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BUG: KMSAN: uninit-value in ppp_async_encode drivers/net/ppp/ppp_async.c:550 [inline]
BUG: KMSAN: uninit-value in ppp_async_push+0xbc5/0x2120 drivers/net/ppp/ppp_async.c:680
CPU: 1 PID: 8500 Comm: syz-executor351 Not tainted 5.9.0-rc4-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+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:201
 ppp_async_encode drivers/net/ppp/ppp_async.c:550 [inline]
 ppp_async_push+0xbc5/0x2120 drivers/net/ppp/ppp_async.c:680
 ppp_async_send+0x144/0x1e0 drivers/net/ppp/ppp_async.c:639
 __ppp_channel_push+0x1a7/0x3b0 drivers/net/ppp/ppp_generic.c:1999
 ppp_channel_push drivers/net/ppp/ppp_generic.c:2026 [inline]
 ppp_write+0x785/0x810 drivers/net/ppp/ppp_generic.c:516
 vfs_write+0x69e/0x1860 fs/read_write.c:576
 ksys_write+0x275/0x500 fs/read_write.c:631
 __do_sys_write fs/read_write.c:643 [inline]
 __se_sys_write+0x92/0xb0 fs/read_write.c:640
 __x64_sys_write+0x4a/0x70 fs/read_write.c:640
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x441459
Code: e8 fc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 1b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff40a04248 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441459
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000402200
R13: 0000000000402290 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:143 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:126
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80
 slab_alloc_node mm/slub.c:2907 [inline]
 __kmalloc_node_track_caller+0x9aa/0x12f0 mm/slub.c:4511
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x35f/0xb30 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1094 [inline]
 ppp_write+0x11f/0x810 drivers/net/ppp/ppp_generic.c:500
 vfs_write+0x69e/0x1860 fs/read_write.c:576
 ksys_write+0x275/0x500 fs/read_write.c:631
 __do_sys_write fs/read_write.c:643 [inline]
 __se_sys_write+0x92/0xb0 fs/read_write.c:640
 __x64_sys_write+0x4a/0x70 fs/read_write.c:640
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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