[syzbot] [ntfs3?] KMSAN: uninit-value in ntfs_read_bh

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 431c1646e1f8 Linux 6.11-rc6
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=137426eb980000
kernel config: https://syzkaller.appspot.com/x/.config?x=35c699864e165c51
dashboard link: https://syzkaller.appspot.com/bug?extid=7a2ba6b7b66340cff225
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5ab3219cb5e8/disk-431c1646.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/82e6779c1851/vmlinux-431c1646.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d5d4a104ce36/bzImage-431c1646.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7a2ba6...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in ntfs_fix_post_read fs/ntfs3/fsntfs.c:180 [inline]
BUG: KMSAN: uninit-value in ntfs_read_bh+0x1eb/0xde0 fs/ntfs3/fsntfs.c:1317
ntfs_fix_post_read fs/ntfs3/fsntfs.c:180 [inline]
ntfs_read_bh+0x1eb/0xde0 fs/ntfs3/fsntfs.c:1317
indx_read+0x44e/0x17b0 fs/ntfs3/index.c:1067
indx_find+0xd12/0x1440 fs/ntfs3/index.c:1181
indx_update_dup+0x607/0xf80 fs/ntfs3/index.c:2666
ni_update_parent+0x12de/0x14b0 fs/ntfs3/frecord.c:3301
ni_write_inode+0x1cf4/0x1de0 fs/ntfs3/frecord.c:3392
ntfs3_write_inode+0x94/0xb0 fs/ntfs3/inode.c:1052
write_inode fs/fs-writeback.c:1497 [inline]
__writeback_single_inode+0x849/0x12c0 fs/fs-writeback.c:1716
writeback_sb_inodes+0xc95/0x1e00 fs/fs-writeback.c:1947
wb_writeback+0x4df/0xea0 fs/fs-writeback.c:2127
wb_do_writeback fs/fs-writeback.c:2274 [inline]
wb_workfn+0x40b/0x1940 fs/fs-writeback.c:2314
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3312
worker_thread+0xea7/0x14d0 kernel/workqueue.c:3389
kthread+0x3e2/0x540 kernel/kthread.c:389
ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was stored to memory at:
ntfs_read_run_nb+0x786/0x1070 fs/ntfs3/fsntfs.c:1252
ntfs_read_bh+0x64/0xde0 fs/ntfs3/fsntfs.c:1313
indx_read+0x44e/0x17b0 fs/ntfs3/index.c:1067
indx_find+0xd12/0x1440 fs/ntfs3/index.c:1181
indx_update_dup+0x607/0xf80 fs/ntfs3/index.c:2666
ni_update_parent+0x12de/0x14b0 fs/ntfs3/frecord.c:3301
ni_write_inode+0x1cf4/0x1de0 fs/ntfs3/frecord.c:3392
ntfs3_write_inode+0x94/0xb0 fs/ntfs3/inode.c:1052
write_inode fs/fs-writeback.c:1497 [inline]
__writeback_single_inode+0x849/0x12c0 fs/fs-writeback.c:1716
writeback_sb_inodes+0xc95/0x1e00 fs/fs-writeback.c:1947
wb_writeback+0x4df/0xea0 fs/fs-writeback.c:2127
wb_do_writeback fs/fs-writeback.c:2274 [inline]
wb_workfn+0x40b/0x1940 fs/fs-writeback.c:2314
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3312
worker_thread+0xea7/0x14d0 kernel/workqueue.c:3389
kthread+0x3e2/0x540 kernel/kthread.c:389
ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was created at:
__alloc_pages_noprof+0x9d6/0xe70 mm/page_alloc.c:4718
alloc_pages_mpol_noprof+0x299/0x990 mm/mempolicy.c:2263
alloc_pages_noprof mm/mempolicy.c:2343 [inline]
folio_alloc_noprof+0x1db/0x310 mm/mempolicy.c:2350
filemap_alloc_folio_noprof+0xa6/0x440 mm/filemap.c:1008
__filemap_get_folio+0xa05/0x14b0 mm/filemap.c:1950
grow_dev_folio fs/buffer.c:1047 [inline]
grow_buffers fs/buffer.c:1113 [inline]
__getblk_slow fs/buffer.c:1139 [inline]
bdev_getblk+0x2c9/0xab0 fs/buffer.c:1441
__getblk include/linux/buffer_head.h:381 [inline]
sb_getblk include/linux/buffer_head.h:387 [inline]
ntfs_get_bh+0x605/0x1190 fs/ntfs3/fsntfs.c:1365
indx_new+0x1bc/0x780 fs/ntfs3/index.c:955
indx_insert_into_root+0x2fd1/0x37d0 fs/ntfs3/index.c:1723
indx_insert_entry+0xe1d/0xee0 fs/ntfs3/index.c:1982
ntfs_create_inode+0x4391/0x4df0 fs/ntfs3/inode.c:1689
ntfs_mkdir+0x56/0x70 fs/ntfs3/namei.c:207
vfs_mkdir+0x4a0/0x780 fs/namei.c:4210
do_mkdirat+0x529/0x810 fs/namei.c:4233
__do_sys_mkdirat fs/namei.c:4248 [inline]
__se_sys_mkdirat fs/namei.c:4246 [inline]
__x64_sys_mkdirat+0xc6/0x120 fs/namei.c:4246
x64_sys_call+0x3a81/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:259
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 2918 Comm: kworker/u8:9 Not tainted 6.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: writeback wb_workfn (flush-7:4)
=====================================================


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 88fac17500f4 Merge tag 'fuse-fixes-6.11-rc7' of git://git...
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=16802d63980000

kernel config: https://syzkaller.appspot.com/x/.config?x=35c699864e165c51
dashboard link: https://syzkaller.appspot.com/bug?extid=7a2ba6b7b66340cff225
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=168f8f0b980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1466d5b7980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6e5a9ba13ba0/disk-88fac175.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/229238ec073e/vmlinux-88fac175.xz
kernel image: https://storage.googleapis.com/syzbot-assets/64327bdcda24/bzImage-88fac175.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/b6db4a705ad8/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7a2ba6...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in ntfs_fix_post_read fs/ntfs3/fsntfs.c:180 [inline]
BUG: KMSAN: uninit-value in ntfs_read_bh+0x1eb/0xde0 fs/ntfs3/fsntfs.c:1317
ntfs_fix_post_read fs/ntfs3/fsntfs.c:180 [inline]
ntfs_read_bh+0x1eb/0xde0 fs/ntfs3/fsntfs.c:1317
indx_read+0x44e/0x17b0 fs/ntfs3/index.c:1067
indx_find+0xd12/0x1440 fs/ntfs3/index.c:1181
indx_update_dup+0x607/0xf80 fs/ntfs3/index.c:2666
ni_update_parent+0x12de/0x14b0 fs/ntfs3/frecord.c:3301
ni_write_inode+0x1cf4/0x1de0 fs/ntfs3/frecord.c:3392
ntfs3_write_inode+0x94/0xb0 fs/ntfs3/inode.c:1052
write_inode fs/fs-writeback.c:1497 [inline]
__writeback_single_inode+0x849/0x12c0 fs/fs-writeback.c:1716
writeback_sb_inodes+0xc95/0x1e00 fs/fs-writeback.c:1947

__writeback_inodes_wb+0x14c/0x440 fs/fs-writeback.c:2018
wb_writeback+0x50b/0xea0 fs/fs-writeback.c:2129
wb_check_background_flush fs/fs-writeback.c:2199 [inline]
wb_do_writeback fs/fs-writeback.c:2287 [inline]
wb_workfn+0x122c/0x1940 fs/fs-writeback.c:2314

process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3312
worker_thread+0xea7/0x14d0 kernel/workqueue.c:3389
kthread+0x3e2/0x540 kernel/kthread.c:389
ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was stored to memory at:
ntfs_read_run_nb+0x786/0x1070 fs/ntfs3/fsntfs.c:1252
ntfs_read_bh+0x64/0xde0 fs/ntfs3/fsntfs.c:1313
indx_read+0x44e/0x17b0 fs/ntfs3/index.c:1067
indx_find+0xd12/0x1440 fs/ntfs3/index.c:1181
indx_update_dup+0x607/0xf80 fs/ntfs3/index.c:2666
ni_update_parent+0x12de/0x14b0 fs/ntfs3/frecord.c:3301
ni_write_inode+0x1cf4/0x1de0 fs/ntfs3/frecord.c:3392
ntfs3_write_inode+0x94/0xb0 fs/ntfs3/inode.c:1052
write_inode fs/fs-writeback.c:1497 [inline]
__writeback_single_inode+0x849/0x12c0 fs/fs-writeback.c:1716
writeback_sb_inodes+0xc95/0x1e00 fs/fs-writeback.c:1947

__writeback_inodes_wb+0x14c/0x440 fs/fs-writeback.c:2018
wb_writeback+0x50b/0xea0 fs/fs-writeback.c:2129
wb_check_background_flush fs/fs-writeback.c:2199 [inline]
wb_do_writeback fs/fs-writeback.c:2287 [inline]
wb_workfn+0x122c/0x1940 fs/fs-writeback.c:2314

CPU: 0 UID: 0 PID: 3708 Comm: kworker/u8:20 Not tainted 6.11.0-rc6-syzkaller-00026-g88fac17500f4 #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024

Workqueue: writeback wb_workfn (flush-7:0)
=====================================================


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject: possible fix (linux-ntfs3)
Author: almaz.ale...@paragon-software.com

Not sure about all indexes on volume must have the same index_block_size.

#syz test: https://github.com/Paragon-Software-Group/linux-ntfs3.git master

diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c
index 9089c58a005c..63fbb8ba6e1b 100644
--- a/fs/ntfs3/index.c
+++ b/fs/ntfs3/index.c
@@ -892,7 +892,9 @@ int indx_init(struct ntfs_index *indx, struct ntfs_sb_info *sbi,
indx->idx2vbn_bits = __ffs(root->index_block_clst);

t32 = le32_to_cpu(root->index_block_size);
- indx->index_bits = blksize_bits(t32);
+ if (t32 != sbi->index_size)
+ goto out;
+ indx->index_bits = sbi->index_bits;

/* Check index record size. */
if (t32 < sbi->cluster_size) {
diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index 3dd6215316e4..73d72fa8ab65 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -222,8 +222,9 @@ struct ntfs_sb_info {
u32 record_size;
u32 index_size;

- u8 cluster_bits;
- u8 record_bits;
+ u8 cluster_bits; // log2(cluster_size)
+ u8 record_bits; // log2(record_size)
+ u8 index_bits; // log2(index_size)

u64 maxbytes; // Maximum size for normal files.
u64 maxbytes_sparse; // Maximum size for sparse file.
diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index 128d49512f5d..f96641b80869 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -993,6 +993,7 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,
sbi->index_size);
goto out;
}
+ sbi->index_bits = blksize_bits(sbi->index_size);

sbi->volume.size = sectors * boot_sector_size;

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KMSAN: uninit-value in ntfs_read_bh

=====================================================
BUG: KMSAN: uninit-value in ntfs_fix_post_read fs/ntfs3/fsntfs.c:180 [inline]
BUG: KMSAN: uninit-value in ntfs_read_bh+0x1eb/0xde0 fs/ntfs3/fsntfs.c:1317
ntfs_fix_post_read fs/ntfs3/fsntfs.c:180 [inline]
ntfs_read_bh+0x1eb/0xde0 fs/ntfs3/fsntfs.c:1317

indx_read+0x44e/0x17b0 fs/ntfs3/index.c:1069
indx_find+0xd12/0x1440 fs/ntfs3/index.c:1183
indx_update_dup+0x607/0xf80 fs/ntfs3/index.c:2668
ni_update_parent+0x12de/0x14b0 fs/ntfs3/frecord.c:3296
ni_write_inode+0x1cf4/0x1de0 fs/ntfs3/frecord.c:3387
ntfs3_write_inode+0x94/0xb0 fs/ntfs3/inode.c:1057

write_inode fs/fs-writeback.c:1497 [inline]
__writeback_single_inode+0x849/0x12c0 fs/fs-writeback.c:1716
writeback_sb_inodes+0xc95/0x1e00 fs/fs-writeback.c:1947

wb_writeback+0x4df/0xea0 fs/fs-writeback.c:2127
wb_do_writeback fs/fs-writeback.c:2274 [inline]

wb_workfn+0x40b/0x1940 fs/fs-writeback.c:2314

process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3312

worker_thread+0xea5/0x1520 kernel/workqueue.c:3390

kthread+0x3e2/0x540 kernel/kthread.c:389
ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was stored to memory at:
ntfs_read_run_nb+0x786/0x1070 fs/ntfs3/fsntfs.c:1252
ntfs_read_bh+0x64/0xde0 fs/ntfs3/fsntfs.c:1313

indx_read+0x44e/0x17b0 fs/ntfs3/index.c:1069
indx_find+0xd12/0x1440 fs/ntfs3/index.c:1183
indx_update_dup+0x607/0xf80 fs/ntfs3/index.c:2668
ni_update_parent+0x12de/0x14b0 fs/ntfs3/frecord.c:3296
ni_write_inode+0x1cf4/0x1de0 fs/ntfs3/frecord.c:3387
ntfs3_write_inode+0x94/0xb0 fs/ntfs3/inode.c:1057

write_inode fs/fs-writeback.c:1497 [inline]
__writeback_single_inode+0x849/0x12c0 fs/fs-writeback.c:1716
writeback_sb_inodes+0xc95/0x1e00 fs/fs-writeback.c:1947

wb_writeback+0x4df/0xea0 fs/fs-writeback.c:2127
wb_do_writeback fs/fs-writeback.c:2274 [inline]

wb_workfn+0x40b/0x1940 fs/fs-writeback.c:2314

process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3312

worker_thread+0xea5/0x1520 kernel/workqueue.c:3390

kthread+0x3e2/0x540 kernel/kthread.c:389
ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was created at:

__alloc_pages_noprof+0x9d6/0xe70 mm/page_alloc.c:4723

alloc_pages_mpol_noprof+0x299/0x990 mm/mempolicy.c:2263
alloc_pages_noprof mm/mempolicy.c:2343 [inline]
folio_alloc_noprof+0x1db/0x310 mm/mempolicy.c:2350
filemap_alloc_folio_noprof+0xa6/0x440 mm/filemap.c:1008
__filemap_get_folio+0xa05/0x14b0 mm/filemap.c:1950
grow_dev_folio fs/buffer.c:1047 [inline]
grow_buffers fs/buffer.c:1113 [inline]
__getblk_slow fs/buffer.c:1139 [inline]
bdev_getblk+0x2c9/0xab0 fs/buffer.c:1441
__getblk include/linux/buffer_head.h:381 [inline]
sb_getblk include/linux/buffer_head.h:387 [inline]
ntfs_get_bh+0x605/0x1190 fs/ntfs3/fsntfs.c:1365

indx_new+0x1bc/0x780 fs/ntfs3/index.c:957
indx_insert_into_root+0x2fd1/0x37d0 fs/ntfs3/index.c:1725
indx_insert_entry+0xe1d/0xee0 fs/ntfs3/index.c:1984
ntfs_create_inode+0x4391/0x4df0 fs/ntfs3/inode.c:1694

ntfs_mkdir+0x56/0x70 fs/ntfs3/namei.c:207
vfs_mkdir+0x4a0/0x780 fs/namei.c:4210
do_mkdirat+0x529/0x810 fs/namei.c:4233
__do_sys_mkdirat fs/namei.c:4248 [inline]
__se_sys_mkdirat fs/namei.c:4246 [inline]
__x64_sys_mkdirat+0xc6/0x120 fs/namei.c:4246

x64_sys_call+0x39e5/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:259

do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 3128 Comm: kworker/u8:10 Not tainted 6.11.0-rc1-syzkaller-00017-g689ecd06ef8d-dirty #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: writeback wb_workfn (flush-7:0)
=====================================================

Tested on:

commit: 689ecd06 fs/ntfs3: Rename ntfs3_setattr into ntfs_seta..
git tree: https://github.com/Paragon-Software-Group/linux-ntfs3.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=1626f43b980000
kernel config: https://syzkaller.appspot.com/x/.config?x=2dda45ca15df5ccb

dashboard link: https://syzkaller.appspot.com/bug?extid=7a2ba6b7b66340cff225
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=163af43b980000