From: Junxiao Bi <junxiao.bi@xxxxxxxxxx> Subject: ocfs2: fix panic on nfs server over ocfs2 The following kernel panic was captured when running nfs server over ocfs2, at that time ocfs2_test_inode_bit() was checking whether one inode locating at "blkno" 5 was valid, that is ocfs2 root inode, its "suballoc_slot" was OCFS2_INVALID_SLOT(65535) and it was allocted from //global_inode_alloc, but here it wrongly assumed that it was got from per slot inode alloctor which would cause array overflow and trigger kernel panic. [430033.469151] BUG: unable to handle kernel paging request at 0000000000001088 [430033.469367] IP: [<ffffffff816f6898>] _raw_spin_lock+0x18/0xf0 [430033.469567] PGD 1e06ba067 PUD 1e9e7d067 PMD 0 [430033.469769] Oops: 0002 [#1] SMP [430033.469975] Modules linked in: tun nfsd lockd grace nfs_acl auth_rpcgss ocfs2 xen_netback xen_blkback xen_gntalloc xen_gntdev xen_evtchn xenfs xen_privcmd ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs bnx2fc fcoe libfcoe libfc sunrpc bridge 8021q mrp garp stp llc bonding dm_round_robin scsi_dh_emc dm_multipath iTCO_wdt iTCO_vendor_support pcspkr sb_edac edac_core i2c_i801 i2c_core lpc_ich mfd_core sg ext4 jbd2 mbcache2 sd_mod ahci libahci lpfc scsi_transport_fc be2net vxlan udp_tunnel ip6_udp_tunnel mpt3sas scsi_transport_sas raid_class crc32c_intel be2iscsi bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi ipv6 cxgb3 mdio libiscsi_tcp qla4xxx iscsi_boot_sysfs libiscsi scsi_transport_iscsi dm_mirror dm_region_hash dm_log dm_mod [430033.472350] CPU: 6 PID: 24873 Comm: nfsd Not tainted 4.1.12-124.36.1.el6uek.x86_64 #2 [430033.472719] Hardware name: Huawei CH121 V3/IT11SGCA1, BIOS 3.87 02/02/2018 [430033.472910] task: ffff88005ae98000 ti: ffff88005ae94000 task.ti: ffff88005ae94000 [430033.473277] RIP: e030:[<ffffffff816f6898>] [<ffffffff816f6898>] _raw_spin_lock+0x18/0xf0 [430033.473655] RSP: e02b:ffff88005ae97908 EFLAGS: 00010206 [430033.473850] RAX: ffff88005ae98000 RBX: 0000000000001088 RCX: 0000000000000000 [430033.474205] RDX: 0000000000020000 RSI: 0000000000000009 RDI: 0000000000001088 [430033.474574] RBP: ffff88005ae97928 R08: 0000000000000000 R09: ffff880212878e00 [430033.474938] R10: 0000000000007ff0 R11: 0000000000000000 R12: 0000000000001088 [430033.475324] R13: ffff8800063c0aa8 R14: ffff8800650c27d0 R15: 000000000000ffff [430033.475721] FS: 0000000000000000(0000) GS:ffff880218180000(0000) knlGS:ffff880218180000 [430033.476199] CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033 [430033.476390] CR2: 0000000000001088 CR3: 00000002033d0000 CR4: 0000000000042660 [430033.476760] Stack: [430033.476942] 0000000000001000 0000000000001088 ffff8800063c0aa8 ffff8800650c27d0 [430033.477329] ffff88005ae97948 ffffffff8122a3de 0000000000000009 ffff8800063c0000 [430033.477718] ffff88005ae979e8 ffffffffc0714e43 ffff88005ae97968 ffff88019de8f958 [430033.478104] Call Trace: [430033.478286] [<ffffffff8122a3de>] igrab+0x1e/0x60 [430033.478494] [<ffffffffc0714e43>] ocfs2_get_system_file_inode+0x63/0x3a0 [ocfs2] [430033.478870] [<ffffffffc06a87df>] ? ocfs2_read_blocks_sync+0x13f/0x3c0 [ocfs2] [430033.479267] [<ffffffffc06ff2d8>] ocfs2_test_inode_bit+0x328/0xa00 [ocfs2] [430033.479498] [<ffffffffc06bef5a>] ocfs2_get_parent+0xba/0x3e0 [ocfs2] [430033.479730] [<ffffffff8129b305>] reconnect_path+0xb5/0x300 [430033.479933] [<ffffffff8129b646>] exportfs_decode_fh+0xf6/0x2b0 [430033.480124] [<ffffffffc0814af0>] ? nfsd_proc_getattr+0xa0/0xa0 [nfsd] [430033.480294] [<ffffffffc081a682>] ? exp_find+0xe2/0x190 [nfsd] [430033.480461] [<ffffffff810e5a7e>] ? irq_get_irq_data+0xe/0x10 [430033.480627] [<ffffffff810ea1a7>] ? __call_rcu_nocb_enqueue+0xd7/0xe0 [430033.480794] [<ffffffff810eb9e8>] ? __call_rcu+0xe8/0x360 [430033.480959] [<ffffffffc0815860>] fh_verify+0x350/0x660 [nfsd] [430033.481134] [<ffffffffc0535076>] ? cache_check+0x56/0x3a0 [sunrpc] [430033.481317] [<ffffffffc0823a4d>] nfsd4_putfh+0x4d/0x60 [nfsd] [430033.481505] [<ffffffffc0826003>] nfsd4_proc_compound+0x3d3/0x6f0 [nfsd] [430033.481730] [<ffffffffc0811f60>] nfsd_dispatch+0xe0/0x290 [nfsd] [430033.481950] [<ffffffffc052b752>] ? svc_tcp_adjust_wspace+0x12/0x30 [sunrpc] [430033.482152] [<ffffffffc052a512>] svc_process_common+0x412/0x6a0 [sunrpc] [430033.482351] [<ffffffffc052a8c3>] svc_process+0x123/0x210 [sunrpc] [430033.482550] [<ffffffffc081190f>] nfsd+0xff/0x170 [nfsd] [430033.482744] [<ffffffffc0811810>] ? nfsd_destroy+0x80/0x80 [nfsd] [430033.482943] [<ffffffff810a7aeb>] kthread+0xcb/0xf0 [430033.483151] [<ffffffff816f10ea>] ? __schedule+0x24a/0x810 [430033.483354] [<ffffffff816f10ea>] ? __schedule+0x24a/0x810 [430033.483553] [<ffffffff810a7a20>] ? kthread_create_on_node+0x180/0x180 [430033.483777] [<ffffffff816f72a1>] ret_from_fork+0x61/0x90 [430033.483976] [<ffffffff810a7a20>] ? kthread_create_on_node+0x180/0x180 [430033.484191] Code: 83 c2 02 0f b7 f2 e8 18 dc 91 ff 66 90 eb bf 0f 1f 40 00 55 48 89 e5 41 56 41 55 41 54 53 0f 1f 44 00 00 48 89 fb ba 00 00 02 00 <f0> 0f c1 17 89 d0 45 31 e4 45 31 ed c1 e8 10 66 39 d0 41 89 c6 [430033.485174] RIP [<ffffffff816f6898>] _raw_spin_lock+0x18/0xf0 [430033.485370] RSP <ffff88005ae97908> [430033.485566] CR2: 0000000000001088 [430033.486223] ---[ end trace 7264463cd1aac8f9 ]--- [430033.666368] Kernel panic - not syncing: Fatal exception Link: http://lkml.kernel.org/r/20200616183829.87211-4-junxiao.bi@xxxxxxxxxx Signed-off-by: Junxiao Bi <junxiao.bi@xxxxxxxxxx> Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx> Cc: Changwei Ge <gechangwei@xxxxxxx> Cc: Gang He <ghe@xxxxxxxx> Cc: Joel Becker <jlbec@xxxxxxxxxxxx> Cc: Jun Piao <piaojun@xxxxxxxxxx> Cc: Mark Fasheh <mark@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ocfs2/suballoc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/fs/ocfs2/suballoc.c~ocfs2-fix-panic-on-nfs-server-over-ocfs2 +++ a/fs/ocfs2/suballoc.c @@ -2825,9 +2825,12 @@ int ocfs2_test_inode_bit(struct ocfs2_su goto bail; } - inode_alloc_inode = - ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE, - suballoc_slot); + if (suballoc_slot == (u16)OCFS2_INVALID_SLOT) + inode_alloc_inode = ocfs2_get_system_file_inode(osb, + GLOBAL_INODE_ALLOC_SYSTEM_INODE, suballoc_slot); + else + inode_alloc_inode = ocfs2_get_system_file_inode(osb, + INODE_ALLOC_SYSTEM_INODE, suballoc_slot); if (!inode_alloc_inode) { /* the error code could be inaccurate, but we are not able to * get the correct one. */ _
