On Tue, Oct 03, 2017 at 10:25:22AM +0800, Jia-Ju Bai wrote: > The SCTP program may sleep under a spinlock, and the function call path is: > sctp_generate_t3_rtx_event (acquire the spinlock) > sctp_do_sm > sctp_side_effects > sctp_cmd_interpreter > sctp_make_init_ack > sctp_pack_cookie > crypto_shash_setkey > shash_setkey_unaligned > kmalloc(GFP_KERNEL) Are you sure this can happen? The host is not supposed to store any information when replying to an INIT packet (which generated the INIT_ACK listed above). That said, it's weird to see the timer function triggering so. Checking now, that code is dead actually: $ git grep -A 2 SCTP_CMD_GEN_INIT_ACK sm_sideeffect.c: case SCTP_CMD_GEN_INIT_ACK: sm_sideeffect.c- /* Generate an INIT ACK chunk. */ sm_sideeffect.c- new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC, Nobody is triggering a call to sctp_cmd_interpreter with SCTP_CMD_GEN_INIT_ACK command, which would generate the callstack above. Marcelo
