[v6.1] WARNING in __kernel_write_iter

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 7eaef76fbc46 Linux 6.1.20
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=169bc181c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=29ad3fe3c7b61175
dashboard link: https://syzkaller.appspot.com/bug?extid=78d9dc0d718d214e0bf2
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/34f95428f5fb/disk-7eaef76f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1bdd9b2c390d/vmlinux-7eaef76f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/419140981cfa/Image-7eaef76f.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+78d9dc...@syzkaller.appspotmail.com

BTRFS info (device loop2): using sha256 (sha256-ce) checksum algorithm
BTRFS info (device loop2): using free space tree
BTRFS info (device loop2): enabling ssd optimizations
------------[ cut here ]------------
WARNING: CPU: 1 PID: 24305 at fs/read_write.c:504 __kernel_write_iter+0x508/0x5f8
Modules linked in:
CPU: 1 PID: 24305 Comm: syz-executor.2 Not tainted 6.1.20-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __kernel_write_iter+0x508/0x5f8
lr : __kernel_write_iter+0x504/0x5f8 fs/read_write.c:504
sp : ffff800020f474c0
x29: ffff800020f475a0 x28: ffff7000041e8ea0 x27: ffff800020f47640
x26: dfff800000000000 x25: fffffffffffffff7 x24: 1fffe00026f81def
x23: ffff000137c0ef7c x22: ffff00011cc6bc08 x21: dfff800000000000
x20: ffff000137c0ef00 x19: 00000000000a8019 x18: ffff800020f47560
x17: 0000000000000000 x16: ffff8000121a8c80 x15: 0000000000046a13
x14: 1ffff00002ae60b0 x13: dfff800000000000 x12: 0000000000040000
x11: 00000000000030fa x10: ffff800025e1c000 x9 : ffff800008a4398c
x8 : 00000000000030fb x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000011 x3 : 0000000000000001
x2 : ffff00011cc6bc08 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
__kernel_write_iter+0x508/0x5f8
__kernel_write fs/read_write.c:537 [inline]
kernel_write+0x1b0/0x2f0 fs/read_write.c:558
write_buf fs/btrfs/send.c:591 [inline]
send_header fs/btrfs/send.c:709 [inline]
send_subvol+0x174/0x3f0c fs/btrfs/send.c:7675
btrfs_ioctl_send+0x1c40/0x21b4 fs/btrfs/send.c:8041
_btrfs_ioctl_send+0x314/0x468 fs/btrfs/ioctl.c:5233
btrfs_ioctl+0x638/0xb08
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+0x14c/0x1c8 fs/ioctl.c:856
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581
irq event stamp: 83208
hardirqs last enabled at (83207): [<ffff80000896fe60>] ___slab_alloc+0xd08/0xee0 mm/slub.c:3132
hardirqs last disabled at (83208): [<ffff8000122560d4>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (83172): [<ffff8000080337c4>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (83170): [<ffff800008033790>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: ca48fc16c493 Linux 6.1.27
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=163e4304280000
kernel config: https://syzkaller.appspot.com/x/.config?x=aea4bb7802570997

dashboard link: https://syzkaller.appspot.com/bug?extid=78d9dc0d718d214e0bf2
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13455122280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10edaaa8280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ec11c1903c52/disk-ca48fc16.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8ce41c1ad391/vmlinux-ca48fc16.xz
kernel image: https://storage.googleapis.com/syzbot-assets/affba5631cad/Image-ca48fc16.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/2930620842cb/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+78d9dc...@syzkaller.appspotmail.com

BTRFS info (device loop0): using sha256 (sha256-ce) checksum algorithm
BTRFS info (device loop0): using free space tree
BTRFS info (device loop0): enabling ssd optimizations
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4218 at fs/read_write.c:504 __kernel_write_iter+0x508/0x5f8
Modules linked in:
CPU: 0 PID: 4218 Comm: syz-executor165 Not tainted 6.1.27-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023

pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __kernel_write_iter+0x508/0x5f8
lr : __kernel_write_iter+0x504/0x5f8 fs/read_write.c:504

sp : ffff80001da274c0
x29: ffff80001da275a0 x28: ffff700003b44ea0 x27: ffff80001da27640
x26: dfff800000000000 x25: fffffffffffffff7 x24: 1fffe0001b2abd9f
x23: ffff0000d955ecfc x22: ffff0000d5afbc08 x21: dfff800000000000
x20: ffff0000d955ec80 x19: 00000000000a001d x18: ffff80001da27560
x17: ffff80000a1b0f58 x16: ffff800012034640 x15: 000000000000c12e
x14: 1ffff00002ab20b0 x13: dfff800000000000 x12: 0000000000000005
x11: ff80800008a31c38 x10: 0000000000000000 x9 : ffff800008a31c38
x8 : ffff0000d4b09b40 x7 : 0000000000000000 x6 : 0000000000000000

x5 : 0000000000000000 x4 : 0000000000000011 x3 : 0000000000000001

x2 : ffff0000d5afbc08 x1 : 0000000000000000 x0 : 0000000000000000

Call trace:
__kernel_write_iter+0x508/0x5f8
__kernel_write fs/read_write.c:537 [inline]
kernel_write+0x1b0/0x2f0 fs/read_write.c:558
write_buf fs/btrfs/send.c:591 [inline]
send_header fs/btrfs/send.c:709 [inline]
send_subvol+0x174/0x3f0c fs/btrfs/send.c:7675
btrfs_ioctl_send+0x1c40/0x21b4 fs/btrfs/send.c:8041

_btrfs_ioctl_send+0x314/0x468 fs/btrfs/ioctl.c:5235

btrfs_ioctl+0x638/0xb08
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+0x14c/0x1c8 fs/ioctl.c:856
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

irq event stamp: 88290
hardirqs last enabled at (88289): [<ffff8000121c463c>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last enabled at (88289): [<ffff8000121c463c>] _raw_spin_unlock_irqrestore+0x48/0xac kernel/locking/spinlock.c:194
hardirqs last disabled at (88290): [<ffff8000120e200c>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (88192): [<ffff800008032b74>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (88190): [<ffff800008032b40>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19

---[ end trace 0000000000000000 ]---


---

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]

syzbot suspects this issue was fixed by commit:

commit 4fc9c61c02c0a59d2f273933c32776d403202c09
Author: Jann Horn <ja...@google.com>
Date: Fri Nov 24 16:48:31 2023 +0000

btrfs: send: ensure send_fd is writable

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13914829e80000
start commit: 76ba310227d2 Linux 6.1.32
git tree: linux-6.1.y
kernel config: https://syzkaller.appspot.com/x/.config?x=662f56cd322cfd0e
dashboard link: https://syzkaller.appspot.com/bug?extid=78d9dc0d718d214e0bf2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1243961d280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16e165a3280000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: btrfs: send: ensure send_fd is writable

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