From b4d91aeb6e120b7e2f207021c31b914895c69bc4 Mon Sep 17 00:00:00 2001 From: "Michael J. Ruhl" Date: Tue, 24 Oct 2017 08:41:01 -0400 Subject: [PATCH] RDMA/netlink: OOPs in rdma_nl_rcv_msg() from misinterpreted flag rdma_nl_rcv_msg() checks to see if it should use the .dump() callback or the .doit() callback. The check is done with this check: if (flags & NLM_F_DUMP) ... The NLM_F_DUMP flag is two bits (NLM_F_ROOT | NLM_F_MATCH). When an RDMA_NL_LS message (response) is received, the bit used for indicating an error is the same bit as NLM_F_ROOT. NLM_F_ROOT == (0x100) == RDMA_NL_LS_F_ERR. ibacm sends a response with the RDMA_NL_LS_F_ERR bit set if an error occurs in the service. The current code then misinterprets the NLM_F_DUMP bit and trys to call the .dump() callback. If the .dump() callback for the specified request is not available (which is true for the RDMA_NL_LS messages) the following Oops occurs: [ 4555.960256] BUG: unable to handle kernel NULL pointer dereference at (null) [ 4555.969046] IP: (null) [ 4555.972664] PGD 10543f1067 P4D 10543f1067 PUD 1033f93067 PMD 0 [ 4555.979287] Oops: 0010 [#1] SMP [ 4555.982809] Modules linked in: rpcrdma ib_isert iscsi_target_mod target_core_mod ib_iser libiscsi scsi_transport_iscsi ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm dm_mirror dm_region_hash dm_log dm_mod dax sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel crypto_simd glue_helper cryptd hfi1 rdmavt iTCO_wdt iTCO_vendor_support ib_core mei_me lpc_ich pcspkr mei ioatdma sg shpchp i2c_i801 mfd_core wmi ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter acpi_pad nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables ext4 mbcache jbd2 sd_mod mgag200 drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm igb ahci crc32c_intel ptp libahci pps_core drm dca libata i2c_algo_bit i2c_core [ 4556.061190] CPU: 54 PID: 9841 Comm: ibacm Tainted: G I 4.14.0-rc2+ #6 [ 4556.069667] Hardware name: Intel Corporation S2600WT2/S2600WT2, BIOS SE5C610.86B.01.01.0008.021120151325 02/11/2015 [ 4556.081339] task: ffff880855f42d00 task.stack: ffffc900246b4000 [ 4556.087967] RIP: 0010: (null) [ 4556.092166] RSP: 0018:ffffc900246b7bc8 EFLAGS: 00010246 [ 4556.098018] RAX: ffffffff81dbe9e0 RBX: ffff881058bb1000 RCX: 0000000000000000 [ 4556.105997] RDX: 0000000000001100 RSI: ffff881058bb1320 RDI: ffff881056362000 [ 4556.113984] RBP: ffffc900246b7bf8 R08: 0000000000000ec0 R09: 0000000000001100 [ 4556.121971] R10: ffff8810573a5000 R11: 0000000000000000 R12: ffff881056362000 [ 4556.129957] R13: 0000000000000ec0 R14: ffff881058bb1320 R15: 0000000000000ec0 [ 4556.137945] FS: 00007fe0ba5a38c0(0000) GS:ffff88105f080000(0000) knlGS:0000000000000000 [ 4556.147000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4556.153433] CR2: 0000000000000000 CR3: 0000001056f5d003 CR4: 00000000001606e0 [ 4556.161419] Call Trace: [ 4556.164167] ? netlink_dump+0x12c/0x290 [ 4556.168468] __netlink_dump_start+0x186/0x1f0 [ 4556.173357] rdma_nl_rcv_msg+0x193/0x1b0 [ib_core] [ 4556.178724] rdma_nl_rcv+0xdc/0x130 [ib_core] [ 4556.183604] netlink_unicast+0x181/0x240 [ 4556.187998] netlink_sendmsg+0x2c2/0x3b0 [ 4556.192392] sock_sendmsg+0x38/0x50 [ 4556.196299] SYSC_sendto+0x102/0x190 [ 4556.200308] ? __audit_syscall_entry+0xaf/0x100 [ 4556.205387] ? syscall_trace_enter+0x1d0/0x2b0 [ 4556.210366] ? __audit_syscall_exit+0x209/0x290 [ 4556.215442] SyS_sendto+0xe/0x10 [ 4556.219060] do_syscall_64+0x67/0x1b0 [ 4556.223165] entry_SYSCALL64_slow_path+0x25/0x25 [ 4556.228328] RIP: 0033:0x7fe0b9db2a63 [ 4556.232333] RSP: 002b:00007ffc55edc260 EFLAGS: 00000293 ORIG_RAX: 000000000000002c [ 4556.240808] RAX: ffffffffffffffda RBX: 0000000000000010 RCX: 00007fe0b9db2a63 [ 4556.248796] RDX: 0000000000000010 RSI: 00007ffc55edc280 RDI: 000000000000000d [ 4556.256782] RBP: 00007ffc55edc670 R08: 00007ffc55edc270 R09: 000000000000000c [ 4556.265321] R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffc55edc280 [ 4556.273846] R13: 000000000260b400 R14: 000000000000000d R15: 0000000000000001 [ 4556.282368] Code: Bad RIP value. [ 4556.286629] RIP: (null) RSP: ffffc900246b7bc8 [ 4556.293013] CR2: 0000000000000000 [ 4556.297292] ---[ end trace 8d67abcfd10ec209 ]--- [ 4556.305465] Kernel panic - not syncing: Fatal exception [ 4556.313786] Kernel Offset: disabled [ 4556.321563] ---[ end Kernel panic - not syncing: Fatal exception [ 4556.328960] ------------[ cut here ]------------ Special case RDMA_NL_LS response messages to call the appropriate callback. Additionally, make sure that the .dump() callback is not NULL before calling it. Fixes: 647c75ac59a48a54 ("RDMA/netlink: Convert LS to doit callback") Reviewed-by: Mike Marciniszyn Reviewed-by: Kaike Wan Reviewed-by: Alex Estrin Signed-off-by: Michael J. Ruhl Reviewed-by: Shiraz Saleem Signed-off-by: Doug Ledford --- drivers/infiniband/core/netlink.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/core/netlink.c b/drivers/infiniband/core/netlink.c index b12e58787c3d..1fb72c356e36 100644 --- a/drivers/infiniband/core/netlink.c +++ b/drivers/infiniband/core/netlink.c @@ -175,13 +175,24 @@ static int rdma_nl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, !netlink_capable(skb, CAP_NET_ADMIN)) return -EPERM; + /* + * LS responses overload the 0x100 (NLM_F_ROOT) flag. Don't + * mistakenly call the .dump() function. + */ + if (index == RDMA_NL_LS) { + if (cb_table[op].doit) + return cb_table[op].doit(skb, nlh, extack); + return -EINVAL; + } /* FIXME: Convert IWCM to properly handle doit callbacks */ if ((nlh->nlmsg_flags & NLM_F_DUMP) || index == RDMA_NL_RDMA_CM || index == RDMA_NL_IWCM) { struct netlink_dump_control c = { .dump = cb_table[op].dump, }; - return netlink_dump_start(nls, skb, nlh, &c); + if (c.dump) + return netlink_dump_start(nls, skb, nlh, &c); + return -EINVAL; } if (cb_table[op].doit) -- GitLab