2022-11-29 08:46:09

by syzbot

[permalink] [raw]
Subject: [syzbot] WARNING: kmalloc bug in btrfs_ioctl_send

Hello,

syzbot found the following issue on:

HEAD commit: 6d464646530f Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=176a733d880000
kernel config: https://syzkaller.appspot.com/x/.config?x=54b747d981acc7b7
dashboard link: https://syzkaller.appspot.com/bug?extid=4376a9a073770c173269
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=134c3d03880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13237ca1880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d75f5f77b3a3/disk-6d464646.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9382f86e4d95/vmlinux-6d464646.xz
kernel image: https://storage.googleapis.com/syzbot-assets/cf2b5f0d51dd/Image-6d464646.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/aa0da055eccb/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

BTRFS info (device loop0): using free space tree
BTRFS info (device loop0): enabling ssd optimizations
BTRFS info (device loop0): checking UUID tree
------------[ cut here ]------------
WARNING: CPU: 1 PID: 3072 at mm/util.c:596 kvmalloc_node+0x19c/0x1a4
Modules linked in:
CPU: 1 PID: 3072 Comm: syz-executor189 Not tainted 6.1.0-rc6-syzkaller-32662-g6d464646530f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kvmalloc_node+0x19c/0x1a4
lr : kvmalloc_node+0x198/0x1a4 mm/util.c:596
sp : ffff800012f13c40
x29: ffff800012f13c50 x28: ffff0000cbb01000 x27: 0000000000000000
x26: 0000000000000000 x25: ffff0000c97a8a10 x24: ffff0000c6fa6400
x23: 0000000000000000 x22: ffff8000091f72d8 x21: 000caf0ca5eccda0
x20: 00000000ffffffff x19: 0000000000000dc0 x18: 0000000000000010
x17: ffff80000c0f0b68 x16: ffff80000dbe6158 x15: ffff0000c43a1a40
x14: 0000000000000000 x13: 00000000ffffffff x12: ffff0000c43a1a40
x11: ff808000084361e8 x10: 0000000000000000 x9 : ffff8000084361e8
x8 : ffff0000c43a1a40 x7 : ffff800008578874 x6 : 0000000000000000
x5 : 00000000ffffffff x4 : 0000000000012dc0 x3 : 0010000000000000
x2 : 000caf0ca5eccda0 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
kvmalloc_node+0x19c/0x1a4
kvmalloc include/linux/slab.h:706 [inline]
kvmalloc_array include/linux/slab.h:724 [inline]
kvcalloc include/linux/slab.h:729 [inline]
btrfs_ioctl_send+0x64c/0xed0 fs/btrfs/send.c:7915
_btrfs_ioctl_send+0x188/0x218 fs/btrfs/ioctl.c:5233
btrfs_ioctl+0x5c0/0xa64
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
irq event stamp: 82706
hardirqs last enabled at (82705): [<ffff80000844b028>] mod_lruvec_page_state include/linux/vmstat.h:563 [inline]
hardirqs last enabled at (82705): [<ffff80000844b028>] __kmalloc_large_node+0x108/0x188 mm/slab_common.c:1099
hardirqs last disabled at (82706): [<ffff80000c07d8b4>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (82616): [<ffff80000801c38c>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (82614): [<ffff80000801c358>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---


---
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2022-11-29 16:01:35

by David Sterba

[permalink] [raw]
Subject: Re: [syzbot] WARNING: kmalloc bug in btrfs_ioctl_send

On Tue, Nov 29, 2022 at 12:21:41AM -0800, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 6d464646530f Merge branch 'for-next/core' into for-kernelci
> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
> console output: https://syzkaller.appspot.com/x/log.txt?x=176a733d880000
> kernel config: https://syzkaller.appspot.com/x/.config?x=54b747d981acc7b7
> dashboard link: https://syzkaller.appspot.com/bug?extid=4376a9a073770c173269
> compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
> userspace arch: arm64
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=134c3d03880000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13237ca1880000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/d75f5f77b3a3/disk-6d464646.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/9382f86e4d95/vmlinux-6d464646.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/cf2b5f0d51dd/Image-6d464646.gz.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/aa0da055eccb/mount_0.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
>
> BTRFS info (device loop0): using free space tree
> BTRFS info (device loop0): enabling ssd optimizations
> BTRFS info (device loop0): checking UUID tree
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 3072 at mm/util.c:596 kvmalloc_node+0x19c/0x1a4

594 /* Don't even allow crazy sizes */
595 if (unlikely(size > INT_MAX)) {
596 WARN_ON_ONCE(!(flags & __GFP_NOWARN));
597 return NULL;
598 }

> Modules linked in:
> CPU: 1 PID: 3072 Comm: syz-executor189 Not tainted 6.1.0-rc6-syzkaller-32662-g6d464646530f #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
> pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : kvmalloc_node+0x19c/0x1a4
> lr : kvmalloc_node+0x198/0x1a4 mm/util.c:596
> sp : ffff800012f13c40
> x29: ffff800012f13c50 x28: ffff0000cbb01000 x27: 0000000000000000
> x26: 0000000000000000 x25: ffff0000c97a8a10 x24: ffff0000c6fa6400
> x23: 0000000000000000 x22: ffff8000091f72d8 x21: 000caf0ca5eccda0
> x20: 00000000ffffffff x19: 0000000000000dc0 x18: 0000000000000010
> x17: ffff80000c0f0b68 x16: ffff80000dbe6158 x15: ffff0000c43a1a40
> x14: 0000000000000000 x13: 00000000ffffffff x12: ffff0000c43a1a40
> x11: ff808000084361e8 x10: 0000000000000000 x9 : ffff8000084361e8
> x8 : ffff0000c43a1a40 x7 : ffff800008578874 x6 : 0000000000000000
> x5 : 00000000ffffffff x4 : 0000000000012dc0 x3 : 0010000000000000
> x2 : 000caf0ca5eccda0 x1 : 0000000000000000 x0 : 0000000000000000
> Call trace:
> kvmalloc_node+0x19c/0x1a4
> kvmalloc include/linux/slab.h:706 [inline]
> kvmalloc_array include/linux/slab.h:724 [inline]
> kvcalloc include/linux/slab.h:729 [inline]
> btrfs_ioctl_send+0x64c/0xed0 fs/btrfs/send.c:7915

7915 sctx->clone_roots = kvcalloc(sizeof(*sctx->clone_roots),
7916 arg->clone_sources_count + 1,
7917 GFP_KERNEL)

So we get some insane amount of clone_sources_count

> _btrfs_ioctl_send+0x188/0x218 fs/btrfs/ioctl.c:5233
> btrfs_ioctl+0x5c0/0xa64
> vfs_ioctl fs/ioctl.c:51 [inline]

2023-01-22 11:47:00

by syzbot

[permalink] [raw]
Subject: Re: [syzbot] [btrfs?] WARNING: kmalloc bug in btrfs_ioctl_send

syzbot has bisected this issue to:

commit 7661809d493b426e979f39ab512e3adf41fbcc69
Author: Linus Torvalds <[email protected]>
Date: Wed Jul 14 16:45:49 2021 +0000

mm: don't allow oversized kvmalloc() calls

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13f2c851480000
start commit: f9ff5644bcc0 Merge tag 'hsi-for-6.2' of git://git.kernel.o..
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=100ac851480000
console output: https://syzkaller.appspot.com/x/log.txt?x=17f2c851480000
kernel config: https://syzkaller.appspot.com/x/.config?x=827916bd156c2ec6
dashboard link: https://syzkaller.appspot.com/bug?extid=4376a9a073770c173269
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1775aed7880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11cbcbd0480000

Reported-by: [email protected]
Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection