[PATCH 5.4 171/224] hfsplus: fix slab-out-of-bounds read in hfsplus_strcasecmp()

[PATCH 5.4 171/224] hfsplus: fix slab-out-of-bounds read in hfsplus_strcasecmp()

[Greg Kroah-Hartman]

5.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Viacheslav Dubeyko <slava@dubeyko.com>

commit 42520df65bf67189541a425f7d36b0b3e7bd7844 upstream.

The hfsplus_strcasecmp() logic can trigger the issue:

[  117.317703][ T9855] ==================================================================
[  117.318353][ T9855] BUG: KASAN: slab-out-of-bounds in hfsplus_strcasecmp+0x1bc/0x490
[  117.318991][ T9855] Read of size 2 at addr ffff88802160f40c by task repro/9855
[  117.319577][ T9855]
[  117.319773][ T9855] CPU: 0 UID: 0 PID: 9855 Comm: repro Not tainted 6.17.0-rc6 #33 PREEMPT(full)
[  117.319780][ T9855] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  117.319783][ T9855] Call Trace:
[  117.319785][ T9855]  <TASK>
[  117.319788][ T9855]  dump_stack_lvl+0x1c1/0x2a0
[  117.319795][ T9855]  ? __virt_addr_valid+0x1c8/0x5c0
[  117.319803][ T9855]  ? __pfx_dump_stack_lvl+0x10/0x10
[  117.319808][ T9855]  ? rcu_is_watching+0x15/0xb0
[  117.319816][ T9855]  ? lock_release+0x4b/0x3e0
[  117.319821][ T9855]  ? __kasan_check_byte+0x12/0x40
[  117.319828][ T9855]  ? __virt_addr_valid+0x1c8/0x5c0
[  117.319835][ T9855]  ? __virt_addr_valid+0x4a5/0x5c0
[  117.319842][ T9855]  print_report+0x17e/0x7e0
[  117.319848][ T9855]  ? __virt_addr_valid+0x1c8/0x5c0
[  117.319855][ T9855]  ? __virt_addr_valid+0x4a5/0x5c0
[  117.319862][ T9855]  ? __phys_addr+0xd3/0x180
[  117.319869][ T9855]  ? hfsplus_strcasecmp+0x1bc/0x490
[  117.319876][ T9855]  kasan_report+0x147/0x180
[  117.319882][ T9855]  ? hfsplus_strcasecmp+0x1bc/0x490
[  117.319891][ T9855]  hfsplus_strcasecmp+0x1bc/0x490
[  117.319900][ T9855]  ? __pfx_hfsplus_cat_case_cmp_key+0x10/0x10
[  117.319906][ T9855]  hfs_find_rec_by_key+0xa9/0x1e0
[  117.319913][ T9855]  __hfsplus_brec_find+0x18e/0x470
[  117.319920][ T9855]  ? __pfx_hfsplus_bnode_find+0x10/0x10
[  117.319926][ T9855]  ? __pfx_hfs_find_rec_by_key+0x10/0x10
[  117.319933][ T9855]  ? __pfx___hfsplus_brec_find+0x10/0x10
[  117.319942][ T9855]  hfsplus_brec_find+0x28f/0x510
[  117.319949][ T9855]  ? __pfx_hfs_find_rec_by_key+0x10/0x10
[  117.319956][ T9855]  ? __pfx_hfsplus_brec_find+0x10/0x10
[  117.319963][ T9855]  ? __kmalloc_noprof+0x2a9/0x510
[  117.319969][ T9855]  ? hfsplus_find_init+0x8c/0x1d0
[  117.319976][ T9855]  hfsplus_brec_read+0x2b/0x120
[  117.319983][ T9855]  hfsplus_lookup+0x2aa/0x890
[  117.319990][ T9855]  ? __pfx_hfsplus_lookup+0x10/0x10
[  117.320003][ T9855]  ? d_alloc_parallel+0x2f0/0x15e0
[  117.320008][ T9855]  ? __lock_acquire+0xaec/0xd80
[  117.320013][ T9855]  ? __pfx_d_alloc_parallel+0x10/0x10
[  117.320019][ T9855]  ? __raw_spin_lock_init+0x45/0x100
[  117.320026][ T9855]  ? __init_waitqueue_head+0xa9/0x150
[  117.320034][ T9855]  __lookup_slow+0x297/0x3d0
[  117.320039][ T9855]  ? __pfx___lookup_slow+0x10/0x10
[  117.320045][ T9855]  ? down_read+0x1ad/0x2e0
[  117.320055][ T9855]  lookup_slow+0x53/0x70
[  117.320065][ T9855]  walk_component+0x2f0/0x430
[  117.320073][ T9855]  path_lookupat+0x169/0x440
[  117.320081][ T9855]  filename_lookup+0x212/0x590
[  117.320089][ T9855]  ? __pfx_filename_lookup+0x10/0x10
[  117.320098][ T9855]  ? strncpy_from_user+0x150/0x290
[  117.320105][ T9855]  ? getname_flags+0x1e5/0x540
[  117.320112][ T9855]  user_path_at+0x3a/0x60
[  117.320117][ T9855]  __x64_sys_umount+0xee/0x160
[  117.320123][ T9855]  ? __pfx___x64_sys_umount+0x10/0x10
[  117.320129][ T9855]  ? do_syscall_64+0xb7/0x3a0
[  117.320135][ T9855]  ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[  117.320141][ T9855]  ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[  117.320145][ T9855]  do_syscall_64+0xf3/0x3a0
[  117.320150][ T9855]  ? exc_page_fault+0x9f/0xf0
[  117.320154][ T9855]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[  117.320158][ T9855] RIP: 0033:0x7f7dd7908b07
[  117.320163][ T9855] Code: 23 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 08
[  117.320167][ T9855] RSP: 002b:00007ffd5ebd9698 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
[  117.320172][ T9855] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7dd7908b07
[  117.320176][ T9855] RDX: 0000000000000009 RSI: 0000000000000009 RDI: 00007ffd5ebd9740
[  117.320179][ T9855] RBP: 00007ffd5ebda780 R08: 0000000000000005 R09: 00007ffd5ebd9530
[  117.320181][ T9855] R10: 00007f7dd799bfc0 R11: 0000000000000202 R12: 000055e2008b32d0
[  117.320184][ T9855] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[  117.320189][ T9855]  </TASK>
[  117.320190][ T9855]
[  117.351311][ T9855] Allocated by task 9855:
[  117.351683][ T9855]  kasan_save_track+0x3e/0x80
[  117.352093][ T9855]  __kasan_kmalloc+0x8d/0xa0
[  117.352490][ T9855]  __kmalloc_noprof+0x288/0x510
[  117.352914][ T9855]  hfsplus_find_init+0x8c/0x1d0
[  117.353342][ T9855]  hfsplus_lookup+0x19c/0x890
[  117.353747][ T9855]  __lookup_slow+0x297/0x3d0
[  117.354148][ T9855]  lookup_slow+0x53/0x70
[  117.354514][ T9855]  walk_component+0x2f0/0x430
[  117.354921][ T9855]  path_lookupat+0x169/0x440
[  117.355325][ T9855]  filename_lookup+0x212/0x590
[  117.355740][ T9855]  user_path_at+0x3a/0x60
[  117.356115][ T9855]  __x64_sys_umount+0xee/0x160
[  117.356529][ T9855]  do_syscall_64+0xf3/0x3a0
[  117.356920][ T9855]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[  117.357429][ T9855]
[  117.357636][ T9855] The buggy address belongs to the object at ffff88802160f000
[  117.357636][ T9855]  which belongs to the cache kmalloc-2k of size 2048
[  117.358827][ T9855] The buggy address is located 0 bytes to the right of
[  117.358827][ T9855]  allocated 1036-byte region [ffff88802160f000, ffff88802160f40c)
[  117.360061][ T9855]
[  117.360266][ T9855] The buggy address belongs to the physical page:
[  117.360813][ T9855] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21608
[  117.361562][ T9855] head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[  117.362285][ T9855] flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
[  117.362929][ T9855] page_type: f5(slab)
[  117.363282][ T9855] raw: 00fff00000000040 ffff88801a842f00 ffffea0000932000 dead000000000002
[  117.364015][ T9855] raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
[  117.364750][ T9855] head: 00fff00000000040 ffff88801a842f00 ffffea0000932000 dead000000000002
[  117.365491][ T9855] head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
[  117.366232][ T9855] head: 00fff00000000003 ffffea0000858201 00000000ffffffff 00000000ffffffff
[  117.366968][ T9855] head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
[  117.367711][ T9855] page dumped because: kasan: bad access detected
[  117.368259][ T9855] page_owner tracks the page as allocated
[  117.368745][ T9855] page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN1
[  117.370541][ T9855]  post_alloc_hook+0x240/0x2a0
[  117.370954][ T9855]  get_page_from_freelist+0x2101/0x21e0
[  117.371435][ T9855]  __alloc_frozen_pages_noprof+0x274/0x380
[  117.371935][ T9855]  alloc_pages_mpol+0x241/0x4b0
[  117.372360][ T9855]  allocate_slab+0x8d/0x380
[  117.372752][ T9855]  ___slab_alloc+0xbe3/0x1400
[  117.373159][ T9855]  __kmalloc_cache_noprof+0x296/0x3d0
[  117.373621][ T9855]  nexthop_net_init+0x75/0x100
[  117.374038][ T9855]  ops_init+0x35c/0x5c0
[  117.374400][ T9855]  setup_net+0x10c/0x320
[  117.374768][ T9855]  copy_net_ns+0x31b/0x4d0
[  117.375156][ T9855]  create_new_namespaces+0x3f3/0x720
[  117.375613][ T9855]  unshare_nsproxy_namespaces+0x11c/0x170
[  117.376094][ T9855]  ksys_unshare+0x4ca/0x8d0
[  117.376477][ T9855]  __x64_sys_unshare+0x38/0x50
[  117.376879][ T9855]  do_syscall_64+0xf3/0x3a0
[  117.377265][ T9855] page last free pid 9110 tgid 9110 stack trace:
[  117.377795][ T9855]  __free_frozen_pages+0xbeb/0xd50
[  117.378229][ T9855]  __put_partials+0x152/0x1a0
[  117.378625][ T9855]  put_cpu_partial+0x17c/0x250
[  117.379026][ T9855]  __slab_free+0x2d4/0x3c0
[  117.379404][ T9855]  qlist_free_all+0x97/0x140
[  117.379790][ T9855]  kasan_quarantine_reduce+0x148/0x160
[  117.380250][ T9855]  __kasan_slab_alloc+0x22/0x80
[  117.380662][ T9855]  __kmalloc_noprof+0x232/0x510
[  117.381074][ T9855]  tomoyo_supervisor+0xc0a/0x1360
[  117.381498][ T9855]  tomoyo_env_perm+0x149/0x1e0
[  117.381903][ T9855]  tomoyo_find_next_domain+0x15ad/0x1b90
[  117.382378][ T9855]  tomoyo_bprm_check_security+0x11c/0x180
[  117.382859][ T9855]  security_bprm_check+0x89/0x280
[  117.383289][ T9855]  bprm_execve+0x8f1/0x14a0
[  117.383673][ T9855]  do_execveat_common+0x528/0x6b0
[  117.384103][ T9855]  __x64_sys_execve+0x94/0xb0
[  117.384500][ T9855]
[  117.384706][ T9855] Memory state around the buggy address:
[  117.385179][ T9855]  ffff88802160f300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  117.385854][ T9855]  ffff88802160f380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  117.386534][ T9855] >ffff88802160f400: 00 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  117.387204][ T9855]                       ^
[  117.387566][ T9855]  ffff88802160f480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  117.388243][ T9855]  ffff88802160f500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  117.388918][ T9855] ==================================================================

The issue takes place if the length field of struct hfsplus_unistr
is bigger than HFSPLUS_MAX_STRLEN. The patch simply checks
the length of comparing strings. And if the strings' length
is bigger than HFSPLUS_MAX_STRLEN, then it is corrected
to this value.

v2
The string length correction has been added for hfsplus_strcmp().

Reported-by: Jiaming Zhang <r772577952@gmail.com>
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
cc: Yangtao Li <frank.li@vivo.com>
cc: linux-fsdevel@vger.kernel.org
cc: syzkaller@googlegroups.com
Link: https://lore.kernel.org/r/20250919191243.1370388-1-slava@dubeyko.com
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/hfsplus/unicode.c |   24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

--- a/fs/hfsplus/unicode.c
+++ b/fs/hfsplus/unicode.c
@@ -40,6 +40,18 @@ int hfsplus_strcasecmp(const struct hfsp
 	p1 = s1->unicode;
 	p2 = s2->unicode;
 
+	if (len1 > HFSPLUS_MAX_STRLEN) {
+		len1 = HFSPLUS_MAX_STRLEN;
+		pr_err("invalid length %u has been corrected to %d\n",
+			be16_to_cpu(s1->length), len1);
+	}
+
+	if (len2 > HFSPLUS_MAX_STRLEN) {
+		len2 = HFSPLUS_MAX_STRLEN;
+		pr_err("invalid length %u has been corrected to %d\n",
+			be16_to_cpu(s2->length), len2);
+	}
+
 	while (1) {
 		c1 = c2 = 0;
 
@@ -74,6 +86,18 @@ int hfsplus_strcmp(const struct hfsplus_
 	p1 = s1->unicode;
 	p2 = s2->unicode;
 
+	if (len1 > HFSPLUS_MAX_STRLEN) {
+		len1 = HFSPLUS_MAX_STRLEN;
+		pr_err("invalid length %u has been corrected to %d\n",
+			be16_to_cpu(s1->length), len1);
+	}
+
+	if (len2 > HFSPLUS_MAX_STRLEN) {
+		len2 = HFSPLUS_MAX_STRLEN;
+		pr_err("invalid length %u has been corrected to %d\n",
+			be16_to_cpu(s2->length), len2);
+	}
+
 	for (len = min(len1, len2); len > 0; len--) {
 		c1 = be16_to_cpu(*p1);
 		c2 = be16_to_cpu(*p2);

[PATCH 5.4 173/224] hfs: clear offset and space out of valid records in b-tree node

[Greg Kroah-Hartman]

5.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Viacheslav Dubeyko <slava@dubeyko.com>

[ Upstream commit 18b07c44f245beb03588b00b212b38fce9af7cc9 ]

Currently, hfs_brec_remove() executes moving records
towards the location of deleted record and it updates
offsets of moved records. However, the hfs_brec_remove()
logic ignores the "mess" of b-tree node's free space and
it doesn't touch the offsets out of records number.
Potentially, it could confuse fsck or driver logic or
to be a reason of potential corruption cases.

This patch reworks the logic of hfs_brec_remove()
by means of clearing freed space of b-tree node
after the records moving. And it clear the last
offset that keeping old location of free space
because now the offset before this one is keeping
the actual offset to the free space after the record
deletion.

Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
cc: Yangtao Li <frank.li@vivo.com>
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20250815194918.38165-1-slava@dubeyko.com
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/hfs/brec.c | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/fs/hfs/brec.c b/fs/hfs/brec.c
index 896396554bcc1..b01db1fae147c 100644
--- a/fs/hfs/brec.c
+++ b/fs/hfs/brec.c
@@ -179,6 +179,7 @@ int hfs_brec_remove(struct hfs_find_data *fd)
 	struct hfs_btree *tree;
 	struct hfs_bnode *node, *parent;
 	int end_off, rec_off, data_off, size;
+	int src, dst, len;
 
 	tree = fd->tree;
 	node = fd->bnode;
@@ -208,10 +209,14 @@ int hfs_brec_remove(struct hfs_find_data *fd)
 	}
 	hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
 
-	if (rec_off == end_off)
-		goto skip;
 	size = fd->keylength + fd->entrylength;
 
+	if (rec_off == end_off) {
+		src = fd->keyoffset;
+		hfs_bnode_clear(node, src, size);
+		goto skip;
+	}
+
 	do {
 		data_off = hfs_bnode_read_u16(node, rec_off);
 		hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
@@ -219,9 +224,23 @@ int hfs_brec_remove(struct hfs_find_data *fd)
 	} while (rec_off >= end_off);
 
 	/* fill hole */
-	hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
-		       data_off - fd->keyoffset - size);
+	dst = fd->keyoffset;
+	src = fd->keyoffset + size;
+	len = data_off - src;
+
+	hfs_bnode_move(node, dst, src, len);
+
+	src = dst + len;
+	len = data_off - src;
+
+	hfs_bnode_clear(node, src, len);
+
 skip:
+	/*
+	 * Remove the obsolete offset to free space.
+	 */
+	hfs_bnode_write_u16(node, end_off, 0);
+
 	hfs_bnode_dump(node);
 	if (!fd->record)
 		hfs_brec_update_parent(fd);
-- 
2.51.0

[PATCH 5.4 174/224] hfs: make proper initalization of struct hfs_find_data

[Greg Kroah-Hartman]

5.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Viacheslav Dubeyko <slava@dubeyko.com>

[ Upstream commit c62663a986acee7c4485c1fa9de5fc40194b6290 ]

Potenatially, __hfs_ext_read_extent() could operate by
not initialized values of fd->key after hfs_brec_find() call:

static inline int __hfs_ext_read_extent(struct hfs_find_data *fd, struct hfs_extent *extent,
                                        u32 cnid, u32 block, u8 type)
{
        int res;

        hfs_ext_build_key(fd->search_key, cnid, block, type);
        fd->key->ext.FNum = 0;
        res = hfs_brec_find(fd);
        if (res && res != -ENOENT)
                return res;
        if (fd->key->ext.FNum != fd->search_key->ext.FNum ||
            fd->key->ext.FkType != fd->search_key->ext.FkType)
                return -ENOENT;
        if (fd->entrylength != sizeof(hfs_extent_rec))
                return -EIO;
        hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfs_extent_rec));
        return 0;
}

This patch changes kmalloc() on kzalloc() in hfs_find_init()
and intializes fd->record, fd->keyoffset, fd->keylength,
fd->entryoffset, fd->entrylength for the case if hfs_brec_find()
has been found nothing in the b-tree node.

Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
cc: Yangtao Li <frank.li@vivo.com>
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20250818225252.126427-1-slava@dubeyko.com
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/hfs/bfind.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/hfs/bfind.c b/fs/hfs/bfind.c
index ef9498a6e88ac..6d37b4c759034 100644
--- a/fs/hfs/bfind.c
+++ b/fs/hfs/bfind.c
@@ -18,7 +18,7 @@ int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd)
 
 	fd->tree = tree;
 	fd->bnode = NULL;
-	ptr = kmalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
+	ptr = kzalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
 	if (!ptr)
 		return -ENOMEM;
 	fd->search_key = ptr;
@@ -112,6 +112,12 @@ int hfs_brec_find(struct hfs_find_data *fd)
 	__be32 data;
 	int height, res;
 
+	fd->record = -1;
+	fd->keyoffset = -1;
+	fd->keylength = -1;
+	fd->entryoffset = -1;
+	fd->entrylength = -1;
+
 	tree = fd->tree;
 	if (fd->bnode)
 		hfs_bnode_put(fd->bnode);
-- 
2.51.0

[PATCH 5.4 175/224] hfsplus: fix KMSAN uninit-value issue in __hfsplus_ext_cache_extent()

[Greg Kroah-Hartman]

5.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Viacheslav Dubeyko <slava@dubeyko.com>

[ Upstream commit 4840ceadef4290c56cc422f0fc697655f3cbf070 ]

The syzbot reported issue in __hfsplus_ext_cache_extent():

[   70.194323][ T9350] BUG: KMSAN: uninit-value in __hfsplus_ext_cache_extent+0x7d0/0x990
[   70.195022][ T9350]  __hfsplus_ext_cache_extent+0x7d0/0x990
[   70.195530][ T9350]  hfsplus_file_extend+0x74f/0x1cf0
[   70.195998][ T9350]  hfsplus_get_block+0xe16/0x17b0
[   70.196458][ T9350]  __block_write_begin_int+0x962/0x2ce0
[   70.196959][ T9350]  cont_write_begin+0x1000/0x1950
[   70.197416][ T9350]  hfsplus_write_begin+0x85/0x130
[   70.197873][ T9350]  generic_perform_write+0x3e8/0x1060
[   70.198374][ T9350]  __generic_file_write_iter+0x215/0x460
[   70.198892][ T9350]  generic_file_write_iter+0x109/0x5e0
[   70.199393][ T9350]  vfs_write+0xb0f/0x14e0
[   70.199771][ T9350]  ksys_write+0x23e/0x490
[   70.200149][ T9350]  __x64_sys_write+0x97/0xf0
[   70.200570][ T9350]  x64_sys_call+0x3015/0x3cf0
[   70.201065][ T9350]  do_syscall_64+0xd9/0x1d0
[   70.201506][ T9350]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.202054][ T9350]
[   70.202279][ T9350] Uninit was created at:
[   70.202693][ T9350]  __kmalloc_noprof+0x621/0xf80
[   70.203149][ T9350]  hfsplus_find_init+0x8d/0x1d0
[   70.203602][ T9350]  hfsplus_file_extend+0x6ca/0x1cf0
[   70.204087][ T9350]  hfsplus_get_block+0xe16/0x17b0
[   70.204561][ T9350]  __block_write_begin_int+0x962/0x2ce0
[   70.205074][ T9350]  cont_write_begin+0x1000/0x1950
[   70.205547][ T9350]  hfsplus_write_begin+0x85/0x130
[   70.206017][ T9350]  generic_perform_write+0x3e8/0x1060
[   70.206519][ T9350]  __generic_file_write_iter+0x215/0x460
[   70.207042][ T9350]  generic_file_write_iter+0x109/0x5e0
[   70.207552][ T9350]  vfs_write+0xb0f/0x14e0
[   70.207961][ T9350]  ksys_write+0x23e/0x490
[   70.208375][ T9350]  __x64_sys_write+0x97/0xf0
[   70.208810][ T9350]  x64_sys_call+0x3015/0x3cf0
[   70.209255][ T9350]  do_syscall_64+0xd9/0x1d0
[   70.209680][ T9350]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.210230][ T9350]
[   70.210454][ T9350] CPU: 2 UID: 0 PID: 9350 Comm: repro Not tainted 6.12.0-rc5 #5
[   70.211174][ T9350] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   70.212115][ T9350] =====================================================
[   70.212734][ T9350] Disabling lock debugging due to kernel taint
[   70.213284][ T9350] Kernel panic - not syncing: kmsan.panic set ...
[   70.213858][ T9350] CPU: 2 UID: 0 PID: 9350 Comm: repro Tainted: G    B              6.12.0-rc5 #5
[   70.214679][ T9350] Tainted: [B]=BAD_PAGE
[   70.215057][ T9350] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   70.215999][ T9350] Call Trace:
[   70.216309][ T9350]  <TASK>
[   70.216585][ T9350]  dump_stack_lvl+0x1fd/0x2b0
[   70.217025][ T9350]  dump_stack+0x1e/0x30
[   70.217421][ T9350]  panic+0x502/0xca0
[   70.217803][ T9350]  ? kmsan_get_metadata+0x13e/0x1c0

[   70.218294][ Message fromT sy9350]  kmsan_report+0x296/slogd@syzkaller 0x2aat Aug 18 22:11:058 ...
 kernel
:[   70.213284][ T9350] Kernel panic - not syncing: kmsan.panic [   70.220179][ T9350]  ? kmsan_get_metadata+0x13e/0x1c0
set ...
[   70.221254][ T9350]  ? __msan_warning+0x96/0x120
[   70.222066][ T9350]  ? __hfsplus_ext_cache_extent+0x7d0/0x990
[   70.223023][ T9350]  ? hfsplus_file_extend+0x74f/0x1cf0
[   70.224120][ T9350]  ? hfsplus_get_block+0xe16/0x17b0
[   70.224946][ T9350]  ? __block_write_begin_int+0x962/0x2ce0
[   70.225756][ T9350]  ? cont_write_begin+0x1000/0x1950
[   70.226337][ T9350]  ? hfsplus_write_begin+0x85/0x130
[   70.226852][ T9350]  ? generic_perform_write+0x3e8/0x1060
[   70.227405][ T9350]  ? __generic_file_write_iter+0x215/0x460
[   70.227979][ T9350]  ? generic_file_write_iter+0x109/0x5e0
[   70.228540][ T9350]  ? vfs_write+0xb0f/0x14e0
[   70.228997][ T9350]  ? ksys_write+0x23e/0x490
[   70.229458][ T9350]  ? __x64_sys_write+0x97/0xf0
[   70.229939][ T9350]  ? x64_sys_call+0x3015/0x3cf0
[   70.230432][ T9350]  ? do_syscall_64+0xd9/0x1d0
[   70.230941][ T9350]  ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.231926][ T9350]  ? kmsan_get_metadata+0x13e/0x1c0
[   70.232738][ T9350]  ? kmsan_internal_set_shadow_origin+0x77/0x110
[   70.233711][ T9350]  ? kmsan_get_metadata+0x13e/0x1c0
[   70.234516][ T9350]  ? kmsan_get_shadow_origin_ptr+0x4a/0xb0
[   70.235398][ T9350]  ? __msan_metadata_ptr_for_load_4+0x24/0x40
[   70.236323][ T9350]  ? hfsplus_brec_find+0x218/0x9f0
[   70.237090][ T9350]  ? __pfx_hfs_find_rec_by_key+0x10/0x10
[   70.237938][ T9350]  ? __msan_instrument_asm_store+0xbf/0xf0
[   70.238827][ T9350]  ? __msan_metadata_ptr_for_store_4+0x27/0x40
[   70.239772][ T9350]  ? __hfsplus_ext_write_extent+0x536/0x620
[   70.240666][ T9350]  ? kmsan_get_metadata+0x13e/0x1c0
[   70.241175][ T9350]  __msan_warning+0x96/0x120
[   70.241645][ T9350]  __hfsplus_ext_cache_extent+0x7d0/0x990
[   70.242223][ T9350]  hfsplus_file_extend+0x74f/0x1cf0
[   70.242748][ T9350]  hfsplus_get_block+0xe16/0x17b0
[   70.243255][ T9350]  ? kmsan_internal_set_shadow_origin+0x77/0x110
[   70.243878][ T9350]  ? kmsan_get_metadata+0x13e/0x1c0
[   70.244400][ T9350]  ? kmsan_get_shadow_origin_ptr+0x4a/0xb0
[   70.244967][ T9350]  __block_write_begin_int+0x962/0x2ce0
[   70.245531][ T9350]  ? __pfx_hfsplus_get_block+0x10/0x10
[   70.246079][ T9350]  cont_write_begin+0x1000/0x1950
[   70.246598][ T9350]  hfsplus_write_begin+0x85/0x130
[   70.247105][ T9350]  ? __pfx_hfsplus_get_block+0x10/0x10
[   70.247650][ T9350]  ? __pfx_hfsplus_write_begin+0x10/0x10
[   70.248211][ T9350]  generic_perform_write+0x3e8/0x1060
[   70.248752][ T9350]  __generic_file_write_iter+0x215/0x460
[   70.249314][ T9350]  generic_file_write_iter+0x109/0x5e0
[   70.249856][ T9350]  ? kmsan_internal_set_shadow_origin+0x77/0x110
[   70.250487][ T9350]  vfs_write+0xb0f/0x14e0
[   70.250930][ T9350]  ? __pfx_generic_file_write_iter+0x10/0x10
[   70.251530][ T9350]  ksys_write+0x23e/0x490
[   70.251974][ T9350]  __x64_sys_write+0x97/0xf0
[   70.252450][ T9350]  x64_sys_call+0x3015/0x3cf0
[   70.252924][ T9350]  do_syscall_64+0xd9/0x1d0
[   70.253384][ T9350]  ? irqentry_exit+0x16/0x60
[   70.253844][ T9350]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.254430][ T9350] RIP: 0033:0x7f7a92adffc9
[   70.254873][ T9350] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 48
[   70.256674][ T9350] RSP: 002b:00007fff0bca3188 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[   70.257485][ T9350] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7a92adffc9
[   70.258246][ T9350] RDX: 000000000208e24b RSI: 0000000020000100 RDI: 0000000000000004
[   70.258998][ T9350] RBP: 00007fff0bca31a0 R08: 00007fff0bca31a0 R09: 00007fff0bca31a0
[   70.259769][ T9350] R10: 0000000000000000 R11: 0000000000000202 R12: 000055e0d75f8250
[   70.260520][ T9350] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   70.261286][ T9350]  </TASK>
[   70.262026][ T9350] Kernel Offset: disabled

(gdb) l *__hfsplus_ext_cache_extent+0x7d0
0xffffffff8318aef0 is in __hfsplus_ext_cache_extent (fs/hfsplus/extents.c:168).
163		fd->key->ext.cnid = 0;
164		res = hfs_brec_find(fd, hfs_find_rec_by_key);
165		if (res && res != -ENOENT)
166			return res;
167		if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
168		    fd->key->ext.fork_type != fd->search_key->ext.fork_type)
169			return -ENOENT;
170		if (fd->entrylength != sizeof(hfsplus_extent_rec))
171			return -EIO;
172		hfs_bnode_read(fd->bnode, extent, fd->entryoffset,

The __hfsplus_ext_cache_extent() calls __hfsplus_ext_read_extent():

res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
				block, HFSPLUS_IS_RSRC(inode) ?
					HFSPLUS_TYPE_RSRC :
					HFSPLUS_TYPE_DATA);

And if inode->i_ino could be equal to zero or any non-available CNID,
then hfs_brec_find() could not find the record in the tree. As a result,
fd->key could be compared with fd->search_key. But hfsplus_find_init()
uses kmalloc() for fd->key and fd->search_key allocation:

int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd)
{
<skipped>
        ptr = kmalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
        if (!ptr)
                return -ENOMEM;
        fd->search_key = ptr;
        fd->key = ptr + tree->max_key_len + 2;
<skipped>
}

Finally, fd->key is still not initialized if hfs_brec_find()
has found nothing.

This patch changes kmalloc() on kzalloc() in hfs_find_init()
and intializes fd->record, fd->keyoffset, fd->keylength,
fd->entryoffset, fd->entrylength for the case if hfs_brec_find()
has been found nothing in the b-tree node.

Reported-by: syzbot <syzbot+55ad87f38795d6787521@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=55ad87f38795d6787521
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
cc: Yangtao Li <frank.li@vivo.com>
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20250818225232.126402-1-slava@dubeyko.com
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/hfsplus/bfind.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/hfsplus/bfind.c b/fs/hfsplus/bfind.c
index 901e83d65d202..26ebac4c60424 100644
--- a/fs/hfsplus/bfind.c
+++ b/fs/hfsplus/bfind.c
@@ -18,7 +18,7 @@ int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd)
 
 	fd->tree = tree;
 	fd->bnode = NULL;
-	ptr = kmalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
+	ptr = kzalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
 	if (!ptr)
 		return -ENOMEM;
 	fd->search_key = ptr;
@@ -158,6 +158,12 @@ int hfs_brec_find(struct hfs_find_data *fd, search_strategy_t do_key_compare)
 	__be32 data;
 	int height, res;
 
+	fd->record = -1;
+	fd->keyoffset = -1;
+	fd->keylength = -1;
+	fd->entryoffset = -1;
+	fd->entrylength = -1;
+
 	tree = fd->tree;
 	if (fd->bnode)
 		hfs_bnode_put(fd->bnode);
-- 
2.51.0

[PATCH 5.4 177/224] hfsplus: fix KMSAN uninit-value issue in hfsplus_delete_cat()

[Greg Kroah-Hartman]

5.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Viacheslav Dubeyko <slava@dubeyko.com>

[ Upstream commit 9b3d15a758910bb98ba8feb4109d99cc67450ee4 ]

The syzbot reported issue in hfsplus_delete_cat():

[   70.682285][ T9333] =====================================================
[   70.682943][ T9333] BUG: KMSAN: uninit-value in hfsplus_subfolders_dec+0x1d7/0x220
[   70.683640][ T9333]  hfsplus_subfolders_dec+0x1d7/0x220
[   70.684141][ T9333]  hfsplus_delete_cat+0x105d/0x12b0
[   70.684621][ T9333]  hfsplus_rmdir+0x13d/0x310
[   70.685048][ T9333]  vfs_rmdir+0x5ba/0x810
[   70.685447][ T9333]  do_rmdir+0x964/0xea0
[   70.685833][ T9333]  __x64_sys_rmdir+0x71/0xb0
[   70.686260][ T9333]  x64_sys_call+0xcd8/0x3cf0
[   70.686695][ T9333]  do_syscall_64+0xd9/0x1d0
[   70.687119][ T9333]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.687646][ T9333]
[   70.687856][ T9333] Uninit was stored to memory at:
[   70.688311][ T9333]  hfsplus_subfolders_inc+0x1c2/0x1d0
[   70.688779][ T9333]  hfsplus_create_cat+0x148e/0x1800
[   70.689231][ T9333]  hfsplus_mknod+0x27f/0x600
[   70.689730][ T9333]  hfsplus_mkdir+0x5a/0x70
[   70.690146][ T9333]  vfs_mkdir+0x483/0x7a0
[   70.690545][ T9333]  do_mkdirat+0x3f2/0xd30
[   70.690944][ T9333]  __x64_sys_mkdir+0x9a/0xf0
[   70.691380][ T9333]  x64_sys_call+0x2f89/0x3cf0
[   70.691816][ T9333]  do_syscall_64+0xd9/0x1d0
[   70.692229][ T9333]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.692773][ T9333]
[   70.692990][ T9333] Uninit was stored to memory at:
[   70.693469][ T9333]  hfsplus_subfolders_inc+0x1c2/0x1d0
[   70.693960][ T9333]  hfsplus_create_cat+0x148e/0x1800
[   70.694438][ T9333]  hfsplus_fill_super+0x21c1/0x2700
[   70.694911][ T9333]  mount_bdev+0x37b/0x530
[   70.695320][ T9333]  hfsplus_mount+0x4d/0x60
[   70.695729][ T9333]  legacy_get_tree+0x113/0x2c0
[   70.696167][ T9333]  vfs_get_tree+0xb3/0x5c0
[   70.696588][ T9333]  do_new_mount+0x73e/0x1630
[   70.697013][ T9333]  path_mount+0x6e3/0x1eb0
[   70.697425][ T9333]  __se_sys_mount+0x733/0x830
[   70.697857][ T9333]  __x64_sys_mount+0xe4/0x150
[   70.698269][ T9333]  x64_sys_call+0x2691/0x3cf0
[   70.698704][ T9333]  do_syscall_64+0xd9/0x1d0
[   70.699117][ T9333]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.699730][ T9333]
[   70.699946][ T9333] Uninit was created at:
[   70.700378][ T9333]  __alloc_pages_noprof+0x714/0xe60
[   70.700843][ T9333]  alloc_pages_mpol_noprof+0x2a2/0x9b0
[   70.701331][ T9333]  alloc_pages_noprof+0xf8/0x1f0
[   70.701774][ T9333]  allocate_slab+0x30e/0x1390
[   70.702194][ T9333]  ___slab_alloc+0x1049/0x33a0
[   70.702635][ T9333]  kmem_cache_alloc_lru_noprof+0x5ce/0xb20
[   70.703153][ T9333]  hfsplus_alloc_inode+0x5a/0xd0
[   70.703598][ T9333]  alloc_inode+0x82/0x490
[   70.703984][ T9333]  iget_locked+0x22e/0x1320
[   70.704428][ T9333]  hfsplus_iget+0x5c/0xba0
[   70.704827][ T9333]  hfsplus_btree_open+0x135/0x1dd0
[   70.705291][ T9333]  hfsplus_fill_super+0x1132/0x2700
[   70.705776][ T9333]  mount_bdev+0x37b/0x530
[   70.706171][ T9333]  hfsplus_mount+0x4d/0x60
[   70.706579][ T9333]  legacy_get_tree+0x113/0x2c0
[   70.707019][ T9333]  vfs_get_tree+0xb3/0x5c0
[   70.707444][ T9333]  do_new_mount+0x73e/0x1630
[   70.707865][ T9333]  path_mount+0x6e3/0x1eb0
[   70.708270][ T9333]  __se_sys_mount+0x733/0x830
[   70.708711][ T9333]  __x64_sys_mount+0xe4/0x150
[   70.709158][ T9333]  x64_sys_call+0x2691/0x3cf0
[   70.709630][ T9333]  do_syscall_64+0xd9/0x1d0
[   70.710053][ T9333]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.710611][ T9333]
[   70.710842][ T9333] CPU: 3 UID: 0 PID: 9333 Comm: repro Not tainted 6.12.0-rc6-dirty #17
[   70.711568][ T9333] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   70.712490][ T9333] =====================================================
[   70.713085][ T9333] Disabling lock debugging due to kernel taint
[   70.713618][ T9333] Kernel panic - not syncing: kmsan.panic set ...
[   70.714159][ T9333] CPU: 3 UID: 0 PID: 9333 Comm: repro Tainted: G    B              6.12.0-rc6-dirty #17
[   70.715007][ T9333] Tainted: [B]=BAD_PAGE
[   70.715365][ T9333] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   70.716311][ T9333] Call Trace:
[   70.716621][ T9333]  <TASK>
[   70.716899][ T9333]  dump_stack_lvl+0x1fd/0x2b0
[   70.717350][ T9333]  dump_stack+0x1e/0x30
[   70.717743][ T9333]  panic+0x502/0xca0
[   70.718116][ T9333]  ? kmsan_get_metadata+0x13e/0x1c0
[   70.718611][ T9333]  kmsan_report+0x296/0x2a0
[   70.719038][ T9333]  ? __msan_metadata_ptr_for_load_4+0x24/0x40
[   70.719859][ T9333]  ? __msan_warning+0x96/0x120
[   70.720345][ T9333]  ? hfsplus_subfolders_dec+0x1d7/0x220
[   70.720881][ T9333]  ? hfsplus_delete_cat+0x105d/0x12b0
[   70.721412][ T9333]  ? hfsplus_rmdir+0x13d/0x310
[   70.721880][ T9333]  ? vfs_rmdir+0x5ba/0x810
[   70.722458][ T9333]  ? do_rmdir+0x964/0xea0
[   70.722883][ T9333]  ? __x64_sys_rmdir+0x71/0xb0
[   70.723397][ T9333]  ? x64_sys_call+0xcd8/0x3cf0
[   70.723915][ T9333]  ? do_syscall_64+0xd9/0x1d0
[   70.724454][ T9333]  ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.725110][ T9333]  ? vprintk_emit+0xd1f/0xe60
[   70.725616][ T9333]  ? vprintk_default+0x3f/0x50
[   70.726175][ T9333]  ? vprintk+0xce/0xd0
[   70.726628][ T9333]  ? _printk+0x17e/0x1b0
[   70.727129][ T9333]  ? __msan_metadata_ptr_for_load_4+0x24/0x40
[   70.727739][ T9333]  ? kmsan_get_metadata+0x13e/0x1c0
[   70.728324][ T9333]  __msan_warning+0x96/0x120
[   70.728854][ T9333]  hfsplus_subfolders_dec+0x1d7/0x220
[   70.729479][ T9333]  hfsplus_delete_cat+0x105d/0x12b0
[   70.729984][ T9333]  ? kmsan_get_shadow_origin_ptr+0x4a/0xb0
[   70.730646][ T9333]  ? __msan_metadata_ptr_for_load_4+0x24/0x40
[   70.731296][ T9333]  ? kmsan_get_metadata+0x13e/0x1c0
[   70.731863][ T9333]  hfsplus_rmdir+0x13d/0x310
[   70.732390][ T9333]  ? __pfx_hfsplus_rmdir+0x10/0x10
[   70.732919][ T9333]  vfs_rmdir+0x5ba/0x810
[   70.733416][ T9333]  ? kmsan_get_shadow_origin_ptr+0x4a/0xb0
[   70.734044][ T9333]  do_rmdir+0x964/0xea0
[   70.734537][ T9333]  __x64_sys_rmdir+0x71/0xb0
[   70.735032][ T9333]  x64_sys_call+0xcd8/0x3cf0
[   70.735579][ T9333]  do_syscall_64+0xd9/0x1d0
[   70.736092][ T9333]  ? irqentry_exit+0x16/0x60
[   70.736637][ T9333]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   70.737269][ T9333] RIP: 0033:0x7fa9424eafc9
[   70.737775][ T9333] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 48
[   70.739844][ T9333] RSP: 002b:00007fff099cd8d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000054
[   70.740760][ T9333] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa9424eafc9
[   70.741642][ T9333] RDX: 006c6f72746e6f63 RSI: 000000000000000a RDI: 0000000020000100
[   70.742543][ T9333] RBP: 00007fff099cd8e0 R08: 00007fff099cd910 R09: 00007fff099cd910
[   70.743376][ T9333] R10: 0000000000000000 R11: 0000000000000202 R12: 0000565430642260
[   70.744247][ T9333] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   70.745082][ T9333]  </TASK>

The main reason of the issue that struct hfsplus_inode_info
has not been properly initialized for the case of root folder.
In the case of root folder, hfsplus_fill_super() calls
the hfsplus_iget() that implements only partial initialization of
struct hfsplus_inode_info and subfolders field is not
initialized by hfsplus_iget() logic.

This patch implements complete initialization of
struct hfsplus_inode_info in the hfsplus_iget() logic with
the goal to prevent likewise issues for the case of
root folder.

Reported-by: syzbot <syzbot+fdedff847a0e5e84c39f@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=fdedff847a0e5e84c39f
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
cc: Yangtao Li <frank.li@vivo.com>
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20250825225103.326401-1-slava@dubeyko.com
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/hfsplus/super.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 29a39afe26535..d744fde416804 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -67,13 +67,26 @@ struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino)
 	if (!(inode->i_state & I_NEW))
 		return inode;
 
-	INIT_LIST_HEAD(&HFSPLUS_I(inode)->open_dir_list);
-	spin_lock_init(&HFSPLUS_I(inode)->open_dir_lock);
-	mutex_init(&HFSPLUS_I(inode)->extents_lock);
-	HFSPLUS_I(inode)->flags = 0;
+	atomic_set(&HFSPLUS_I(inode)->opencnt, 0);
+	HFSPLUS_I(inode)->first_blocks = 0;
+	HFSPLUS_I(inode)->clump_blocks = 0;
+	HFSPLUS_I(inode)->alloc_blocks = 0;
+	HFSPLUS_I(inode)->cached_start = U32_MAX;
+	HFSPLUS_I(inode)->cached_blocks = 0;
+	memset(HFSPLUS_I(inode)->first_extents, 0, sizeof(hfsplus_extent_rec));
+	memset(HFSPLUS_I(inode)->cached_extents, 0, sizeof(hfsplus_extent_rec));
 	HFSPLUS_I(inode)->extent_state = 0;
+	mutex_init(&HFSPLUS_I(inode)->extents_lock);
 	HFSPLUS_I(inode)->rsrc_inode = NULL;
-	atomic_set(&HFSPLUS_I(inode)->opencnt, 0);
+	HFSPLUS_I(inode)->create_date = 0;
+	HFSPLUS_I(inode)->linkid = 0;
+	HFSPLUS_I(inode)->flags = 0;
+	HFSPLUS_I(inode)->fs_blocks = 0;
+	HFSPLUS_I(inode)->userflags = 0;
+	HFSPLUS_I(inode)->subfolders = 0;
+	INIT_LIST_HEAD(&HFSPLUS_I(inode)->open_dir_list);
+	spin_lock_init(&HFSPLUS_I(inode)->open_dir_lock);
+	HFSPLUS_I(inode)->phys_size = 0;
 
 	if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID ||
 	    inode->i_ino == HFSPLUS_ROOT_CNID) {
-- 
2.51.0

[PATCH 5.4 179/224] hfs: fix KMSAN uninit-value issue in hfs_find_set_zero_bits()

[Greg Kroah-Hartman]

5.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Viacheslav Dubeyko <slava@dubeyko.com>

[ Upstream commit 2048ec5b98dbdfe0b929d2e42dc7a54c389c53dd ]

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.

Reported-by: syzbot <syzbot+773fa9d79b29bd8b6831@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=773fa9d79b29bd8b6831
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
cc: Yangtao Li <frank.li@vivo.com>
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20250820230636.179085-1-slava@dubeyko.com
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/hfs/mdb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/hfs/mdb.c b/fs/hfs/mdb.c
index 460281b1299eb..8036445672c5f 100644
--- a/fs/hfs/mdb.c
+++ b/fs/hfs/mdb.c
@@ -166,7 +166,7 @@ int hfs_mdb_get(struct super_block *sb)
 		pr_warn("continuing without an alternate MDB\n");
 	}
 
-	HFS_SB(sb)->bitmap = kmalloc(8192, GFP_KERNEL);
+	HFS_SB(sb)->bitmap = kzalloc(8192, GFP_KERNEL);
 	if (!HFS_SB(sb)->bitmap)
 		goto out;
 
-- 
2.51.0