On Thu, Jul 16, 2020 at 01:55:19PM +0300, Leon Romanovsky wrote: > From: Maor Gottlieb <maorg@xxxxxxxxxxxx> > > cm.lock must be held while access to remote_sidr_table. > This fix the below NULL pointer dereference. > > [ 2666.146138] BUG: kernel NULL pointer dereference, address: 0000000000000000 > [ 2666.151565] #PF: supervisor write access in kernel mode > [ 2666.152896] #PF: error_code(0x0002) - not-present page > [ 2666.154184] PGD 0 P4D 0 > [ 2666.154911] Oops: 0002 [#1] SMP PTI > [ 2666.155859] CPU: 2 PID: 7288 Comm: udaddy Not tainted 5.7.0_for_upstream_perf_2020_06_09_15_14_20_38 #1 > [ 2666.158123] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 > [ 2666.161909] RIP: 0010:rb_erase+0x10d/0x360 > [ 2666.163549] Code: 00 00 00 48 89 c1 48 89 d0 48 8b 50 08 48 39 ca 74 48 f6 02 01 75 af 48 8b > 7a 10 48 89 c1 48 83 c9 01 48 89 78 08 48 89 42 10 <48> 89 0f 48 8b 08 48 89 0a 48 83 e1 fc 48 > 89 10 0f 84 b1 00 00 00 > [ 2666.169743] RSP: 0018:ffffc90000f77c30 EFLAGS: 00010086 > [ 2666.171646] RAX: ffff8883df27d458 RBX: ffff8883df27da58 RCX: ffff8883df27d459 > [ 2666.174026] RDX: ffff8883d183fa58 RSI: ffffffffa01e8d00 RDI: 0000000000000000 > [ 2666.176325] RBP: ffff8883d62ac800 R08: 0000000000000000 R09: 00000000000000ce > [ 2666.178618] R10: 000000000000000a R11: 0000000000000000 R12: ffff8883df27da00 > [ 2666.180919] R13: ffffc90000f77c98 R14: 0000000000000130 R15: 0000000000000000 > [ 2666.183197] FS: 00007f009f877740(0000) GS:ffff8883f1a00000(0000) knlGS:0000000000000000 > [ 2666.186318] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 2666.188293] CR2: 0000000000000000 CR3: 00000003d467e003 CR4: 0000000000160ee0 > [ 2666.190614] Call Trace: > [ 2666.191896] cm_send_sidr_rep_locked+0x15a/0x1a0 [ib_cm] > [ 2666.193902] ib_send_cm_sidr_rep+0x2b/0x50 [ib_cm] > [ 2666.195695] cma_send_sidr_rep+0x8b/0xe0 [rdma_cm] > [ 2666.197559] __rdma_accept+0x21d/0x2b0 [rdma_cm] > [ 2666.199335] ? ucma_get_ctx+0x2b/0xe0 [rdma_ucm] > [ 2666.201105] ? _copy_from_user+0x30/0x60 > [ 2666.202741] ucma_accept+0x13e/0x1e0 [rdma_ucm] > [ 2666.204549] ucma_write+0xb4/0x130 [rdma_ucm] > [ 2666.206306] vfs_write+0xad/0x1a0 > [ 2666.207780] ksys_write+0x9d/0xb0 > [ 2666.209316] do_syscall_64+0x48/0x130 > [ 2666.210915] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > [ 2666.212810] RIP: 0033:0x7f009ef60924 > [ 2666.214354] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b > 05 2a ef 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 > 66 90 55 53 48 89 d5 48 89 f3 48 83 > [ 2666.220512] RSP: 002b:00007fff843edf38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 > [ 2666.223546] RAX: ffffffffffffffda RBX: 000055743042e1d0 RCX: 00007f009ef60924 > [ 2666.225889] RDX: 0000000000000130 RSI: 00007fff843edf40 RDI: 0000000000000003 > [ 2666.228228] RBP: 00007fff843ee0e0 R08: 0000000000000000 R09: 0000557430433090 > [ 2666.230572] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 > [ 2666.232931] R13: 00007fff843edf40 R14: 000000000000038c R15: 00000000ffffff00 > [ 2666.235272] Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 > auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache xt_MASQUERADE > mlx5_ib nf_conntrack_netlink nfnetlink iptable_nat xt_addrtype > iptable_filter bpfilter xt_conntrack br_netfilter bridge stp llc overlay > rpcrdma ib_isert iscsi_target_mod ib_iser ib_srpt target_core_mod ib_srp > ib_ipoib rdma_ucm ib_uverbs sb_edac mlx5_core kvm_intel iTCO_wdt > iTCO_vendor_support kvm ib_umad mlxfw pci_hyperv_intf act_ct > nf_flow_table irqbypass nf_nat rdma_cm crc32_pclmul rfkill nf_conntrack > crc32c_intel ghash_clmulni_intel virtio_net ib_cm i2c_i801 pcspkr > nf_defrag_ipv6 net_failover failover nf_defrag_ipv4 ptp i2c_core lpc_ich > iw_cm pps_core mfd_core ib_core sunrpc sch_fq_codel ip_tables serio_raw > [ 2666.258905] CR2: 0000000000000000 > [ 2666.260386] ---[ end trace 92a3d3f267f6faa3 ]--- > [ 2666.262174] RIP: 0010:rb_erase+0x10d/0x360 > [ 2666.263781] Code: 00 00 00 48 89 c1 48 89 d0 48 8b 50 08 48 39 ca 74 > 48 f6 02 01 75 af 48 8b 7a 10 48 89 c1 48 83 c9 01 48 89 78 08 48 89 42 > 10 <48> 89 0f 48 8b 08 48 89 0a 48 83 e1 fc 48 89 10 0f 84 b1 00 00 > 00 > [ 2666.269994] RSP: 0018:ffffc90000f77c30 EFLAGS: 00010086 > [ 2666.272008] RAX: ffff8883df27d458 RBX: ffff8883df27da58 RCX: ffff8883df27d459 > [ 2666.274465] RDX: ffff8883d183fa58 RSI: ffffffffa01e8d00 RDI: 0000000000000000 > [ 2666.276978] RBP: ffff8883d62ac800 R08: 0000000000000000 R09: 00000000000000ce > [ 2666.279437] R10: 000000000000000a R11: 0000000000000000 R12: ffff8883df27da00 > [ 2666.281941] R13: ffffc90000f77c98 R14: 0000000000000130 R15: 0000000000000000 > [ 2666.284397] FS: 00007f009f877740(0000) GS:ffff8883f1a00000(0000) knlGS:0000000000000000 > [ 2666.287708] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 2666.289817] CR2: 0000000000000000 CR3: 00000003d467e003 CR4: 0000000000160ee0 > [ 2666.292274] Kernel panic - not syncing: Fatal exception > [ 2666.294689] Kernel Offset: disabled > [ 2666.296253] ---[ end Kernel panic - not syncing: Fatal exception]--- Don't word wrap oops reports, and I prefer the timestamp is stripped out > Fixes: 6a8824a74bc9 ("RDMA/cm: Allow ib_send_cm_sidr_rep() to be done under lock") > Signed-off-by: Maor Gottlieb <maorg@xxxxxxxxxxxx> > Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx> > --- > drivers/infiniband/core/cm.c | 2 ++ > 1 file changed, 2 insertions(+) Applied to for-rc Thanks, Jason