84c3833a93
[ Upstream commit 9dbe086c69b8902c85cece394760ac212e9e4ccc ]
A crash was found when dumping SMC-R connections. It can be reproduced
by following steps:
- environment: two RNICs on both sides.
- run SMC-R between two sides, now a SMC_LGR_SYMMETRIC type link group
will be created.
- set the first RNIC down on either side and link group will turn to
SMC_LGR_ASYMMETRIC_LOCAL then.
- run 'smcss -R' and the crash will be triggered.
BUG: kernel NULL pointer dereference, address: 0000000000000010
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 8000000101fdd067 P4D 8000000101fdd067 PUD 10ce46067 PMD 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 3 PID: 1810 Comm: smcss Kdump: loaded Tainted: G W E 6.7.0-rc6+ #51
RIP: 0010:__smc_diag_dump.constprop.0+0x36e/0x620 [smc_diag]
Call Trace:
<TASK>
? __die+0x24/0x70
? page_fault_oops+0x66/0x150
? exc_page_fault+0x69/0x140
? asm_exc_page_fault+0x26/0x30
? __smc_diag_dump.constprop.0+0x36e/0x620 [smc_diag]
smc_diag_dump_proto+0xd0/0xf0 [smc_diag]
smc_diag_dump+0x26/0x60 [smc_diag]
netlink_dump+0x19f/0x320
__netlink_dump_start+0x1dc/0x300
smc_diag_handler_dump+0x6a/0x80 [smc_diag]
? __pfx_smc_diag_dump+0x10/0x10 [smc_diag]
sock_diag_rcv_msg+0x121/0x140
? __pfx_sock_diag_rcv_msg+0x10/0x10
netlink_rcv_skb+0x5a/0x110
sock_diag_rcv+0x28/0x40
netlink_unicast+0x22a/0x330
netlink_sendmsg+0x240/0x4a0
__sock_sendmsg+0xb0/0xc0
____sys_sendmsg+0x24e/0x300
? copy_msghdr_from_user+0x62/0x80
___sys_sendmsg+0x7c/0xd0
? __do_fault+0x34/0x1a0
? do_read_fault+0x5f/0x100
? do_fault+0xb0/0x110
__sys_sendmsg+0x4d/0x80
do_syscall_64+0x45/0xf0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
When the first RNIC is set down, the lgr->lnk[0] will be cleared and an
asymmetric link will be allocated in lgr->link[SMC_LINKS_PER_LGR_MAX - 1]
by smc_llc_alloc_alt_link(). Then when we try to dump SMC-R connections
in __smc_diag_dump(), the invalid lgr->lnk[0] will be accessed, resulting
in this issue. So fix it by accessing the right link.
Fixes:
|
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| af_smc.c | ||
| smc.h | ||
| smc_cdc.c | ||
| smc_cdc.h | ||
| smc_clc.c | ||
| smc_clc.h | ||
| smc_close.c | ||
| smc_close.h | ||
| smc_core.c | ||
| smc_core.h | ||
| smc_diag.c | ||
| smc_ib.c | ||
| smc_ib.h | ||
| smc_ism.c | ||
| smc_ism.h | ||
| smc_llc.c | ||
| smc_llc.h | ||
| smc_netlink.c | ||
| smc_netlink.h | ||
| smc_netns.h | ||
| smc_pnet.c | ||
| smc_pnet.h | ||
| smc_rx.c | ||
| smc_rx.h | ||
| smc_stats.c | ||
| smc_stats.h | ||
| smc_sysctl.c | ||
| smc_sysctl.h | ||
| smc_tracepoint.c | ||
| smc_tracepoint.h | ||
| smc_tx.c | ||
| smc_tx.h | ||
| smc_wr.c | ||
| smc_wr.h | ||