Security assessments indicate that CVE-2021-47510 presents a notable risk, potentially requiring prompt mitigation.
Status: Analyzed
Last updated: 🕔 29 Sep 2025, 17:11 UTC
Originally published on: 🕒 24 May 2024, 15:15 UTC
Time between publication and last update: 493 days
CVSS Release: version 3
nvd@nist.gov
Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVE-2021-47510: In the Linux kernel, the following vulnerability has been resolved: btrfs: fix re-dirty process of tree-log nodes There is a report of a transaction abort of -EAGAIN with the following script. #!/bin/sh for d in sda sdb; do mkfs.btrfs -d single -m single -f /dev/\${d} done mount /dev/sda /mnt/test mount /dev/sdb /mnt/scratch for dir in test scratch; do echo 3 >/proc/sys/vm/drop_caches fio --directory=/mnt/\${dir} --name=fio.\${dir} --rw=read --size=50G --bs=64m \ --numjobs=$(nproc) --time_based --ramp_time=5 --runtime=480 \ --group_reporting |& tee /dev/shm/fio.\${dir} echo 3 >/proc/sys/vm/drop_caches done for d in sda sdb; do umount /dev/\${d} done The stack trace is shown in below. [3310.967991] BTRFS: error (device sda) in btrfs_commit_transaction:2341: errno=-11 unknown (Error while writing out transaction) [3310.968060] BTRFS info (device sda): forced readonly [3310.968064] BTRFS warning (device sda): Skipping commit of aborted transaction. [3310.968065] ------------[ cut here ]------------ [3310.968066] BTRFS: Transaction aborted (error -11) [3310.968074] WARNING: CPU: 14 PID: 1684 at fs/btrfs/transaction.c:1946 btrfs_commit_transaction.cold+0x209/0x2c8 [3310.968131] CPU: 14 PID: 1684 Comm: fio Not tainted 5.14.10-300.fc35.x86_64 #1 [3310.968135] Hardware name: DIAWAY Tartu/Tartu, BIOS V2.01.B10 04/08/2021 [3310.968137] RIP: 0010:btrfs_commit_transaction.cold+0x209/0x2c8 [3310.968144] RSP: 0018:ffffb284ce393e10 EFLAGS: 00010282 [3310.968147] RAX: 0000000000000026 RBX: ffff973f147b0f60 RCX: 0000000000000027 [3310.968149] RDX: ffff974ecf098a08 RSI: 0000000000000001 RDI: ffff974ecf098a00 [3310.968150] RBP: ffff973f147b0f08 R08: 0000000000000000 R09: ffffb284ce393c48 [3310.968151] R10: ffffb284ce393c40 R11: ffffffff84f47468 R12: ffff973f101bfc00 [3310.968153] R13: ffff971f20cf2000 R14: 00000000fffffff5 R15: ffff973f147b0e58 [3310.968154] FS: 00007efe65468740(0000) GS:ffff974ecf080000(0000) knlGS:0000000000000000 [3310.968157] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [3310.968158] CR2: 000055691bcbe260 CR3: 000000105cfa4001 CR4: 0000000000770ee0 [3310.968160] PKRU: 55555554 [3310.968161] Call Trace: [3310.968167] ? dput+0xd4/0x300 [3310.968174] btrfs_sync_file+0x3f1/0x490 [3310.968180] __x64_sys_fsync+0x33/0x60 [3310.968185] do_syscall_64+0x3b/0x90 [3310.968190] entry_SYSCALL_64_after_hwframe+0x44/0xae [3310.968194] RIP: 0033:0x7efe6557329b [3310.968200] RSP: 002b:00007ffe0236ebc0 EFLAGS: 00000293 ORIG_RAX: 000000000000004a [3310.968203] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007efe6557329b [3310.968204] RDX: 0000000000000000 RSI: 00007efe58d77010 RDI: 0000000000000006 [3310.968205] RBP: 0000000004000000 R08: 0000000000000000 R09: 00007efe58d77010 [3310.968207] R10: 0000000016cacc0c R11: 0000000000000293 R12: 00007efe5ce95980 [3310.968208] R13: 0000000000000000 R14: 00007efe6447c790 R15: 0000000c80000000 [3310.968212] ---[ end trace 1a346f4d3c0d96ba ]--- [3310.968214] BTRFS: error (device sda) in cleanup_transaction:1946: errno=-11 unknown The abort occurs because of a write hole while writing out freeing tree nodes of a tree-log tree. For zoned btrfs, we re-dirty a freed tree node to ensure btrfs can write the region and does not leave a hole on write on a zoned device. The current code fails to re-dirty a node when the tree-log tree's depth is greater or equal to 2. That leads to a transaction abort with -EAGAIN. Fix the issue by properly re-dirtying a node on walking up the tree.
The exploitability of CVE-2021-47510 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
CVE-2021-47510 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2021-47510, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2021-47510, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
The EPSS score estimates the probability that this vulnerability will be exploited in the near future.
EPSS Score: 0.043% (probability of exploit)
EPSS Percentile: 12.0%
(lower percentile = lower relative risk)
This vulnerability is less risky than approximately 88.0% of others.
NVD-CWE-noinfo
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