================================================================== BUG: KASAN: stack-out-of-bounds in csd_lock_record+0xd2/0xe0 kernel/smp.c:119 Read of size 8 at addr ffffc90000dd7978 by task syz-executor.4/10614 CPU: 1 PID: 10614 Comm: syz-executor.4 Not tainted 5.8.0-rc3-next-20200703-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0x5/0x436 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 csd_lock_record+0xd2/0xe0 kernel/smp.c:119 flush_smp_call_function_queue+0x285/0x730 kernel/smp.c:391 __sysvec_call_function_single+0x98/0x490 arch/x86/kernel/smp.c:248 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_call_function_single+0xe0/0x120 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:604 RIP: 0010:kernel_text_address+0x0/0xf0 kernel/extable.c:121 Code: ce 66 0f 1f 84 00 00 00 00 00 31 c0 48 81 ff 00 00 a0 89 72 0c 31 c0 48 81 ff 40 0e b1 8a 0f 92 c0 c3 0f 1f 84 00 00 00 00 00 <55> 48 89 fd 48 83 ec 08 48 81 ff 00 00 00 81 72 09 48 81 ff 83 1c RSP: 0018:ffffc90003daeea8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffffff81b37f4f RCX: 0000000000000000 RDX: 1ffff920007b5de4 RSI: 0000000000000001 RDI: ffffffff81b37f4f RBP: ffffc90003daef20 R08: ffffffff8b22ff8e R09: ffffffff8b22ff92 R10: 000000000007201e R11: 0000000000000001 R12: ffffc90003daef90 R13: 0000000000000000 R14: ffff8880530ec280 R15: 0000000000000040 __kernel_text_address+0x9/0x30 kernel/extable.c:105 unwind_get_return_address arch/x86/kernel/unwind_orc.c:317 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:312 arch_stack_walk+0x97/0xf0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:494 slab_post_alloc_hook mm/slab.h:535 [inline] slab_alloc mm/slab.c:3316 [inline] kmem_cache_alloc_trace+0x14d/0x480 mm/slab.c:3552 kmalloc include/linux/slab.h:554 [inline] sctp_datamsg_new net/sctp/chunk.c:50 [inline] sctp_datamsg_from_user+0x86/0x11e0 net/sctp/chunk.c:158 sctp_sendmsg_to_asoc+0xbee/0x2090 net/sctp/socket.c:1866 sctp_sendmsg+0x1025/0x1cf0 net/sctp/socket.c:2038 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:814 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 sock_no_sendpage+0xee/0x130 net/core/sock.c:2844 kernel_sendpage net/socket.c:3644 [inline] sock_sendpage+0x113/0x140 net/socket.c:945 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:448 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x3dc/0x830 fs/splice.c:626 splice_from_pipe fs/splice.c:661 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:834 do_splice_from fs/splice.c:846 [inline] direct_splice_actor+0x171/0x2f0 fs/splice.c:1016 splice_direct_to_actor+0x38c/0x980 fs/splice.c:971 do_splice_direct+0x1b3/0x280 fs/splice.c:1059 do_sendfile+0x559/0xc30 fs/read_write.c:1521 __do_sys_sendfile64 fs/read_write.c:1582 [inline] __se_sys_sendfile64 fs/read_write.c:1568 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1568 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:367 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cb29 Code: Bad RIP value. RSP: 002b:00007fc960cafc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000004fd720 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 000080001d00c0d0 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000902 R14: 00000000004cbe0a R15: 00007fc960cb06d4 Memory state around the buggy address: ffffc90000dd7800: 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 ffffc90000dd7880: 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 00 >ffffc90000dd7900: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 ^ ffffc90000dd7980: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00 ffffc90000dd7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================