb_nr+0xb2/0x110
[ 92.390472] writeback_inodes_sb_nr+0x14/0x20
[ 92.390476] ubifs_budget_space+0x705/0xdd0 [ubifs]
[ 92.390503] do_rename.cold+0x7f/0x187 [ubifs]
[ 92.390549] ubifs_rename+0x8b/0x180 [ubifs]
[ 92.390571] vfs_rename+0xdb2/0x1170
[ 92.390580] do_renameat2+0x554/0x770
, are caused by concurrent rename whiteout and inode writeback processes:
rename_whiteout(Thread 1) wb_workfn(Thread2)
ubifs_rename
do_rename
lock_4_inodes (Hold ui_mutex)
ubifs_budget_space
make_free_space
shrink_liability
__writeback_inodes_sb_nr
bdi_split_work_to_wbs (Queue new wb work)
wb_do_writeback(wb work)
__writeback_single_inode
ubifs_write_inode
LOCK(ui_mutex)
↑
wb_wait_for_completion (Wait wb work) <-- deadlock!
Reproducer (Detail program in [Link]):
1. SYS_renameat2("/mp/dir/file", "/mp/dir/whiteout", RENAME_WHITEOUT)
2. Consume out of space before kernel(mdelay) doing budget for whiteout
Fix it by doing whiteout space budget before locking ubifs inodes.
BTW, it also fixes wrong goto tag 'out_release' in whiteout budget
error handling path(It should at least recover dir i_size and unlock
4 ubifs inodes).
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2021-34667 | In the Linux kernel, the following vulnerability has been resolved: ubifs: Fix deadlock in concurrent rename whiteout and inode writeback Following hung tasks: [ 77.028764] task:kworker/u8:4 state:D stack: 0 pid: 132 [ 77.028820] Call Trace: [ 77.029027] schedule+0x8c/0x1b0 [ 77.029067] mutex_lock+0x50/0x60 [ 77.029074] ubifs_write_inode+0x68/0x1f0 [ubifs] [ 77.029117] __writeback_single_inode+0x43c/0x570 [ 77.029128] writeback_sb_inodes+0x259/0x740 [ 77.029148] wb_writeback+0x107/0x4d0 [ 77.029163] wb_workfn+0x162/0x7b0 [ 92.390442] task:aa state:D stack: 0 pid: 1506 [ 92.390448] Call Trace: [ 92.390458] schedule+0x8c/0x1b0 [ 92.390461] wb_wait_for_completion+0x82/0xd0 [ 92.390469] __writeback_inodes_sb_nr+0xb2/0x110 [ 92.390472] writeback_inodes_sb_nr+0x14/0x20 [ 92.390476] ubifs_budget_space+0x705/0xdd0 [ubifs] [ 92.390503] do_rename.cold+0x7f/0x187 [ubifs] [ 92.390549] ubifs_rename+0x8b/0x180 [ubifs] [ 92.390571] vfs_rename+0xdb2/0x1170 [ 92.390580] do_renameat2+0x554/0x770 , are caused by concurrent rename whiteout and inode writeback processes: rename_whiteout(Thread 1) wb_workfn(Thread2) ubifs_rename do_rename lock_4_inodes (Hold ui_mutex) ubifs_budget_space make_free_space shrink_liability __writeback_inodes_sb_nr bdi_split_work_to_wbs (Queue new wb work) wb_do_writeback(wb work) __writeback_single_inode ubifs_write_inode LOCK(ui_mutex) ↑ wb_wait_for_completion (Wait wb work) <-- deadlock! Reproducer (Detail program in [Link]): 1. SYS_renameat2("/mp/dir/file", "/mp/dir/whiteout", RENAME_WHITEOUT) 2. Consume out of space before kernel(mdelay) doing budget for whiteout Fix it by doing whiteout space budget before locking ubifs inodes. BTW, it also fixes wrong goto tag 'out_release' in whiteout budget error handling path(It should at least recover dir i_size and unlock 4 ubifs inodes). |
Tue, 18 Mar 2025 20:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | CWE-667 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
Fri, 28 Feb 2025 14:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Wed, 26 Feb 2025 02:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: ubifs: Fix deadlock in concurrent rename whiteout and inode writeback Following hung tasks: [ 77.028764] task:kworker/u8:4 state:D stack: 0 pid: 132 [ 77.028820] Call Trace: [ 77.029027] schedule+0x8c/0x1b0 [ 77.029067] mutex_lock+0x50/0x60 [ 77.029074] ubifs_write_inode+0x68/0x1f0 [ubifs] [ 77.029117] __writeback_single_inode+0x43c/0x570 [ 77.029128] writeback_sb_inodes+0x259/0x740 [ 77.029148] wb_writeback+0x107/0x4d0 [ 77.029163] wb_workfn+0x162/0x7b0 [ 92.390442] task:aa state:D stack: 0 pid: 1506 [ 92.390448] Call Trace: [ 92.390458] schedule+0x8c/0x1b0 [ 92.390461] wb_wait_for_completion+0x82/0xd0 [ 92.390469] __writeback_inodes_sb_nr+0xb2/0x110 [ 92.390472] writeback_inodes_sb_nr+0x14/0x20 [ 92.390476] ubifs_budget_space+0x705/0xdd0 [ubifs] [ 92.390503] do_rename.cold+0x7f/0x187 [ubifs] [ 92.390549] ubifs_rename+0x8b/0x180 [ubifs] [ 92.390571] vfs_rename+0xdb2/0x1170 [ 92.390580] do_renameat2+0x554/0x770 , are caused by concurrent rename whiteout and inode writeback processes: rename_whiteout(Thread 1) wb_workfn(Thread2) ubifs_rename do_rename lock_4_inodes (Hold ui_mutex) ubifs_budget_space make_free_space shrink_liability __writeback_inodes_sb_nr bdi_split_work_to_wbs (Queue new wb work) wb_do_writeback(wb work) __writeback_single_inode ubifs_write_inode LOCK(ui_mutex) ↑ wb_wait_for_completion (Wait wb work) <-- deadlock! Reproducer (Detail program in [Link]): 1. SYS_renameat2("/mp/dir/file", "/mp/dir/whiteout", RENAME_WHITEOUT) 2. Consume out of space before kernel(mdelay) doing budget for whiteout Fix it by doing whiteout space budget before locking ubifs inodes. BTW, it also fixes wrong goto tag 'out_release' in whiteout budget error handling path(It should at least recover dir i_size and unlock 4 ubifs inodes). | |
| Title | ubifs: Fix deadlock in concurrent rename whiteout and inode writeback | |
| References |
|
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T13:58:14.868Z
Reserved: 2025-02-26T01:48:21.519Z
Link: CVE-2021-47637
No data.
Status : Modified
Published: 2025-02-26T06:37:05.477
Modified: 2025-10-01T20:15:40.573
Link: CVE-2021-47637
OpenCVE Enrichment
No data.
EUVD