CVE-2025-40243
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: hfs: fix KMSAN uninit-value issue in hfs_find_set_zero_bits() The syzbot reported issue in hfs_find_set_zero_bits(): ===================================================== BUG: KMSAN: uninit-value in hfs_find_set_zero_bits+0x74d/0xb60 fs/hfs/bitmap.c:45 hfs_find_set_zero_bits+0x74d/0xb60 fs/hfs/bitmap.c:45 hfs_vbm_search_free+0x13c/0x5b0 fs/hfs/bitmap.c:151 hfs_extend_file+0x6a5/0x1b00 fs/hfs/extent.c:408 hfs_get_block+0x435/0x1150 fs/hfs/extent.c:353 __block_write_begin_int+0xa76/0x3030 fs/buffer.c:2151 block_write_begin fs/buffer.c:2262 [inline] cont_write_begin+0x10e1/0x1bc0 fs/buffer.c:2601 hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52 cont_expand_zero fs/buffer.c:2528 [inline] cont_write_begin+0x35a/0x1bc0 fs/buffer.c:2591 hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52 hfs_file_truncate+0x1d6/0xe60 fs/hfs/extent.c:494 hfs_inode_setattr+0x964/0xaa0 fs/hfs/inode.c:654 notify_change+0x1993/0x1aa0 fs/attr.c:552 do_truncate+0x28f/0x310 fs/open.c:68 do_ftruncate+0x698/0x730 fs/open.c:195 do_sys_ftruncate fs/open.c:210 [inline] __do_sys_ftruncate fs/open.c:215 [inline] __se_sys_ftruncate fs/open.c:213 [inline] __x64_sys_ftruncate+0x11b/0x250 fs/open.c:213 x64_sys_call+0xfe3/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:78 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was created at: slab_post_alloc_hook mm/slub.c:4154 [inline] slab_alloc_node mm/slub.c:4197 [inline] __kmalloc_cache_noprof+0x7f7/0xed0 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] hfs_mdb_get+0x1cc8/0x2a90 fs/hfs/mdb.c:175 hfs_fill_super+0x3d0/0xb80 fs/hfs/super.c:337 get_tree_bdev_flags+0x6e3/0x920 fs/super.c:1681 get_tree_bdev+0x38/0x50 fs/super.c:1704 hfs_get_tree+0x35/0x40 fs/hfs/super.c:388 vfs_get_tree+0xb0/0x5c0 fs/super.c:1804 do_new_mount+0x738/0x1610 fs/namespace.c:3902 path_mount+0x6db/0x1e90 fs/namespace.c:4226 do_mount fs/namespace.c:4239 [inline] __do_sys_mount fs/namespace.c:4450 [inline] __se_sys_mount+0x6eb/0x7d0 fs/namespace.c:4427 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4427 x64_sys_call+0xfa7/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f CPU: 1 UID: 0 PID: 12609 Comm: syz.1.2692 Not tainted 6.16.0-syzkaller #0 PREEMPT(none) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 ===================================================== The HFS_SB(sb)->bitmap buffer is allocated in hfs_mdb_get(): HFS_SB(sb)->bitmap = kmalloc(8192, GFP_KERNEL); Finally, it can trigger the reported issue because kmalloc() doesn't clear the allocated memory. If allocated memory contains only zeros, then everything will work pretty fine. But if the allocated memory contains the "garbage", then it can affect the bitmap operations and it triggers the reported issue. This patch simply exchanges the kmalloc() on kzalloc() with the goal to guarantee the correctness of bitmap operations. Because, newly created allocation bitmap should have all available blocks free. Potentially, initialization bitmap's read operation could not fill the whole allocated memory and "garbage" in the not initialized memory will be the reason of volume coruptions and file system driver bugs.
View original CVE JSON
{
"id": "CVE-2025-40243",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-12-04T16:16:17.523",
"lastModified": "2026-10-19T19:10:00.130",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhfs: fix KMSAN uninit-value issue in hfs_find_set_zero_bits()\n\nThe syzbot reported issue in hfs_find_set_zero_bits():\n\n=====================================================\nBUG: KMSAN: uninit-value in hfs_find_set_zero_bits+0x74d/0xb60 fs/hfs/bitmap.c:45\n hfs_find_set_zero_bits+0x74d/0xb60 fs/hfs/bitmap.c:45\n hfs_vbm_search_free+0x13c/0x5b0 fs/hfs/bitmap.c:151\n hfs_extend_file+0x6a5/0x1b00 fs/hfs/extent.c:408\n hfs_get_block+0x435/0x1150 fs/hfs/extent.c:353\n __block_write_begin_int+0xa76/0x3030 fs/buffer.c:2151\n block_write_begin fs/buffer.c:2262 [inline]\n cont_write_begin+0x10e1/0x1bc0 fs/buffer.c:2601\n hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52\n cont_expand_zero fs/buffer.c:2528 [inline]\n cont_write_begin+0x35a/0x1bc0 fs/buffer.c:2591\n hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52\n hfs_file_truncate+0x1d6/0xe60 fs/hfs/extent.c:494\n hfs_inode_setattr+0x964/0xaa0 fs/hfs/inode.c:654\n notify_change+0x1993/0x1aa0 fs/attr.c:552\n do_truncate+0x28f/0x310 fs/open.c:68\n do_ftruncate+0x698/0x730 fs/open.c:195\n do_sys_ftruncate fs/open.c:210 [inline]\n __do_sys_ftruncate fs/open.c:215 [inline]\n __se_sys_ftruncate fs/open.c:213 [inline]\n __x64_sys_ftruncate+0x11b/0x250 fs/open.c:213\n x64_sys_call+0xfe3/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:78\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nUninit was created at:\n slab_post_alloc_hook mm/slub.c:4154 [inline]\n slab_alloc_node mm/slub.c:4197 [inline]\n __kmalloc_cache_noprof+0x7f7/0xed0 mm/slub.c:4354\n kmalloc_noprof include/linux/slab.h:905 [inline]\n hfs_mdb_get+0x1cc8/0x2a90 fs/hfs/mdb.c:175\n hfs_fill_super+0x3d0/0xb80 fs/hfs/super.c:337\n get_tree_bdev_flags+0x6e3/0x920 fs/super.c:1681\n get_tree_bdev+0x38/0x50 fs/super.c:1704\n hfs_get_tree+0x35/0x40 fs/hfs/super.c:388\n vfs_get_tree+0xb0/0x5c0 fs/super.c:1804\n do_new_mount+0x738/0x1610 fs/namespace.c:3902\n path_mount+0x6db/0x1e90 fs/namespace.c:4226\n do_mount fs/namespace.c:4239 [inline]\n __do_sys_mount fs/namespace.c:4450 [inline]\n __se_sys_mount+0x6eb/0x7d0 fs/namespace.c:4427\n __x64_sys_mount+0xe4/0x150 fs/namespace.c:4427\n x64_sys_call+0xfa7/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:166\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nCPU: 1 UID: 0 PID: 12609 Comm: syz.1.2692 Not tainted 6.16.0-syzkaller #0 PREEMPT(none)\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025\n=====================================================\n\nThe HFS_SB(sb)->bitmap buffer is allocated in hfs_mdb_get():\n\nHFS_SB(sb)->bitmap = kmalloc(8192, GFP_KERNEL);\n\nFinally, it can trigger the reported issue because kmalloc()\ndoesn't clear the allocated memory. If allocated memory contains\nonly zeros, then everything will work pretty fine.\nBut if the allocated memory contains the \"garbage\", then\nit can affect the bitmap operations and it triggers\nthe reported issue.\n\nThis patch simply exchanges the kmalloc() on kzalloc()\nwith the goal to guarantee the correctness of bitmap operations.\nBecause, newly created allocation bitmap should have all\navailable blocks free. Potentially, initialization bitmap's read\noperation could not fill the whole allocated memory and\n\"garbage\" in the not initialized memory will be the reason of\nvolume coruptions and file system driver bugs."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nhfs: corrige el problema de valor no inicializado de KMSAN en hfs_find_set_zero_bits()\n\nEl problema reportado por syzbot en hfs_find_set_zero_bits():\n\n=====================================================\nBUG: KMSAN: uninit-value in hfs_find_set_zero_bits+0x74d/0xb60 fs/hfs/bitmap.c:45\n hfs_find_set_zero_bits+0x74d/0xb60 fs/hfs/bitmap.c:45\n hfs_vbm_search_free+0x13c/0x5b0 fs/hfs/bitmap.c:151\n hfs_extend_file+0x6a5/0x1b00 fs/hfs/extent.c:408\n hfs_get_block+0x435/0x1150 fs/hfs/extent.c:353\n __block_write_begin_int+0xa76/0x3030 fs/buffer.c:2151\n block_write_begin fs/buffer.c:2262 [inline]\n cont_write_begin+0x10e1/0x1bc0 fs/buffer.c:2601\n hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52\n cont_expand_zero fs/buffer.c:2528 [inline]\n cont_write_begin+0x35a/0x1bc0 fs/buffer.c:2591\n hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52\n hfs_file_truncate+0x1d6/0xe60 fs/hfs/extent.c:494\n hfs_inode_setattr+0x964/0xaa0 fs/hfs/inode.c:654\n notify_change+0x1993/0x1aa0 fs/attr.c:552\n do_truncate+0x28f/0x310 fs/open.c:68\n do_ftruncate+0x698/0x730 fs/open.c:195\n do_sys_ftruncate fs/open.c:210 [inline]\n __do_sys_ftruncate fs/open.c:215 [inline]\n __se_sys_ftruncate fs/open.c:213 [inline]\n __x64_sys_ftruncate+0x11b/0x250 fs/open.c:213\n x64_sys_call+0xfe3/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:78\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nEl valor no inicializado se originó en:\n slab_post_alloc_hook mm/slub.c:4154 [inline]\n slab_alloc_node mm/slub.c:4197 [inline]\n __kmalloc_cache_noprof+0x7f7/0xed0 mm/slub.c:4354\n kmalloc_noprof include/linux/slab.h:905 [inline]\n hfs_mdb_get+0x1cc8/0x2a90 fs/hfs/mdb.c:175\n hfs_fill_super+0x3d0/0xb80 fs/hfs/super.c:337\n get_tree_bdev_flags+0x6e3/0x920 fs/super.c:1681\n get_tree_bdev+0x38/0x50 fs/super.c:1704\n hfs_get_tree+0x35/0x40 fs/hfs/super.c:388\n vfs_get_tree+0xb0/0x5c0 fs/super.c:1804\n do_new_mount+0x738/0x1610 fs/namespace.c:3902\n path_mount+0x6db/0x1e90 fs/namespace.c:4226\n do_mount fs/namespace.c:4239 [inline]\n __do_sys_mount fs/namespace.c:4450 [inline]\n __se_sys_mount+0x6eb/0x7d0 fs/namespace.c:4427\n __x64_sys_mount+0xe4/0x150 fs/namespace.c:4427\n x64_sys_call+0xfa7/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:166\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nCPU: 1 UID: 0 PID: 12609 Comm: syz.1.2692 Not tainted 6.16.0-syzkaller #0 PREEMPT(none)\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025\n=====================================================\n\nEl búfer HFS_SB(sb) -> bitmap se asigna en hfs_mdb_get():\n\nHFS_SB(sb) -> bitmap = kmalloc(8192, GFP_KERNEL);\n\nFinalmente, puede desencadenar el problema reportado porque kmalloc() no limpia la memoria asignada. Si la memoria asignada contiene solo ceros, entonces todo funcionará bastante bien. Pero si la memoria asignada contiene “basura”, entonces puede afectar las operaciones de mapa de bits y desencadena el problema reportado.\n\nEste parche simplemente intercambia kmalloc() por kzalloc() con el objetivo de garantizar la corrección de las operaciones de mapa de bits. Porque, un mapa de bits de asignación recién creado debería tener todos los bloques disponibles libres. Potencialmente, la operación de lectura del mapa de bits de inicialización podría no llenar toda la memoria asignada y la “basura” en la memoria no inicializada será la causa de corrupciones de volumen y errores del controlador del sistema de archivos."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"fs/hfs/mdb.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "fc56548fca732f3d3692c83b40db796259a03887",
"versionType": "git",
"status": "affected"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "bf1683078fbdd09a7f7f9b74121ebaa03432bd00",
"versionType": "git",
"status": "affected"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "2a112cdd66f5a132da5235ca31a320528c86bf33",
"versionType": "git",
"status": "affected"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "e148ed5cda8fd96d4620c4622fb02f552a2d166a",
"versionType": "git",
"status": "affected"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "cfafefcb0e1fc60135f7040f4aed0a4aef4f76ca",
"versionType": "git",
"status": "affected"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "3b447fd401824e1ccf0b769188edefe866a1e676",
"versionType": "git",
"status": "affected"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "502fa92a71f344611101bd04ef1a595b8b6014f5",
"versionType": "git",
"status": "affected"
},
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "2048ec5b98dbdfe0b929d2e42dc7a54c389c53dd",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"fs/hfs/mdb.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "2.6.12",
"status": "affected"
},
{
"version": "0",
"lessThan": "2.6.12",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.4.301",
"lessThanOrEqual": "5.4.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.246",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.196",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.158",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.115",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.56",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.17.6",
"lessThanOrEqual": "6.17.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/2048ec5b98dbdfe0b929d2e42dc7a54c389c53dd",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/2a112cdd66f5a132da5235ca31a320528c86bf33",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/3b447fd401824e1ccf0b769188edefe866a1e676",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/502fa92a71f344611101bd04ef1a595b8b6014f5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/bf1683078fbdd09a7f7f9b74121ebaa03432bd00",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/cfafefcb0e1fc60135f7040f4aed0a4aef4f76ca",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e148ed5cda8fd96d4620c4622fb02f552a2d166a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fc56548fca732f3d3692c83b40db796259a03887",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}