syzbot <[email protected]> writes:
> Hello, > > syzbot found the following issue on: > > HEAD commit: a4cda136f021 Add linux-next specific files for 20250404 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=12c3db4c580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=8a257c454bb1afb7 > dashboard link: https://syzkaller.appspot.com/bug?extid=aec9606169fbc3a12ca6 > 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=17ca0c04580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11c3db4c580000 > > Downloadable assets: > disk image: > https://storage.googleapis.com/syzbot-assets/59048bc9c206/disk-a4cda136.raw.xz > vmlinux: > https://storage.googleapis.com/syzbot-assets/ad2ba7306f20/vmlinux-a4cda136.xz > kernel image: > https://storage.googleapis.com/syzbot-assets/b3bef7acbf10/bzImage-a4cda136.xz > mounted in repro: > https://storage.googleapis.com/syzbot-assets/110624be1513/mount_0.gz > > The issue was bisected to: > > commit dcffc3b1ae3251d796a25c673f614e3099ca83d3 > Author: Kent Overstreet <[email protected]> > Date: Sun Mar 30 03:11:08 2025 +0000 > > bcachefs: Split up bch_dev.io_ref > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13948c04580000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=10548c04580000 > console output: https://syzkaller.appspot.com/x/log.txt?x=17948c04580000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: [email protected] > Fixes: dcffc3b1ae32 ("bcachefs: Split up bch_dev.io_ref") > > bcachefs (loop0): shutting down > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 5844 at fs/bcachefs/super.c:1229 > bch2_dev_free+0x228/0x290 fs/bcachefs/super.c:1229 > Modules linked in: > CPU: 0 UID: 0 PID: 5844 Comm: syz-executor121 Not tainted > 6.14.0-next-20250404-syzkaller #0 PREEMPT(full) > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 02/12/2025 > RIP: 0010:bch2_dev_free+0x228/0x290 fs/bcachefs/super.c:1229 > Code: ff e8 4c cf 74 00 4c 89 ef e8 44 cf 74 00 48 89 df 48 83 c4 10 5b 41 5c > 41 5d 41 5e 41 5f 5d e9 ee 53 96 07 e8 59 e9 32 fd 90 <0f> 0b 90 e9 09 fe ff > ff e8 4b e9 32 fd 90 0f 0b 90 e9 15 fe ff ff > RSP: 0018:ffffc9000406fb88 EFLAGS: 00010293 > RAX: ffffffff849073d7 RBX: ffff888035282000 RCX: ffff888034af9e00 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffff8880352820c0 R08: ffffffff850552f7 R09: 0000000000000000 > R10: ffff888035282208 R11: ffffed1006a5044a R12: ffff888075e003f0 > R13: ffff8880352820b0 R14: ffff888075e00000 R15: ffff888075e007b2 > FS: 000055558bb20380(0000) GS:ffff888124f8f000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000000000045bdd0 CR3: 00000000122a0000 CR4: 00000000003526f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > bch2_fs_free+0x2b0/0x400 fs/bcachefs/super.c:688 > deactivate_locked_super+0xc4/0x130 fs/super.c:473 > cleanup_mnt+0x422/0x4c0 fs/namespace.c:1435 > task_work_run+0x251/0x310 kernel/task_work.c:227 > ptrace_notify+0x2dc/0x390 kernel/signal.c:2520 > ptrace_report_syscall include/linux/ptrace.h:415 [inline] > ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline] > syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173 > syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline] > __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] > syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218 > do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f49b0cec447 > Code: 07 00 48 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f > 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 > 01 c3 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 > RSP: 002b:00007ffd94723978 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f49b0cec447 > RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd94723a30 > RBP: 00007ffd94723a30 R08: 0000000000000000 R09: 0000000000000000 > R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffd94724aa0 > R13: 000055558bb216c0 R14: 0000000000000001 R15: 431bde82d7b634db > </TASK> > > > --- #syz test From: Charalampos Mitrodimas <[email protected]> Subject: [PATCH] bcachefs: Fix WARN_ON in bch2_dev_free After splitting bch_dev.io_ref into separate READ and WRITE refs, we need to ensure both refs are properly stopped before freeing a device. Add bch2_dev_io_ref_stop(ca, WRITE) to bch2_fs_free() to prevent the WARNING in bch2_dev_free(). Reported-by: [email protected] Fixes: dcffc3b1ae32 ("bcachefs: Split up bch_dev.io_ref") Signed-off-by: Charalampos Mitrodimas <[email protected]> --- fs/bcachefs/super.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c index a58edde43bee..089b69b685d9 100644 --- a/fs/bcachefs/super.c +++ b/fs/bcachefs/super.c @@ -684,6 +684,7 @@ void bch2_fs_free(struct bch_fs *c) if (ca) { EBUG_ON(atomic_long_read(&ca->ref) != 1); bch2_dev_io_ref_stop(ca, READ); + bch2_dev_io_ref_stop(ca, WRITE); bch2_free_super(&ca->disk_sb); bch2_dev_free(ca); } -- 2.39.5
