[syzbot] [ntfs3?] WARNING: kmalloc bug in ntfs_load_attr_list

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9a6b294ab496 afs: Fix use-after-free due to get/remove rac..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12c1ee79e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=e5751b3a2226135d
dashboard link: https://syzkaller.appspot.com/bug?extid=f987ceaddc6bcc334cde
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=1186ce6ee80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15a4c431e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/de41d893a2be/disk-9a6b294a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/96edd77e193d/vmlinux-9a6b294a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1dc01d20de05/bzImage-9a6b294a.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/1a8ca9d17233/mount_0.gz

The issue was bisected to:

commit fc471e39e38fea6677017cbdd6d928088a59fc67
Author: Konstantin Komarov <almaz.ale...@paragon-software.com>
Date: Fri Jun 30 12:12:58 2023 +0000

fs/ntfs3: Use kvmalloc instead of kmalloc(... __GFP_NOWARN)

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=150ef3e9e80000
final oops: https://syzkaller.appspot.com/x/report.txt?x=170ef3e9e80000
console output: https://syzkaller.appspot.com/x/log.txt?x=130ef3e9e80000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f987ce...@syzkaller.appspotmail.com
Fixes: fc471e39e38f ("fs/ntfs3: Use kvmalloc instead of kmalloc(... __GFP_NOWARN)")

loop0: detected capacity change from 0 to 4096
ntfs3: loop0: Different NTFS sector size (4096) and media sector size (512).
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5058 at mm/util.c:632 kvmalloc_node+0x176/0x180 mm/util.c:632
Modules linked in:
CPU: 1 PID: 5058 Comm: syz-executor408 Not tainted 6.7.0-rc6-syzkaller-00168-g9a6b294ab496 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:kvmalloc_node+0x176/0x180 mm/util.c:632
Code: c3 44 89 fe 81 e6 00 20 00 00 31 ff e8 e3 d4 c1 ff 41 81 e7 00 20 00 00 74 0a e8 25 d1 c1 ff e9 3f ff ff ff e8 1b d1 c1 ff 90 <0f> 0b 90 e9 31 ff ff ff 66 90 f3 0f 1e fa 41 56 53 49 89 f6 48 89
RSP: 0018:ffffc90003c67588 EFLAGS: 00010293
RAX: ffffffff81cc9945 RBX: 0000000100000000 RCX: ffff8880246a1dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff81cc992d R09: 00000000ffffffff
R10: ffffc90003c67420 R11: fffff5200078ce89 R12: ffff888075aa1620
R13: ffff88807c8fc0a8 R14: 00000000ffffffff R15: 0000000000000000
FS: 000055555591b380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdedfd4000 CR3: 000000001c753000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
kvmalloc include/linux/slab.h:738 [inline]
ntfs_load_attr_list+0x123/0x510 fs/ntfs3/attrlist.c:56
ntfs_read_mft fs/ntfs3/inode.c:190 [inline]
ntfs_iget5+0x10ad/0x3b70 fs/ntfs3/inode.c:534
ntfs_loadlog_and_replay+0x17d/0x530 fs/ntfs3/fsntfs.c:297
ntfs_fill_super+0x2cf1/0x4c60 fs/ntfs3/super.c:1268
get_tree_bdev+0x416/0x5b0 fs/super.c:1598
vfs_get_tree+0x8c/0x2a0 fs/super.c:1771
do_new_mount+0x28f/0xae0 fs/namespace.c:3337
do_mount fs/namespace.c:3677 [inline]
__do_sys_mount fs/namespace.c:3886 [inline]
__se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3863
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x45/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f32f0f78d4a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdedfd3188 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffdedfd3190 RCX: 00007f32f0f78d4a
RDX: 0000000020000040 RSI: 00000000200000c0 RDI: 00007ffdedfd3190
RBP: 0000000000000004 R08: 00007ffdedfd31d0 R09: 000000000001f238
R10: 0000000000000005 R11: 0000000000000286 R12: 00007ffdedfd31d0
R13: 0000000000000003 R14: 0000000000200000 R15: 0000000000000001
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

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.

If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[Edward Adam Davis]

please test WARNING: kmalloc bug in ntfs_load_attr_list

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 9a6b294ab496

diff --git a/fs/ntfs3/attrlist.c b/fs/ntfs3/attrlist.c
index 7c01735d1219..e631ecc1b9df 100644
--- a/fs/ntfs3/attrlist.c
+++ b/fs/ntfs3/attrlist.c
@@ -53,7 +53,7 @@ int ntfs_load_attr_list(struct ntfs_inode *ni, struct ATTRIB *attr)
if (!attr->non_res) {
lsize = le32_to_cpu(attr->res.data_size);
/* attr is resident: lsize < record_size (1K or 4K) */
- le = kvmalloc(al_aligned(lsize), GFP_KERNEL);
+ le = kvmalloc(al_aligned(lsize), GFP_KERNEL | __GFP_NOWARN);
if (!le) {
err = -ENOMEM;
goto out;
@@ -91,7 +91,7 @@ int ntfs_load_attr_list(struct ntfs_inode *ni, struct ATTRIB *attr)
* the result is 16M bytes per attribute list.
* Use kvmalloc to allocate in range [several Kbytes - dozen Mbytes]
*/
- le = kvmalloc(al_aligned(lsize), GFP_KERNEL);
+ le = kvmalloc(al_aligned(lsize), GFP_KERNEL | __GFP_NOWARN);
if (!le) {
err = -ENOMEM;
goto out;
diff --git a/fs/ntfs3/bitmap.c b/fs/ntfs3/bitmap.c
index 63f14a0232f6..49e660be9a0f 100644
--- a/fs/ntfs3/bitmap.c
+++ b/fs/ntfs3/bitmap.c
@@ -660,7 +660,7 @@ int wnd_init(struct wnd_bitmap *wnd, struct super_block *sb, size_t nbits)
wnd->bits_last = wbits;

wnd->free_bits =
- kvmalloc_array(wnd->nwnd, sizeof(u16), GFP_KERNEL | __GFP_ZERO);
+ kvmalloc_array(wnd->nwnd, sizeof(u16), GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);

if (!wnd->free_bits)
return -ENOMEM;
diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index 9153dffde950..87778834aa9c 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -1413,7 +1413,7 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
}

bytes = inode->i_size;
- sbi->def_table = t = kvmalloc(bytes, GFP_KERNEL);
+ sbi->def_table = t = kvmalloc(bytes, GFP_KERNEL | __GFP_NOWARN);
if (!t) {
err = -ENOMEM;
goto put_inode_out;

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+f987ce...@syzkaller.appspotmail.com

Tested on:

commit: 9a6b294a afs: Fix use-after-free due to get/remove rac..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=12708809e80000

kernel config: https://syzkaller.appspot.com/x/.config?x=e5751b3a2226135d
dashboard link: https://syzkaller.appspot.com/bug?extid=f987ceaddc6bcc334cde
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=14d6b376e80000

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

[Edward Adam Davis]

kvmalloc needs to check __GFP_NOWARN, so this flag should be passed before
applying for memory.

Fixes: fc471e39e38f ("fs/ntfs3: Use kvmalloc instead of kmalloc(... __GFP_NOWARN)")

Reported-and-tested-by: syzbot+f987ce...@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <ead...@qq.com>
---
fs/ntfs3/attrlist.c | 4 ++--
fs/ntfs3/bitmap.c | 2 +-
fs/ntfs3/super.c | 2 +-
3 files changed, 4 insertions(+), 4 deletions(-)

--
2.43.0

[Tetsuo Handa]

On 2023/12/23 13:05, Edward Adam Davis wrote:
> kvmalloc needs to check __GFP_NOWARN, so this flag should be passed before
> applying for memory.
>
> Fixes: fc471e39e38f ("fs/ntfs3: Use kvmalloc instead of kmalloc(... __GFP_NOWARN)")
> Reported-and-tested-by: syzbot+f987ce...@syzkaller.appspotmail.com
> Signed-off-by: Edward Adam Davis <ead...@qq.com>

Nack. Please don't apply this patch.

See https://lkml.kernel.org/r/bca8d526-2397-4ca5...@I-love.SAKURA.ne.jp for reason.