On Thu, Aug 11, 2022 at 01:47:40AM +0800, D. Wythe wrote: > From: "D. Wythe" <alibuda@xxxxxxxxxxxxxxxxx> > > After we optimize the parallel capability of SMC-R connection > establishment, there is a certain chance to trigger the > following panic: > > PID: 5900 TASK: ffff88c1c8af4100 CPU: 1 COMMAND: "kworker/1:48" > #0 [ffff9456c1cc79a0] machine_kexec at ffffffff870665b7 > #1 [ffff9456c1cc79f0] __crash_kexec at ffffffff871b4c7a > #2 [ffff9456c1cc7ab0] crash_kexec at ffffffff871b5b60 > #3 [ffff9456c1cc7ac0] oops_end at ffffffff87026ce7 > #4 [ffff9456c1cc7ae0] page_fault_oops at ffffffff87075715 > #5 [ffff9456c1cc7b58] exc_page_fault at ffffffff87ad0654 > #6 [ffff9456c1cc7b80] asm_exc_page_fault at ffffffff87c00b62 > [exception RIP: ib_alloc_mr+19] > RIP: ffffffffc0c9cce3 RSP: ffff9456c1cc7c38 RFLAGS: 00010202 > RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000004 > RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffff88c1ea281d00 R8: 000000020a34ffff R9: ffff88c1350bbb20 > R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 > R13: 0000000000000010 R14: ffff88c1ab040a50 R15: ffff88c1ea281d00 > ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 > #7 [ffff9456c1cc7c60] smc_ib_get_memory_region at ffffffffc0aff6df [smc] > #8 [ffff9456c1cc7c88] smcr_buf_map_link at ffffffffc0b0278c [smc] > #9 [ffff9456c1cc7ce0] __smc_buf_create at ffffffffc0b03586 [smc] > > The reason here is that when the server tries to create a second link, > smc_llc_srv_add_link() has no protection and may add a new link to > link group. This breaks the security environment protected by > llc_conf_mutex. > > Signed-off-by: D. Wythe <alibuda@xxxxxxxxxxxxxxxxx> I am curious if this patch can be merged with the previous one? It seems that this panic is introduced by previous one? > --- > net/smc/af_smc.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c > index 39dbf39..0b0c53a 100644 > --- a/net/smc/af_smc.c > +++ b/net/smc/af_smc.c > @@ -1834,8 +1834,10 @@ static int smcr_serv_conf_first_link(struct smc_sock *smc) > smc_llc_link_active(link); > smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE); > > + down_write(&link->lgr->llc_conf_mutex); > /* initial contact - try to establish second link */ > smc_llc_srv_add_link(link, NULL); > + up_write(&link->lgr->llc_conf_mutex); > return 0; > } > > -- > 1.8.3.1
