[Syz report] kernel BUG at fs/gfs2/quota.c:1508! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 5060 Comm: syz-executor505 Not tainted 6.7.0-rc3-syzkaller-00134-g994d5c58e50e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 RIP: 0010:gfs2_quota_cleanup+0x6b5/0x6c0 fs/gfs2/quota.c:1508 Code: fe e9 cf fd ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 2d fe ff ff 4c 89 ef e8 b6 19 23 fe e9 20 fe ff ff e8 ec 11 c7 fd 90 <0f> 0b e8 84 9c 4f 07 0f 1f 40 00 66 0f 1f 00 55 41 57 41 56 41 54 RSP: 0018:ffffc9000409f9e0 EFLAGS: 00010293 RAX: ffffffff83c76854 RBX: 0000000000000002 RCX: ffff888026001dc0 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffc9000409fb00 R08: ffffffff83c762b0 R09: 1ffff1100fd38015 R10: dffffc0000000000 R11: ffffed100fd38016 R12: dffffc0000000000 R13: ffff88807e9c0828 R14: ffff888014693580 R15: ffff88807e9c0000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f16d1bd70f8 CR3: 0000000027199000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> gfs2_put_super+0x2e1/0x940 fs/gfs2/super.c:611 generic_shutdown_super+0x13a/0x2c0 fs/super.c:696 kill_block_super+0x44/0x90 fs/super.c:1667 deactivate_locked_super+0xc1/0x130 fs/super.c:484 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1256 task_work_run+0x24a/0x300 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa34/0x2750 kernel/exit.c:871 do_group_exit+0x206/0x2c0 kernel/exit.c:1021 __do_sys_exit_group kernel/exit.c:1032 [inline] __se_sys_exit_group kernel/exit.c:1030 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1030 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b ... [pid 5060] fsconfig(4, FSCONFIG_CMD_RECONFIGURE, NULL, NULL, 0) = 0 [pid 5060] exit_group(1) = ? ... [Analysis] When the task exits, it will execute cleanup_mnt() to recycle the mounted gfs2 file system, but it performs a system call fsconfig(4, FSCONFIG_CMD_RECONFIGURE, NULL, NULL, 0) before executing the task exit operation. This will execute the following kernel path to complete the setting of SDF_JOURNAL_LIVE for sd_flags: SYSCALL_DEFINE5(fsconfig, ..)-> vfs_fsconfig_locked()-> vfs_cmd_reconfigure()-> gfs2_reconfigure()-> gfs2_make_fs_rw()-> set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags); [Fix] Add SDF_NORECOVERY check in gfs2_quota_cleanup() to avoid checking SDF_JOURNAL_LIVE on the path where gfs2 is being unmounted. Reported-and-tested-by: syzbot+3b6e67ac2b646da57862@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Edward Adam Davis <eadavis@xxxxxx> --- fs/gfs2/quota.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c index 95dae7838b4e..af32dd8a72fa 100644 --- a/fs/gfs2/quota.c +++ b/fs/gfs2/quota.c @@ -1505,7 +1505,8 @@ void gfs2_quota_cleanup(struct gfs2_sbd *sdp) LIST_HEAD(dispose); int count; - BUG_ON(test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)); + BUG_ON(!test_bit(SDF_NORECOVERY, &sdp->sd_flags) && + test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)); spin_lock(&qd_lock); list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) { -- 2.43.0