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一、漏洞信息
漏洞编号：CVE-2024-26792
漏洞归属组件：kernel
漏洞归属的版本：4.19.140,4.19.194,4.19.90,5.10.0,6.1.0,6.1.14,6.1.19,6.1.5,6.1.6,6.1.8,6.4.0
CVSS V2.0分值：
BaseScore：0.0 Low
Vector：CVSS：2.0/
漏洞简述：
In the Linux kernel, the following vulnerability has been resolved:btrfs: fix double free of anonymous device after snapshot creation failureWhen creating a snapshot we may do a double free of an anonymous devicein case there s an error committing the transaction. The second free mayresult in freeing an anonymous device number that was allocated by someother subsystem in the kernel or another btrfs filesystem.The steps that lead to this:1) At ioctl.c:create_snapshot() we allocate an anonymous device number and assign it to pending_snapshot->anon_dev;2) Then we call btrfs_commit_transaction() and end up at transaction.c:create_pending_snapshot();3) There we call btrfs_get_new_fs_root() and pass it the anonymous device number stored in pending_snapshot->anon_dev;4) btrfs_get_new_fs_root() frees that anonymous device number because btrfs_lookup_fs_root() returned a root - someone else did a lookup of the new root already, which could some task doing backref walking;5) After that some error happens in the transaction commit path, and at ioctl.c:create_snapshot() we jump to the fail label, and after that we free again the same anonymous device number, which in the meanwhile may have been reallocated somewhere else, because pending_snapshot->anon_dev still has the same value as in step 1.Recently syzbot ran into this and reported the following trace: ------------[ cut here ]------------ ida_free called for id=51 which is not allocated. WARNING: CPU: 1 PID: 31038 at lib/idr.c:525 ida_free+0x370/0x420 lib/idr.c:525 Modules linked in: CPU: 1 PID: 31038 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00410-gc02197fc9076 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:ida_free+0x370/0x420 lib/idr.c:525 Code: 10 42 80 3c 28 (...) RSP: 0018:ffffc90015a67300 EFLAGS: 00010246 RAX: be5130472f5dd000 RBX: 0000000000000033 RCX: 0000000000040000 RDX: ffffc90009a7a000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc90015a673f0 R08: ffffffff81577992 R09: 1ffff92002b4cdb4 R10: dffffc0000000000 R11: fffff52002b4cdb5 R12: 0000000000000246 R13: dffffc0000000000 R14: ffffffff8e256b80 R15: 0000000000000246 FS: 00007fca3f4b46c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f167a17b978 CR3: 000000001ed26000 CR4: 0000000000350ef0 Call Trace: btrfs_get_root_ref+0xa48/0xaf0 fs/btrfs/disk-io.c:1346 create_pending_snapshot+0xff2/0x2bc0 fs/btrfs/transaction.c:1837 create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1931 btrfs_commit_transaction+0xf1c/0x3740 fs/btrfs/transaction.c:2404 create_snapshot+0x507/0x880 fs/btrfs/ioctl.c:848 btrfs_mksubvol+0x5d0/0x750 fs/btrfs/ioctl.c:998 btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1044 __btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1306 btrfs_ioctl_snap_create_v2+0x1ca/0x400 fs/btrfs/ioctl.c:1393 btrfs_ioctl+0xa74/0xd40 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfe/0x170 fs/ioctl.c:857 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7fca3e67dda9 Code: 28 00 00 00 (...) RSP: 002b:00007fca3f4b40c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fca3e7abf80 RCX: 00007fca3e67dda9 RDX: 00000000200005c0 RSI: 0000000050009417 RDI: 0000000000000003 RBP: 00007fca3e6ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fca3e7abf80 R15: 00007fff6bf95658 Where we get an explicit message where we attempt to free an anonymousdevice number that is not currently allocated. It happens in a differentcode path from the example below, at btrfs_get_root_ref(), so this changemay not fix the case triggered by sy---truncated---
漏洞公开时间：2024-04-04 17:15:08
漏洞创建时间：2024-04-04 18:03:07
漏洞详情参考链接：
https://nvd.nist.gov/vuln/detail/CVE-2024-26792
漏洞分析指导链接：
https://gitee.com/openeuler/cve-manager/blob/master/cve-vulner-manager/doc/md/manual.md
漏洞数据来源:
openBrain开源漏洞感知系统
漏洞补丁信息：
| 影响的包 | 修复版本 | 修复补丁 | 问题引入补丁 | 来源 |
|---|---|---|---|---|
| linux | https://git.kernel.org/linus/e2b54eaf28df0c978626c9736b94f003b523b451 | https://git.kernel.org/linus/e03ee2fe873eb68c1f9ba5112fee70303ebf9dfb | ubuntu |
二、漏洞分析结构反馈
影响性分析说明：
btrfs: fix double free of anonymous device after snapshot creation failureWhen creating a snapshot we may do a double free of an anonymous devicein case there_x27;s an error committing the transaction. The second free mayresult in freeing an anonymous device number that was allocated by someother subsystem in the kernel or another btrfs filesystem.The steps that lead to this:1) At ioctl.c:create_snapshot() we allocate an anonymous device number and assign it to pending_snapshot->anon_dev;2) Then we call btrfs_commit_transaction() and end up at transaction.c:create_pending_snapshot();3) There we call btrfs_get_new_fs_root() and pass it the anonymous device number stored in pending_snapshot->anon_dev;4) btrfs_get_new_fs_root() frees that anonymous device number because btrfs_lookup_fs_root() returned a root - someone else did a lookup of the new root already, which could some task doing backref walking;5) After that some error happens in the transaction commit path, and at ioctl.c:create_snapshot() we jump to the _x27;fail_x27; label, and after that we free again the same anonymous device number, which in the meanwhile may have been reallocated somewhere else, because pending_snapshot->anon_dev still has the same value as in step 1.Recently syzbot ran into this and reported the following trace: ------------[ cut here ]------------ ida_free called for id=51 which is not allocated. WARNING: CPU: 1 PID: 31038 at lib/idr.c:525 ida_free+0x370/0x420 lib/idr.c:525 Modules linked in: CPU: 1 PID: 31038 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00410-gc02197fc9076 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:ida_free+0x370/0x420 lib/idr.c:525 Code: 10 42 80 3c 28 (...) RSP: 0018:ffffc90015a67300 EFLAGS: 00010246 RAX: be5130472f5dd000 RBX: 0000000000000033 RCX: 0000000000040000 RDX: ffffc90009a7a000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc90015a673f0 R08: ffffffff81577992 R09: 1ffff92002b4cdb4 R10: dffffc0000000000 R11: fffff52002b4cdb5 R12: 0000000000000246 R13: dffffc0000000000 R14: ffffffff8e256b80 R15: 0000000000000246 FS: 00007fca3f4b46c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f167a17b978 CR3: 000000001ed26000 CR4: 0000000000350ef0 Call Trace: <TASK> btrfs_get_root_ref+0xa48/0xaf0 fs/btrfs/disk-io.c:1346 create_pending_snapshot+0xff2/0x2bc0 fs/btrfs/transaction.c:1837 create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1931 btrfs_commit_transaction+0xf1c/0x3740 fs/btrfs/transaction.c:2404 create_snapshot+0x507/0x880 fs/btrfs/ioctl.c:848 btrfs_mksubvol+0x5d0/0x750 fs/btrfs/ioctl.c:998 btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1044 __btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1306 btrfs_ioctl_snap_create_v2+0x1ca/0x400 fs/btrfs/ioctl.c:1393 btrfs_ioctl+0xa74/0xd40 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfe/0x170 fs/ioctl.c:857 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7fca3e67dda9 Code: 28 00 00 00 (...) RSP: 002b:00007fca3f4b40c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fca3e7abf80 RCX: 00007fca3e67dda9 RDX: 00000000200005c0 RSI: 0000000050009417 RDI: 0000000000000003 RBP: 00007fca3e6ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fca3e7abf80 R15: 00007fff6bf95658 </TASK>Where we get an explicit message where we attempt to free an anonymousdevice number that is not currently allocated. It happens in a differentcode path from the example below, at btrfs_get_root_ref(), so this changemay not fix the case triggered by sy---truncated---
openEuler评分：
5.5
Vector：CVSS：3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
受影响版本排查(受影响/不受影响)：
1.openEuler-22.03-LTS(5.10.0):受影响
2.openEuler-22.03-LTS-SP1(5.10.0):受影响
3.openEuler-22.03-LTS-SP2(5.10.0):受影响
4.openEuler-22.03-LTS-SP3(5.10.0):受影响
5.openEuler-20.03-LTS-SP1(4.19.90):不受影响
6.openEuler-20.03-LTS-SP4(4.19.90):不受影响
7.openEuler-22.03-LTS-SP4:不受影响
8.master(6.1.0):不受影响
9.openEuler-22.03-LTS-Next(5.10.0):不受影响
10.openEuler-24.03-LTS:不受影响
11.openEuler-24.03-LTS-Next:不受影响
修复是否涉及abi变化(是/否)：
1.openEuler-20.03-LTS-SP1(4.19.90):否
2.openEuler-20.03-LTS-SP4(4.19.90):否
3.openEuler-22.03-LTS(5.10.0):否
4.openEuler-22.03-LTS-SP1(5.10.0):否
5.openEuler-22.03-LTS-SP2(5.10.0):否
6.openEuler-22.03-LTS-SP3(5.10.0):否
7.master(6.1.0):否
8.openEuler-22.03-LTS-Next(5.10.0):否
9.openEuler-24.03-LTS:否
10.openEuler-24.03-LTS-Next:否
11.openEuler-22.03-LTS-SP4:否
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issue处理注意事项:
1. 当前issue受影响的分支提交pr时, 须在pr描述中填写当前issue编号进行关联, 否则无法关闭当前issue;
2. 模板内容需要填写完整, 无论是受影响或者不受影响都需要填写完整内容,未引入的分支不需要填写, 否则无法关闭当前issue;
3. 以下为模板中需要填写完整的内容, 请复制到评论区回复, 注: 内容的标题名称(影响性分析说明, openEuler评分, 受影响版本排查(受影响/不受影响), 修复是否涉及abi变化(是/否))不能省略,省略后cve-manager将无法正常解析填写内容.
影响性分析说明:
openEuler评分: (评分和向量)
受影响版本排查(受影响/不受影响):
1.master(6.1.0):
2.openEuler-20.03-LTS-SP1(4.19.90):
3.openEuler-20.03-LTS-SP4:
4.openEuler-22.03-LTS(5.10.0):
5.openEuler-22.03-LTS-Next(5.10.0):
6.openEuler-22.03-LTS-SP1(5.10.0):
7.openEuler-22.03-LTS-SP2(5.10.0):
8.openEuler-22.03-LTS-SP3:
9.openEuler-24.03-LTS:
10.openEuler-24.03-LTS-Next:
修复是否涉及abi变化(是/否)：
1.master(6.1.0):
2.openEuler-20.03-LTS-SP1(4.19.90):
3.openEuler-20.03-LTS-SP4:
4.openEuler-22.03-LTS(5.10.0):
5.openEuler-22.03-LTS-Next(5.10.0):
6.openEuler-22.03-LTS-SP1(5.10.0):
7.openEuler-22.03-LTS-SP2(5.10.0):
8.openEuler-22.03-LTS-SP3:
9.openEuler-24.03-LTS:
10.openEuler-24.03-LTS-Next:
issue处理具体操作请参考:
https://gitee.com/openeuler/cve-manager/blob/master/cve-vulner-manager/doc/md/manual.md
pr关联issue具体操作请参考:
https://gitee.com/help/articles/4142
| 参考网址 | 关联pr | 状态 | 补丁链接 |
|---|---|---|---|
| https://nvd.nist.gov/vuln/detail/CVE-2024-26792 | None | None |
https://git.kernel.org/stable/c/eb3441093aad251418921246fc3b224fd1575701 https://git.kernel.org/stable/c/c8ab7521665bd0f8bc4a900244d1d5a7095cc3b9 https://git.kernel.org/stable/c/c34adc20b91a8e55e048b18d63f4f4ae003ecf8f |
| https://ubuntu.com/security/CVE-2024-26792 | None | None | https://discourse.ubuntu.com/c/ubuntu-pro |
| https://www.opencve.io/cve/CVE-2024-26792 | None | None |
https://git.kernel.org/stable/c/eb3441093aad251418921246fc3b224fd1575701 https://git.kernel.org/stable/c/c8ab7521665bd0f8bc4a900244d1d5a7095cc3b9 https://git.kernel.org/stable/c/c34adc20b91a8e55e048b18d63f4f4ae003ecf8f |
| https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2024-26792 | |||
| https://security-tracker.debian.org/tracker/CVE-2024-26792 |
说明：补丁链接仅供初步排查参考，实际可用性请人工再次确认，补丁下载验证可使用CVE补丁工具。
若补丁不准确，烦请在此issue下评论 '/report-patch 参考网址 补丁链接1,补丁链接2' 反馈正确信息，便于我们不断优化工具，不胜感激。
如 /report-patch https://security-tracker.debian.org/tracker/CVE-2021-3997 https://github.com/systemd/systemd/commit/5b1cf7a9be37e20133c0208005274ce4a5b5c6a1
CVE-2024-26792
影响性分析说明：
btrfs: fix double free of anonymous device after snapshot creation failure
When creating a snapshot we may do a double free of an anonymous device
in case there_x27;s an error committing the transaction. The second free may
result in freeing an anonymous device number that was allocated by some
other subsystem in the kernel or another btrfs filesystem.
The steps that lead to this:
At ioctl.c:create_snapshot() we allocate an anonymous device number
and assign it to pending_snapshot->anon_dev;
Then we call btrfs_commit_transaction() and end up at
transaction.c:create_pending_snapshot();
There we call btrfs_get_new_fs_root() and pass it the anonymous device
number stored in pending_snapshot->anon_dev;
btrfs_get_new_fs_root() frees that anonymous device number because
btrfs_lookup_fs_root() returned a root - someone else did a lookup
of the new root already, which could some task doing backref walking;
After that some error happens in the transaction commit path, and at
ioctl.c:create_snapshot() we jump to the _x27;fail_x27; label, and after
that we free again the same anonymous device number, which in the
meanwhile may have been reallocated somewhere else, because
pending_snapshot->anon_dev still has the same value as in step 1.
Recently syzbot ran into this and reported the following trace:
------------[ cut here ]------------
ida_free called for id=51 which is not allocated.
WARNING: CPU: 1 PID: 31038 at lib/idr.c:525 ida_free+0x370/0x420 lib/idr.c:525
Modules linked in:
CPU: 1 PID: 31038 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00410-gc02197fc9076 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:ida_free+0x370/0x420 lib/idr.c:525
Code: 10 42 80 3c 28 (...)
RSP: 0018:ffffc90015a67300 EFLAGS: 00010246
RAX: be5130472f5dd000 RBX: 0000000000000033 RCX: 0000000000040000
RDX: ffffc90009a7a000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc90015a673f0 R08: ffffffff81577992 R09: 1ffff92002b4cdb4
R10: dffffc0000000000 R11: fffff52002b4cdb5 R12: 0000000000000246
R13: dffffc0000000000 R14: ffffffff8e256b80 R15: 0000000000000246
FS: 00007fca3f4b46c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f167a17b978 CR3: 000000001ed26000 CR4: 0000000000350ef0
Call Trace:
<TASK>
btrfs_get_root_ref+0xa48/0xaf0 fs/btrfs/disk-io.c:1346
create_pending_snapshot+0xff2/0x2bc0 fs/btrfs/transaction.c:1837
create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1931
btrfs_commit_transaction+0xf1c/0x3740 fs/btrfs/transaction.c:2404
create_snapshot+0x507/0x880 fs/btrfs/ioctl.c:848
btrfs_mksubvol+0x5d0/0x750 fs/btrfs/ioctl.c:998
btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1044
__btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1306
btrfs_ioctl_snap_create_v2+0x1ca/0x400 fs/btrfs/ioctl.c:1393
btrfs_ioctl+0xa74/0xd40
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfe/0x170 fs/ioctl.c:857
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7fca3e67dda9
Code: 28 00 00 00 (...)
RSP: 002b:00007fca3f4b40c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fca3e7abf80 RCX: 00007fca3e67dda9
RDX: 00000000200005c0 RSI: 0000000050009417 RDI: 0000000000000003
RBP: 00007fca3e6ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fca3e7abf80 R15: 00007fff6bf95658
</TASK>
Where we get an explicit message where we attempt to free an anonymous
device number that is not currently allocated. It happens in a different
code path from the example below, at btrfs_get_root_ref(), so this change
may not fix the case triggered by sy
---truncated---
openEuler评分:(评分和向量)
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.openEuler-20.03-LTS-SP1:不受影响
2.openEuler-20.03-LTS-SP4:不受影响
3.openEuler-22.03-LTS:受影响
4.openEuler-22.03-LTS-SP1:受影响
5.openEuler-22.03-LTS-SP2:受影响
6.openEuler-22.03-LTS-SP3:受影响
7.master(6.1.0):不受影响
8.openEuler-22.03-LTS-Next:不受影响
9.openEuler-24.03-LTS:不受影响
10.openEuler-24.03-LTS-Next:不受影响
修复是否涉及abi变化(是/否)：
1.openEuler-20.03-LTS-SP1(4.19.90):否
2.openEuler-20.03-LTS-SP4:否
3.openEuler-22.03-LTS:否
4.openEuler-22.03-LTS-SP1:否
5.openEuler-22.03-LTS-SP2:否
6.openEuler-22.03-LTS-SP3:否
7.master(6.1.0):否
8.openEuler-22.03-LTS-Next:否
9.openEuler-24.03-LTS:否
10.openEuler-24.03-LTS-Next:否
===========================================================
@sanglipeng 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 需分析 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | btrfs: fix double free of anonymous device after snapshot creation failureWhen creating a snapshot we may do a double free of an anonymous devicein case there_x27;s an error committing the transaction. The second free mayresult in freeing an anonymous device number that was allocated by someother subsystem in the kernel or another btrfs filesystem.The steps that lead to this:1) At ioctl.c:create_snapshot() we allocate an anonymous device number and assign it to pending_snapshot->anon_dev;2) Then we call btrfs_commit_transaction() and end up at transaction.c:create_pending_snapshot();3) There we call btrfs_get_new_fs_root() and pass it the anonymous device number stored in pending_snapshot->anon_dev;4) btrfs_get_new_fs_root() frees that anonymous device number because btrfs_lookup_fs_root() returned a root - someone else did a lookup of the new root already, which could some task doing backref walking;5) After that some error happens in the transaction commit path, and at ioctl.c:create_snapshot() we jump to the _x27;fail_x27; label, and after that we free again the same anonymous device number, which in the meanwhile may have been reallocated somewhere else, because pending_snapshot->anon_dev still has the same value as in step 1.Recently syzbot ran into this and reported the following trace: ------------[ cut here ]------------ ida_free called for id=51 which is not allocated. WARNING: CPU: 1 PID: 31038 at lib/idr.c:525 ida_free+0x370/0x420 lib/idr.c:525 Modules linked in: CPU: 1 PID: 31038 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00410-gc02197fc9076 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:ida_free+0x370/0x420 lib/idr.c:525 Code: 10 42 80 3c 28 (...) RSP: 0018:ffffc90015a67300 EFLAGS: 00010246 RAX: be5130472f5dd000 RBX: 0000000000000033 RCX: 0000000000040000 RDX: ffffc90009a7a000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc90015a673f0 R08: ffffffff81577992 R09: 1ffff92002b4cdb4 R10: dffffc0000000000 R11: fffff52002b4cdb5 R12: 0000000000000246 R13: dffffc0000000000 R14: ffffffff8e256b80 R15: 0000000000000246 FS: 00007fca3f4b46c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f167a17b978 CR3: 000000001ed26000 CR4: 0000000000350ef0 Call Trace: <TASK> btrfs_get_root_ref+0xa48/0xaf0 fs/btrfs/disk-io.c:1346 create_pending_snapshot+0xff2/0x2bc0 fs/btrfs/transaction.c:1837 create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1931 btrfs_commit_transaction+0xf1c/0x3740 fs/btrfs/transaction.c:2404 create_snapshot+0x507/0x880 fs/btrfs/ioctl.c:848 btrfs_mksubvol+0x5d0/0x750 fs/btrfs/ioctl.c:998 btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1044 __btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1306 btrfs_ioctl_snap_create_v2+0x1ca/0x400 fs/btrfs/ioctl.c:1393 btrfs_ioctl+0xa74/0xd40 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfe/0x170 fs/ioctl.c:857 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7fca3e67dda9 Code: 28 00 00 00 (...) RSP: 002b:00007fca3f4b40c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fca3e7abf80 RCX: 00007fca3e67dda9 RDX: 00000000200005c0 RSI: 0000000050009417 RDI: 0000000000000003 RBP: 00007fca3e6ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fca3e7abf80 R15: 00007fff6bf95658 </TASK>Where we get an explicit message where we attempt to free an anonymousdevice number that is not currently allocated. It happens in a differentcode path from the example below, at btrfs_get_root_ref(), so this changemay not fix the case triggered by sy---truncated--- |
| 已分析 | 2.openEulerScore | 5.5 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | openEuler-22.03-LTS:受影响,openEuler-22.03-LTS-SP1:受影响,openEuler-22.03-LTS-SP2:受影响,openEuler-22.03-LTS-SP3:受影响,openEuler-20.03-LTS-SP1:不受影响,openEuler-20.03-LTS-SP4:不受影响,master:不受影响,openEuler-22.03-LTS-Next:不受影响,openEuler-24.03-LTS:不受影响,openEuler-24.03-LTS-Next:不受影响 |
| 已分析 | 5.修复是否涉及abi变化 | openEuler-20.03-LTS-SP1:否,openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS:否,openEuler-22.03-LTS-SP1:否,openEuler-22.03-LTS-SP2:否,openEuler-22.03-LTS-SP3:否,master:否,openEuler-22.03-LTS-Next:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-Next:否 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
@成坚 (CHENG Jian) ,@Xie XiuQi ,@YangYingliang ,@pi3orama ,@jiaoff ,@郭梦琪
关闭issue前,需要将受影响的分支在合并pr时关联上当前issue编号: #I9E46G:CVE-2024-26792
受影响分支: openEuler-22.03-LTS-SP3/openEuler-22.03-LTS/openEuler-22.03-LTS-SP1/openEuler-22.03-LTS-SP2
具体操作参考: https://gitee.com/help/articles/4142
CVE-2024-26792
影响性分析说明：
btrfs: fix double free of anonymous device after snapshot creation failure
When creating a snapshot we may do a double free of an anonymous device
in case there_x27;s an error committing the transaction. The second free may
result in freeing an anonymous device number that was allocated by some
other subsystem in the kernel or another btrfs filesystem.
The steps that lead to this:
At ioctl.c:create_snapshot() we allocate an anonymous device number
and assign it to pending_snapshot->anon_dev;
Then we call btrfs_commit_transaction() and end up at
transaction.c:create_pending_snapshot();
There we call btrfs_get_new_fs_root() and pass it the anonymous device
number stored in pending_snapshot->anon_dev;
btrfs_get_new_fs_root() frees that anonymous device number because
btrfs_lookup_fs_root() returned a root - someone else did a lookup
of the new root already, which could some task doing backref walking;
After that some error happens in the transaction commit path, and at
ioctl.c:create_snapshot() we jump to the _x27;fail_x27; label, and after
that we free again the same anonymous device number, which in the
meanwhile may have been reallocated somewhere else, because
pending_snapshot->anon_dev still has the same value as in step 1.
Recently syzbot ran into this and reported the following trace:
------------[ cut here ]------------
ida_free called for id=51 which is not allocated.
WARNING: CPU: 1 PID: 31038 at lib/idr.c:525 ida_free+0x370/0x420 lib/idr.c:525
Modules linked in:
CPU: 1 PID: 31038 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00410-gc02197fc9076 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:ida_free+0x370/0x420 lib/idr.c:525
Code: 10 42 80 3c 28 (...)
RSP: 0018:ffffc90015a67300 EFLAGS: 00010246
RAX: be5130472f5dd000 RBX: 0000000000000033 RCX: 0000000000040000
RDX: ffffc90009a7a000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc90015a673f0 R08: ffffffff81577992 R09: 1ffff92002b4cdb4
R10: dffffc0000000000 R11: fffff52002b4cdb5 R12: 0000000000000246
R13: dffffc0000000000 R14: ffffffff8e256b80 R15: 0000000000000246
FS: 00007fca3f4b46c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f167a17b978 CR3: 000000001ed26000 CR4: 0000000000350ef0
Call Trace:
<TASK>
btrfs_get_root_ref+0xa48/0xaf0 fs/btrfs/disk-io.c:1346
create_pending_snapshot+0xff2/0x2bc0 fs/btrfs/transaction.c:1837
create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1931
btrfs_commit_transaction+0xf1c/0x3740 fs/btrfs/transaction.c:2404
create_snapshot+0x507/0x880 fs/btrfs/ioctl.c:848
btrfs_mksubvol+0x5d0/0x750 fs/btrfs/ioctl.c:998
btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1044
__btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1306
btrfs_ioctl_snap_create_v2+0x1ca/0x400 fs/btrfs/ioctl.c:1393
btrfs_ioctl+0xa74/0xd40
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfe/0x170 fs/ioctl.c:857
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7fca3e67dda9
Code: 28 00 00 00 (...)
RSP: 002b:00007fca3f4b40c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fca3e7abf80 RCX: 00007fca3e67dda9
RDX: 00000000200005c0 RSI: 0000000050009417 RDI: 0000000000000003
RBP: 00007fca3e6ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fca3e7abf80 R15: 00007fff6bf95658
</TASK>
Where we get an explicit message where we attempt to free an anonymous
device number that is not currently allocated. It happens in a different
code path from the example below, at btrfs_get_root_ref(), so this change
may not fix the case triggered by sy
---truncated---
openEuler评分:(评分和向量)
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.openEuler-20.03-LTS-SP1:不受影响
2.openEuler-20.03-LTS-SP4:不受影响
3.openEuler-22.03-LTS:受影响
4.openEuler-22.03-LTS-SP1:受影响
5.openEuler-22.03-LTS-SP2:受影响
6.openEuler-22.03-LTS-SP3:受影响
7.openEuler-22.03-LTS-SP4:不受影响
8.master(6.1.0):不受影响
9.openEuler-22.03-LTS-Next:不受影响
10.openEuler-24.03-LTS:不受影响
11.openEuler-24.03-LTS-Next:不受影响
修复是否涉及abi变化(是/否)：
1.openEuler-20.03-LTS-SP1(4.19.90):否
2.openEuler-20.03-LTS-SP4:否
3.openEuler-22.03-LTS:否
4.openEuler-22.03-LTS-SP1:否
5.openEuler-22.03-LTS-SP2:否
6.openEuler-22.03-LTS-SP3:否
7.master(6.1.0):否
8.openEuler-22.03-LTS-Next:否
9.openEuler-24.03-LTS:否
10.openEuler-24.03-LTS-Next:否
11.openEuler-22.03-LTS-SP4:否
===========================================================
@sanglipeng 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 需分析 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | btrfs: fix double free of anonymous device after snapshot creation failureWhen creating a snapshot we may do a double free of an anonymous devicein case there_x27;s an error committing the transaction. The second free mayresult in freeing an anonymous device number that was allocated by someother subsystem in the kernel or another btrfs filesystem.The steps that lead to this:1) At ioctl.c:create_snapshot() we allocate an anonymous device number and assign it to pending_snapshot->anon_dev;2) Then we call btrfs_commit_transaction() and end up at transaction.c:create_pending_snapshot();3) There we call btrfs_get_new_fs_root() and pass it the anonymous device number stored in pending_snapshot->anon_dev;4) btrfs_get_new_fs_root() frees that anonymous device number because btrfs_lookup_fs_root() returned a root - someone else did a lookup of the new root already, which could some task doing backref walking;5) After that some error happens in the transaction commit path, and at ioctl.c:create_snapshot() we jump to the _x27;fail_x27; label, and after that we free again the same anonymous device number, which in the meanwhile may have been reallocated somewhere else, because pending_snapshot->anon_dev still has the same value as in step 1.Recently syzbot ran into this and reported the following trace: ------------[ cut here ]------------ ida_free called for id=51 which is not allocated. WARNING: CPU: 1 PID: 31038 at lib/idr.c:525 ida_free+0x370/0x420 lib/idr.c:525 Modules linked in: CPU: 1 PID: 31038 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00410-gc02197fc9076 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:ida_free+0x370/0x420 lib/idr.c:525 Code: 10 42 80 3c 28 (...) RSP: 0018:ffffc90015a67300 EFLAGS: 00010246 RAX: be5130472f5dd000 RBX: 0000000000000033 RCX: 0000000000040000 RDX: ffffc90009a7a000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc90015a673f0 R08: ffffffff81577992 R09: 1ffff92002b4cdb4 R10: dffffc0000000000 R11: fffff52002b4cdb5 R12: 0000000000000246 R13: dffffc0000000000 R14: ffffffff8e256b80 R15: 0000000000000246 FS: 00007fca3f4b46c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f167a17b978 CR3: 000000001ed26000 CR4: 0000000000350ef0 Call Trace: <TASK> btrfs_get_root_ref+0xa48/0xaf0 fs/btrfs/disk-io.c:1346 create_pending_snapshot+0xff2/0x2bc0 fs/btrfs/transaction.c:1837 create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1931 btrfs_commit_transaction+0xf1c/0x3740 fs/btrfs/transaction.c:2404 create_snapshot+0x507/0x880 fs/btrfs/ioctl.c:848 btrfs_mksubvol+0x5d0/0x750 fs/btrfs/ioctl.c:998 btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1044 __btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1306 btrfs_ioctl_snap_create_v2+0x1ca/0x400 fs/btrfs/ioctl.c:1393 btrfs_ioctl+0xa74/0xd40 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfe/0x170 fs/ioctl.c:857 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7fca3e67dda9 Code: 28 00 00 00 (...) RSP: 002b:00007fca3f4b40c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fca3e7abf80 RCX: 00007fca3e67dda9 RDX: 00000000200005c0 RSI: 0000000050009417 RDI: 0000000000000003 RBP: 00007fca3e6ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fca3e7abf80 R15: 00007fff6bf95658 </TASK>Where we get an explicit message where we attempt to free an anonymousdevice number that is not currently allocated. It happens in a differentcode path from the example below, at btrfs_get_root_ref(), so this changemay not fix the case triggered by sy---truncated--- |
| 已分析 | 2.openEulerScore | 5.5 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | openEuler-22.03-LTS:受影响,openEuler-22.03-LTS-SP1:受影响,openEuler-22.03-LTS-SP2:受影响,openEuler-22.03-LTS-SP3:受影响,openEuler-20.03-LTS-SP1:不受影响,openEuler-20.03-LTS-SP4:不受影响,openEuler-22.03-LTS-SP4:不受影响,master:不受影响,openEuler-22.03-LTS-Next:不受影响,openEuler-24.03-LTS:不受影响,openEuler-24.03-LTS-Next:不受影响 |
| 已分析 | 5.修复是否涉及abi变化 | openEuler-20.03-LTS-SP1:否,openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS:否,openEuler-22.03-LTS-SP1:否,openEuler-22.03-LTS-SP2:否,openEuler-22.03-LTS-SP3:否,master:否,openEuler-22.03-LTS-Next:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-Next:否,openEuler-22.03-LTS-SP4:否 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
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