===================================================== BUG: KMSAN: uninit-value in ____bpf_skb_get_nlattr_nest net/core/filter.c:164 [inline] BUG: KMSAN: uninit-value in bpf_skb_get_nlattr_nest+0x14c/0x2f0 net/core/filter.c:154 CPU: 0 PID: 19423 Comm: syz-executor.5 Not tainted 5.8.0-rc5-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+0x1df/0x240 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 ____bpf_skb_get_nlattr_nest net/core/filter.c:164 [inline] bpf_skb_get_nlattr_nest+0x14c/0x2f0 net/core/filter.c:154 ___bpf_prog_run+0x214d/0x97a0 kernel/bpf/core.c:1516 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681 bpf_dispatcher_nop_func include/linux/bpf.h:556 [inline] __bpf_prog_run_save_cb include/linux/filter.h:691 [inline] bpf_prog_run_save_cb include/linux/filter.h:705 [inline] sk_filter_trim_cap+0x42a/0xcc0 net/core/filter.c:119 sk_filter include/linux/filter.h:831 [inline] unix_dgram_sendmsg+0x1987/0x3c30 net/unix/af_unix.c:1710 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] kernel_sendmsg+0x433/0x440 net/socket.c:692 sock_no_sendpage+0x235/0x300 net/core/sock.c:2853 kernel_sendpage net/socket.c:3642 [inline] sock_sendpage+0x1e1/0x2c0 net/socket.c:945 pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:448 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x565/0xf00 fs/splice.c:626 splice_from_pipe fs/splice.c:661 [inline] generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:834 do_splice_from fs/splice.c:846 [inline] do_splice+0x2249/0x30a0 fs/splice.c:1144 __do_sys_splice fs/splice.c:1419 [inline] __se_sys_splice+0x271/0x420 fs/splice.c:1401 __x64_sys_splice+0x6e/0x90 fs/splice.c:1401 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c1d9 Code: Bad RIP value. RSP: 002b:00007f98afe27c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000031a00 RCX: 000000000045c1d9 RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000078bff8 R08: 0000000000010000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac R13: 0000000000c9fb6f R14: 00007f98afe289c0 R15: 000000000078bfac Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165 ___bpf_prog_run+0x6cbe/0x97a0 kernel/bpf/core.c:1391 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681 bpf_dispatcher_nop_func include/linux/bpf.h:556 [inline] __bpf_prog_run_save_cb include/linux/filter.h:691 [inline] bpf_prog_run_save_cb include/linux/filter.h:705 [inline] sk_filter_trim_cap+0x42a/0xcc0 net/core/filter.c:119 sk_filter include/linux/filter.h:831 [inline] unix_dgram_sendmsg+0x1987/0x3c30 net/unix/af_unix.c:1710 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] kernel_sendmsg+0x433/0x440 net/socket.c:692 sock_no_sendpage+0x235/0x300 net/core/sock.c:2853 kernel_sendpage net/socket.c:3642 [inline] sock_sendpage+0x1e1/0x2c0 net/socket.c:945 pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:448 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x565/0xf00 fs/splice.c:626 splice_from_pipe fs/splice.c:661 [inline] generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:834 do_splice_from fs/splice.c:846 [inline] do_splice+0x2249/0x30a0 fs/splice.c:1144 __do_sys_splice fs/splice.c:1419 [inline] __se_sys_splice+0x271/0x420 fs/splice.c:1401 __x64_sys_splice+0x6e/0x90 fs/splice.c:1401 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165 ___bpf_prog_run+0x6c64/0x97a0 kernel/bpf/core.c:1391 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681 bpf_dispatcher_nop_func include/linux/bpf.h:556 [inline] __bpf_prog_run_save_cb include/linux/filter.h:691 [inline] bpf_prog_run_save_cb include/linux/filter.h:705 [inline] sk_filter_trim_cap+0x42a/0xcc0 net/core/filter.c:119 sk_filter include/linux/filter.h:831 [inline] unix_dgram_sendmsg+0x1987/0x3c30 net/unix/af_unix.c:1710 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] kernel_sendmsg+0x433/0x440 net/socket.c:692 sock_no_sendpage+0x235/0x300 net/core/sock.c:2853 kernel_sendpage net/socket.c:3642 [inline] sock_sendpage+0x1e1/0x2c0 net/socket.c:945 pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:448 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x565/0xf00 fs/splice.c:626 splice_from_pipe fs/splice.c:661 [inline] generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:834 do_splice_from fs/splice.c:846 [inline] do_splice+0x2249/0x30a0 fs/splice.c:1144 __do_sys_splice fs/splice.c:1419 [inline] __se_sys_splice+0x271/0x420 fs/splice.c:1401 __x64_sys_splice+0x6e/0x90 fs/splice.c:1401 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Local variable ----regs@__bpf_prog_run32 created at: __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681 __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681 =====================================================