Microsoft security update for CVE-2025-38650 — azl3 kernel
🔗 CVE IDs covered (1)
📋 Microsoft's advisory
EchelonGraph does not copy Microsoft's advisory page: its FAQ and remediation text are not shown here. Read the advisory on https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-38650. This page also shows what EchelonGraph holds for CVE-2025-38650, with the description from its CVE record, which the CVE Numbering Authority that assigned the CVE wrote: for a CVE Microsoft assigned, often in the words of Microsoft's own advisory.
🎯 Affected products2
- azl3 kernel 6.6.96.2-1 on Azure Linux 3.0
- azl3 kernel 6.6.96.2-2 on Azure Linux 3.0
✅ Updates Microsoft lists: 1 update
1 row: one per KB article or update, update type and fixed build. Their details are on Microsoft's advisory.
| KB article | Update | Fixed build |
|---|---|---|
| — | Security Update | 6.6.104.2-1 |
🧭 EchelonGraph on CVE-2025-38650
- EchelonGraph score
- 5.5 MEDIUM
- CISA KEV
- Not listed
- Fix status
- A fix is available — apply it.
Description from the CVE record (CVE.org), as published by its numbering authority
In the Linux kernel, the following vulnerability has been resolved: hfsplus: remove mutex_lock check in hfsplus_free_extents Syzbot reported an issue in hfsplus filesystem: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 4400 at fs/hfsplus/extents.c:346 hfsplus_free_extents+0x700/0xad0 Call Trace: <TASK> hfsplus_file_truncate+0x768/0xbb0 fs/hfsplus/extents.c:606 hfsplus_write_begin+0xc2/0xd0 fs/hfsplus/inode.c:56 cont_expand_zero fs/buffer.c:2383 [inline] cont_write_begin+0x2cf/0x860 fs/buffer.c:2446 hfsplus_write_begin+0x86/0xd0 fs/hfsplus/inode.c:52 generic_cont_expand_simple+0x151/0x250 fs/buffer.c:2347 hfsplus_setattr+0x168/0x280 fs/hfsplus/inode.c:263 notify_change+0xe38/0x10f0 fs/attr.c:420 do_truncate+0x1fb/0x2e0 fs/open.c:65 do_sys_ftruncate+0x2eb/0x380 fs/open.c:193 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd To avoid deadlock, Commit 31651c607151 ("hfsplus: avoid deadlock on file truncation") unlock extree before hfsplus_free_extents(), and add check wheather extree is locked in hfsplus_free_extents(). However, when operations such as hfsplus_file_release, hfsplus_setattr, hfsplus_unlink, and hfsplus_get_block are executed concurrently in different files, it is very likely to trigger the WARN_ON, which will lead syzbot and xfstest to consider it as an abnormality. The comment above this warning also describes one of the easy triggering situations, which can easily trigger and cause xfstest&syzbot to report errors. [task A] [task B] ->hfsplus_file_release ->hfsplus_file_truncate ->hfs_find_init ->mutex_lock ->mutex_unlock ->hfsplus_write_begin ->hfsplus_get_block ->hfsplus_file_extend ->hfsplus_ext_read_extent ->hfs_find_init ->mutex_lock ->hfsplus_free_extents WARN_ON(mutex_is_locked) !!! Several threads could try to lock the shared extents tree. And warning can be triggered in one thread when another thread has locked the tree. This is the wrong behavior of the code and we need to remove the warning.
Published by kernel.org, the CVE Numbering Authority that assigned CVE-2025-38650, in its CVE record at CVE.org; reused under the CVE Program's Terms of Use (its licence and MITRE's copyright notice are in our Terms of Service).