* [PATCH] hfsplus: fix KMSAN uninit-value issue in hfsplus_delete_cat()
@ 2025-08-25 22:51 Viacheslav Dubeyko
0 siblings, 0 replies; only message in thread
From: Viacheslav Dubeyko @ 2025-08-25 22:51 UTC (permalink / raw)
To: glaubitz, linux-fsdevel, frank.li
Cc: Slava.Dubeyko, Viacheslav Dubeyko, syzbot
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
---
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 86351bdc8985..2f215d1daf6d 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -68,13 +68,26 @@ 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) {
--
2.43.0
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2025-08-25 22:51 [PATCH] hfsplus: fix KMSAN uninit-value issue in hfsplus_delete_cat() Viacheslav Dubeyko
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