[syzbot] [hfs?] KMSAN: uninit-value in hfsplus_lookup

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 861deac3b092 Linux 6.7-rc7
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=103d9131e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=e0c7078a6b901aa3
dashboard link: https://syzkaller.appspot.com/bug?extid=91db973302e7b18c7653
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15dd9e81e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=134b9595e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0ea60ee8ed32/disk-861deac3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6d69fdc33021/vmlinux-861deac3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f0158750d452/bzImage-861deac3.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/77e776893084/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+91db97...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 1024
=====================================================
BUG: KMSAN: uninit-value in hfsplus_lookup+0x66b/0xef0 fs/hfsplus/dir.c:83
hfsplus_lookup+0x66b/0xef0 fs/hfsplus/dir.c:83
lookup_open fs/namei.c:3455 [inline]
open_last_lookups fs/namei.c:3546 [inline]
path_openat+0x27d3/0x5c70 fs/namei.c:3776
do_filp_open+0x20d/0x590 fs/namei.c:3809
do_sys_openat2+0x1bf/0x2f0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_creat fs/open.c:1528 [inline]
__se_sys_creat fs/open.c:1522 [inline]
__x64_sys_creat+0xe6/0x140 fs/open.c:1522
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was created at:
__alloc_pages+0x9a4/0xe00 mm/page_alloc.c:4591
alloc_pages_mpol+0x62b/0x9d0 mm/mempolicy.c:2133
alloc_pages+0x1be/0x1e0 mm/mempolicy.c:2204
alloc_slab_page mm/slub.c:1870 [inline]
allocate_slab mm/slub.c:2017 [inline]
new_slab+0x421/0x1570 mm/slub.c:2070
___slab_alloc+0x13db/0x33d0 mm/slub.c:3223
__slab_alloc mm/slub.c:3322 [inline]
__slab_alloc_node mm/slub.c:3375 [inline]
slab_alloc_node mm/slub.c:3468 [inline]
slab_alloc mm/slub.c:3486 [inline]
__kmem_cache_alloc_lru mm/slub.c:3493 [inline]
kmem_cache_alloc_lru+0x552/0x970 mm/slub.c:3509
alloc_inode_sb include/linux/fs.h:2937 [inline]
hfsplus_alloc_inode+0x5a/0xc0 fs/hfsplus/super.c:627
alloc_inode+0x83/0x440 fs/inode.c:261
iget_locked+0x2dd/0xe80 fs/inode.c:1316
hfsplus_iget+0x59/0xaf0 fs/hfsplus/super.c:64
hfsplus_btree_open+0x13e/0x1d00 fs/hfsplus/btree.c:150
hfsplus_fill_super+0x1113/0x26f0 fs/hfsplus/super.c:473
mount_bdev+0x3d7/0x560 fs/super.c:1650
hfsplus_mount+0x4d/0x60 fs/hfsplus/super.c:641
legacy_get_tree+0x110/0x290 fs/fs_context.c:662
vfs_get_tree+0xa5/0x520 fs/super.c:1771
do_new_mount+0x68d/0x1550 fs/namespace.c:3337
path_mount+0x73d/0x1f20 fs/namespace.c:3664
do_mount fs/namespace.c:3677 [inline]
__do_sys_mount fs/namespace.c:3886 [inline]
__se_sys_mount+0x725/0x810 fs/namespace.c:3863
__x64_sys_mount+0xe4/0x140 fs/namespace.c:3863
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 0 PID: 5008 Comm: syz-executor168 Not tainted 6.7.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
=====================================================


---
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[Edward Adam Davis]

please test uninit-value in hfsplus_lookup

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 861deac3b092

diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 1986b4f18a90..a95a6a2246a3 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -73,6 +73,7 @@ struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino)
HFSPLUS_I(inode)->flags = 0;
HFSPLUS_I(inode)->extent_state = 0;
HFSPLUS_I(inode)->rsrc_inode = NULL;
+ HFSPLUS_I(inode)->create_date = 0;
atomic_set(&HFSPLUS_I(inode)->opencnt, 0);

if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID ||

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+91db97...@syzkaller.appspotmail.com

Tested on:

commit: 861deac3 Linux 6.7-rc7
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=153ea171e80000

kernel config: https://syzkaller.appspot.com/x/.config?x=e0c7078a6b901aa3
dashboard link: https://syzkaller.appspot.com/bug?extid=91db973302e7b18c7653
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=1464c233e80000

Note: testing is done by a robot and is best-effort only.

[Edward Adam Davis]

Add created_date initialization in hfsplus_iget().

Reported-and-tested-by: syzbot+91db97...@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <ead...@qq.com>
---
fs/hfsplus/super.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 1986b4f18a90..a95a6a2246a3 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -73,6 +73,7 @@ struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino)
HFSPLUS_I(inode)->flags = 0;
HFSPLUS_I(inode)->extent_state = 0;
HFSPLUS_I(inode)->rsrc_inode = NULL;
+ HFSPLUS_I(inode)->create_date = 0;
atomic_set(&HFSPLUS_I(inode)->opencnt, 0);

if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID ||

--
2.43.0