{"id":"AZL-66620","summary":"CVE-2025-38650 affecting package kernel for versions less than 6.6.104.2-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nhfsplus: remove mutex_lock check in hfsplus_free_extents\n\nSyzbot reported an issue in hfsplus filesystem:\n\n------------[ cut here ]------------\nWARNING: CPU: 0 PID: 4400 at fs/hfsplus/extents.c:346\n\thfsplus_free_extents+0x700/0xad0\nCall Trace:\n\u003cTASK\u003e\nhfsplus_file_truncate+0x768/0xbb0 fs/hfsplus/extents.c:606\nhfsplus_write_begin+0xc2/0xd0 fs/hfsplus/inode.c:56\ncont_expand_zero fs/buffer.c:2383 [inline]\ncont_write_begin+0x2cf/0x860 fs/buffer.c:2446\nhfsplus_write_begin+0x86/0xd0 fs/hfsplus/inode.c:52\ngeneric_cont_expand_simple+0x151/0x250 fs/buffer.c:2347\nhfsplus_setattr+0x168/0x280 fs/hfsplus/inode.c:263\nnotify_change+0xe38/0x10f0 fs/attr.c:420\ndo_truncate+0x1fb/0x2e0 fs/open.c:65\ndo_sys_ftruncate+0x2eb/0x380 fs/open.c:193\ndo_syscall_x64 arch/x86/entry/common.c:50 [inline]\ndo_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80\nentry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nTo avoid deadlock, Commit 31651c607151 (\"hfsplus: avoid deadlock\non file truncation\") unlock extree before hfsplus_free_extents(),\nand add check wheather extree is locked in hfsplus_free_extents().\n\nHowever, when operations such as hfsplus_file_release,\nhfsplus_setattr, hfsplus_unlink, and hfsplus_get_block are executed\nconcurrently in different files, it is very likely to trigger the\nWARN_ON, which will lead syzbot and xfstest to consider it as an\nabnormality.\n\nThe comment above this warning also describes one of the easy\ntriggering situations, which can easily trigger and cause\nxfstest&syzbot to report errors.\n\n[task A]\t\t\t[task B]\n-\u003ehfsplus_file_release\n  -\u003ehfsplus_file_truncate\n    -\u003ehfs_find_init\n      -\u003emutex_lock\n    -\u003emutex_unlock\n\t\t\t\t-\u003ehfsplus_write_begin\n\t\t\t\t  -\u003ehfsplus_get_block\n\t\t\t\t    -\u003ehfsplus_file_extend\n\t\t\t\t      -\u003ehfsplus_ext_read_extent\n\t\t\t\t        -\u003ehfs_find_init\n\t\t\t\t\t  -\u003emutex_lock\n    -\u003ehfsplus_free_extents\n      WARN_ON(mutex_is_locked) !!!\n\nSeveral threads could try to lock the shared extents tree.\nAnd warning can be triggered in one thread when another thread\nhas locked the tree. This is the wrong behavior of the code and\nwe need to remove the warning.","modified":"2026-04-01T05:21:00.951059Z","published":"2025-08-22T16:15:39Z","upstream":["CVE-2025-38650"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38650"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.104.2-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-66620.json"}}],"schema_version":"1.7.5"}