btrfs: fix use-after-free when attempting to join an aborted transaction
When we are trying to join the current transaction and if it's aborted,
we read its 'aborted' field after unlocking fs_info->trans_lock and
without holding any extra reference count on it. This means that a
concurrent task that is aborting the transaction may free the transaction
before we read its 'aborted' field, leading to a use-after-free.
Fix this by reading the 'aborted' field while holding fs_info->trans_lock
since any freeing task must first acquire that lock and set
fs_info->running_transaction to NULL before freeing the transaction.
This was reported by syzbot and Dmitry with the following stack traces
from KASAN:
==================================================================
BUG: KASAN: slab-use-after-free in join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278
Read of size 4 at addr ffff888011839024 by task kworker/u4:9/1128
CPU: 0 UID: 0 PID: 1128 Comm: kworker/u4:9 Not tainted 6.13.0-rc7-syzkaller-00019-gc45323b7560e #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: events_unbound btrfs_async_reclaim_data_space
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x169/0x550 mm/kasan/report.c:489
kasan_report+0x143/0x180 mm/kasan/report.c:602
join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278
start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697
flush_space+0x448/0xcf0 fs/btrfs/space-info.c:803
btrfs_async_reclaim_data_space+0x159/0x510 fs/btrfs/space-info.c:1321
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317
worker_thread+0x870/0xd30 kernel/workqueue.c:3398
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Allocated by task 5315:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329
kmalloc_noprof include/linux/slab.h:901 [inline]
join_transaction+0x144/0xda0 fs/btrfs/transaction.c:308
start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697
btrfs_create_common+0x1b2/0x2e0 fs/btrfs/inode.c:6572
lookup_open fs/namei.c:3649 [inline]
open_last_lookups fs/namei.c:3748 [inline]
path_openat+0x1c03/0x3590 fs/namei.c:3984
do_filp_open+0x27f/0x4e0 fs/namei.c:4014
do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
do_sys_open fs/open.c:1417 [inline]
__do_sys_creat fs/open.c:1495 [inline]
__se_sys_creat fs/open.c:1489 [inline]
__x64_sys_creat+0x123/0x170 fs/open.c:1489
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 5336:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2353 [inline]
slab_free mm/slub.c:4613 [inline]
kfree+0x196/0x430 mm/slub.c:4761
cleanup_transaction fs/btrfs/transaction.c:2063 [inline]
btrfs_commit_transaction+0x2c97/0x3720 fs/btrfs/transaction.c:2598
insert_balance_item+0x1284/0x20b0 fs/btrfs/volumes.c:3757
btrfs_balance+0x992/
---truncated---
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 |
|---|---|---|
Debian DLA |
DLA-4102-1 | linux-6.1 security update |
Debian DLA |
DLA-4178-1 | linux security update |
EUVD |
EUVD-2025-5190 | In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free when attempting to join an aborted transaction When we are trying to join the current transaction and if it's aborted, we read its 'aborted' field after unlocking fs_info->trans_lock and without holding any extra reference count on it. This means that a concurrent task that is aborting the transaction may free the transaction before we read its 'aborted' field, leading to a use-after-free. Fix this by reading the 'aborted' field while holding fs_info->trans_lock since any freeing task must first acquire that lock and set fs_info->running_transaction to NULL before freeing the transaction. This was reported by syzbot and Dmitry with the following stack traces from KASAN: ================================================================== BUG: KASAN: slab-use-after-free in join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278 Read of size 4 at addr ffff888011839024 by task kworker/u4:9/1128 CPU: 0 UID: 0 PID: 1128 Comm: kworker/u4:9 Not tainted 6.13.0-rc7-syzkaller-00019-gc45323b7560e #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events_unbound btrfs_async_reclaim_data_space Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278 start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697 flush_space+0x448/0xcf0 fs/btrfs/space-info.c:803 btrfs_async_reclaim_data_space+0x159/0x510 fs/btrfs/space-info.c:1321 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 5315: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329 kmalloc_noprof include/linux/slab.h:901 [inline] join_transaction+0x144/0xda0 fs/btrfs/transaction.c:308 start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697 btrfs_create_common+0x1b2/0x2e0 fs/btrfs/inode.c:6572 lookup_open fs/namei.c:3649 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3984 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_creat fs/open.c:1495 [inline] __se_sys_creat fs/open.c:1489 [inline] __x64_sys_creat+0x123/0x170 fs/open.c:1489 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5336: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4613 [inline] kfree+0x196/0x430 mm/slub.c:4761 cleanup_transaction fs/btrfs/transaction.c:2063 [inline] btrfs_commit_transaction+0x2c97/0x3720 fs/btrfs/transaction.c:2598 insert_balance_item+0x1284/0x20b0 fs/btrfs/volumes.c:3757 btrfs_balance+0x992/ ---truncated--- |
Ubuntu USN |
USN-7510-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7510-2 | Linux kernel (FIPS) vulnerabilities |
Ubuntu USN |
USN-7510-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7510-4 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-7510-5 | Linux kernel (Azure FIPS) vulnerabilities |
Ubuntu USN |
USN-7510-6 | Linux kernel (AWS FIPS) vulnerabilities |
Ubuntu USN |
USN-7510-7 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7510-8 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-7511-1 | Linux kernel (GCP) vulnerabilities |
Ubuntu USN |
USN-7511-2 | Linux kernel (GCP FIPS) vulnerabilities |
Ubuntu USN |
USN-7511-3 | Linux kernel (GKE) vulnerabilities |
Ubuntu USN |
USN-7512-1 | Linux kernel (GCP) vulnerabilities |
Ubuntu USN |
USN-7516-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7516-2 | Linux kernel (GCP FIPS) vulnerabilities |
Ubuntu USN |
USN-7516-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7516-4 | Linux kernel (Oracle) vulnerabilities |
Ubuntu USN |
USN-7516-5 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-7516-6 | Linux kernel (IBM) vulnerabilities |
Ubuntu USN |
USN-7516-7 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-7516-8 | Linux kernel (FIPS) vulnerabilities |
Ubuntu USN |
USN-7516-9 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-7517-1 | Linux kernel (Xilinx ZynqMP) vulnerabilities |
Ubuntu USN |
USN-7517-2 | Linux kernel (IBM) vulnerabilities |
Ubuntu USN |
USN-7517-3 | Linux kernel (BlueField) vulnerabilities |
Ubuntu USN |
USN-7518-1 | Linux kernel (Azure FIPS) vulnerabilities |
Ubuntu USN |
USN-7521-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7521-2 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-7521-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7539-1 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-7540-1 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-7593-1 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-7602-1 | Linux kernel (Xilinx ZynqMP) vulnerabilities |
Ubuntu USN |
USN-7640-1 | Linux kernel (IoT) vulnerabilities |
Ubuntu USN |
USN-7651-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7651-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7651-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7651-4 | Linux kernel (GCP) vulnerabilities |
Ubuntu USN |
USN-7651-5 | Linux kernel (Raspberry Pi Real-time) vulnerabilities |
Ubuntu USN |
USN-7651-6 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-7652-1 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-7653-1 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-7737-1 | Linux kernel (Azure) vulnerabilities |
Tue, 12 May 2026 13:30:00 +0000
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| References |
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Mon, 03 Nov 2025 20:30:00 +0000
| Type | Values Removed | Values Added |
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| References |
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Mon, 24 Mar 2025 17:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
Thu, 13 Mar 2025 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Tue, 04 Mar 2025 03:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Fri, 28 Feb 2025 02:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
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| Metrics |
threat_severity
|
threat_severity
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Thu, 27 Feb 2025 19:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-416 | |
| Metrics |
cvssV3_1
|
Thu, 27 Feb 2025 02:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free when attempting to join an aborted transaction When we are trying to join the current transaction and if it's aborted, we read its 'aborted' field after unlocking fs_info->trans_lock and without holding any extra reference count on it. This means that a concurrent task that is aborting the transaction may free the transaction before we read its 'aborted' field, leading to a use-after-free. Fix this by reading the 'aborted' field while holding fs_info->trans_lock since any freeing task must first acquire that lock and set fs_info->running_transaction to NULL before freeing the transaction. This was reported by syzbot and Dmitry with the following stack traces from KASAN: ================================================================== BUG: KASAN: slab-use-after-free in join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278 Read of size 4 at addr ffff888011839024 by task kworker/u4:9/1128 CPU: 0 UID: 0 PID: 1128 Comm: kworker/u4:9 Not tainted 6.13.0-rc7-syzkaller-00019-gc45323b7560e #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events_unbound btrfs_async_reclaim_data_space Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278 start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697 flush_space+0x448/0xcf0 fs/btrfs/space-info.c:803 btrfs_async_reclaim_data_space+0x159/0x510 fs/btrfs/space-info.c:1321 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 5315: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329 kmalloc_noprof include/linux/slab.h:901 [inline] join_transaction+0x144/0xda0 fs/btrfs/transaction.c:308 start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697 btrfs_create_common+0x1b2/0x2e0 fs/btrfs/inode.c:6572 lookup_open fs/namei.c:3649 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3984 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_creat fs/open.c:1495 [inline] __se_sys_creat fs/open.c:1489 [inline] __x64_sys_creat+0x123/0x170 fs/open.c:1489 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5336: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4613 [inline] kfree+0x196/0x430 mm/slub.c:4761 cleanup_transaction fs/btrfs/transaction.c:2063 [inline] btrfs_commit_transaction+0x2c97/0x3720 fs/btrfs/transaction.c:2598 insert_balance_item+0x1284/0x20b0 fs/btrfs/volumes.c:3757 btrfs_balance+0x992/ ---truncated--- | |
| Title | btrfs: fix use-after-free when attempting to join an aborted transaction | |
| References |
|
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-12T12:03:36.932Z
Reserved: 2024-12-29T08:45:45.760Z
Link: CVE-2025-21753
Updated: 2025-11-03T19:36:58.333Z
Status : Modified
Published: 2025-02-27T03:15:15.950
Modified: 2026-05-12T13:16:34.510
Link: CVE-2025-21753
OpenCVE Enrichment
No data.
Debian DLA
EUVD
Ubuntu USN