From: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx>
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 <mike.marciniszyn@xxxxxxxxx>
Reviewed-by: Kaike Wan <kaike.wan@xxxxxxxxx>
Reviewed-by: Alex Estrin <alex.estrin@xxxxxxxxx>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx>
---
drivers/infiniband/core/netlink.c | 13 ++++++++++++-
1 files changed, 12 insertions(+), 1 deletions(-)
diff --git a/drivers/infiniband/core/netlink.c b/drivers/infiniband/core/netlink.c
index b12e587..1fb72c3 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)
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
