===================================================== BUG: KMSAN: uninit-value in ppp_async_encode drivers/net/ppp/ppp_async.c:551 [inline] BUG: KMSAN: uninit-value in ppp_async_push+0xd0b/0x21a0 drivers/net/ppp/ppp_async.c:681 CPU: 0 PID: 12774 Comm: syz-executor.1 Not tainted 5.12.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x24c/0x2e0 lib/dump_stack.c:120 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197 ppp_async_encode drivers/net/ppp/ppp_async.c:551 [inline] ppp_async_push+0xd0b/0x21a0 drivers/net/ppp/ppp_async.c:681 ppp_async_send+0x144/0x1e0 drivers/net/ppp/ppp_async.c:640 __ppp_channel_push+0x1a7/0x3b0 drivers/net/ppp/ppp_generic.c:2109 ppp_channel_push drivers/net/ppp/ppp_generic.c:2136 [inline] ppp_write+0x785/0x810 drivers/net/ppp/ppp_generic.c:517 vfs_write+0x6cc/0x1b00 fs/read_write.c:603 ksys_write+0x275/0x500 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:667 __ia32_sys_write+0x4a/0x70 fs/read_write.c:667 do_syscall_32_irqs_on arch/x86/entry/common.c:79 [inline] __do_fast_syscall_32+0x127/0x180 arch/x86/entry/common.c:142 do_fast_syscall_32+0x77/0xd0 arch/x86/entry/common.c:168 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:211 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf7f9d549 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f55975fc EFLAGS: 00000296 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:120 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:103 kmsan_slab_alloc+0x8e/0xe0 mm/kmsan/kmsan_hooks.c:76 slab_alloc_node mm/slub.c:2922 [inline] __kmalloc_node_track_caller+0xa4f/0x1470 mm/slub.c:4609 kmalloc_reserve net/core/skbuff.c:353 [inline] __alloc_skb+0x4dd/0xe90 net/core/skbuff.c:424 alloc_skb include/linux/skbuff.h:1103 [inline] ppp_write+0x11f/0x810 drivers/net/ppp/ppp_generic.c:501 vfs_write+0x6cc/0x1b00 fs/read_write.c:603 ksys_write+0x275/0x500 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:667 __ia32_sys_write+0x4a/0x70 fs/read_write.c:667 do_syscall_32_irqs_on arch/x86/entry/common.c:79 [inline] __do_fast_syscall_32+0x127/0x180 arch/x86/entry/common.c:142 do_fast_syscall_32+0x77/0xd0 arch/x86/entry/common.c:168 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:211 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c =====================================================